Air Quality Matters

This week, we dive into a thought-provoking commentary published in the Journal of Health Security titled Catch Me If You Can: Reducing Infectious Disease Through Better Indoor Air Quality and Bio Surveillance, to explore a question that fundamentally challenges how we think about protecting public health: What if the single biggest barrier to preventing the next pandemic isn't our lack of scientific knowledge about airborne pathogens—but the boom and bust cycle of funding that prevents us from building the intelligent, integrated biosurveillance systems our buildings desperately need? The air circulating within our indoor environments is essentially a microscopic soup containing potentially pathogenic bacteria, fungi, mould, and viruses. COVID-19 forced us to radically rethink how indoor air quality mitigates disease transmission. But the authors argue that to truly protect critical building infrastructure, we have to integrate our existing HVAC systems with active biosurveillance—meaning continuous detection of environmental flora and microbes. Key Topics Discussed: The Unintended Consequence of Energy Savings: Legionella, the bacteria responsible for Legionnaires disease, loves warm, stagnant water. To save energy, many building operators have lowered their water heat temperatures. By dropping those temperatures down to between 25 and 45 degrees, they inadvertently created the perfect conditions for this bacteria to proliferate. Post COVID, as buildings reopened, stagnant water sitting in pipes was suddenly aerosolized through taps and showers, leading to increased Legionella outbreaks. When we pull one lever in a building like energy efficiency, we can inadvertently create a massive public health hazard. The Needle in a Haystack: The US government's BioWatch program, created after the 2001 anthrax letter attacks, deployed air monitoring units to detect intentional biological threats. In practice, it's incredibly clunky. The systems require actual human beings to manually retrieve samples and carry them to the lab. The tests rely on prior research, meaning the system is only looking for threats it has been programmed to find. If a brand new or engineered pathogen is floating through the air, the system might completely miss it. Schools as Petri Dishes: Viral respiratory pathogens spread like wildfires in schools due to high occupancy density and prolonged indoor exposure. We already know how to fix this. Improving ventilation, adding HEPA filtration, and monitoring carbon dioxide significantly reduces pathogen exposure. In one trial across Los Angeles unified school districts, simply adding portable HEPA filters to classrooms reduced PM 2.5 concentrations by up to 82%. The problem is not the lack of knowledge. It's a lack of resources. The Flaws in Our Math: We use sophisticated risk assessment models like the Wells Riley model to predict the probability of infection based on room size, ventilation rates, exposure time, and filter efficiency. These models are incredibly useful, but they have glaring blind spots. They rely heavily on steady state assumptions, assuming occupancy, ventilation rates, and pathogen shedding remain constant. They also assume that the air in a room mixes perfectly. To get this right, we need real time sensor data integrated with building controls to dynamically adjust ventilation based on actual conditions. Catch Me if You Can: Reducing Infectious Disease Through Better Indoor Air Quality and Biosurveillance (https://doi.org/10.1177/23265094261418816) The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The One Take Format and the Microscopic Soup We Breathe 00:01:44 The Funding Crisis: Boom and Bust Cycles in Biodefense Research 00:02:34 Case One: Energy Savings vs Legionella—The Unintended Consequence 00:03:41 Case Two: The BioWatch Program—Finding a Needle in a Haystack 00:04:49 Case Three: Schools as Petri Dishes—The Resource Gap 00:05:43 Case Four: The Flaws in Our Math—When Models Meet Reality 00:06:40 The Vicious Cycle: From Reaction to Prevention 00:07:27 The Call to Action: Smart Buildings and Steady Innovation 00:07:46 Closing Thoughts: Staying One Step Ahead of the Next Pathogen

This week, we sit down with Ciaran Byrne, Director of National Retrofit, and Brian McIntyre, Program Manager for High Performance Building Technologies at the Sustainable Energy Authority of Ireland (SEAI), to explore a question that fundamentally challenges how we think about decarbonising the built environment: Key Topics Discussed: The Energy Security Reality: You can't control the cost of energy, but you can control how much energy your building needs. Ireland imports nearly all its fossil fuels, leaving households exposed to volatile global markets. The recent energy crisis has created a monthly reminder in every electricity and heating bill that decoupling from energy dependence isn't just environmental—it's economic survival. Retrofit isn't rocket science. It's far harder. It's mass customisation at a national scale. Always On Schemes and Multi Annual Funding: SEAI moved away from opening and closing grant windows, creating always on schemes with clear, commoditised grant amounts. No more guessing. No more waiting. Contractors know exactly what funding is available, homeowners know exactly what they'll receive, and the carbon tax was ring fenced to provide multi annual certainty out to 2030. This allowed industry to invest in skills, equipment, and capacity without the boom and bust cycles that plagued previous decades. The Skills and Labour Challenge: Ireland needs an estimated 50,000 additional skilled trades to deliver retrofit at scale. New build offers straightforward, repetitive work on identical house types. Retrofit is mass customisation—every home is different, every household has unique needs, and crossing the threshold into someone's home requires soft skills, customer service, and technical adaptability. Retrofit is a local career. It's nationwide work. It's a legacy you leave in your own community. GUESTS: Ciaran Byrne Director of National Retrofit, Sustainable Energy Authority of Ireland https://www.linkedin.com/in/dr-ciaran-byrne-c-dir-1024682a/ Brian McIntyre Program Manager, High Performance Building Technologies, Sustainable Energy Authority of Ireland https://www.linkedin.com/in/brian-mcintyre-b6474838/ SEAI https://www.seai.ie/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) S&P UK (https://www.solerpalau.com/en-uk/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) - Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) - iE Electronics (https://www.eielectronics.ie/) and iAir Group (https://iair-group.com/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Meeting SEAI and Ireland's Decarbonisation Mission 00:02:22 Energy Security and the Controllables: Why Fabric First Still Matters 00:08:40 SEAI's Role: From Energy Agency to National Retrofit Delivery Body 00:11:32 The Game-Changing Reforms: Always-On Schemes and Commoditized Grants 00:22:03 Demand Generation: From Ukraine War to Energy Bills as Monthly Reminders 00:24:49 Going Mainstream: When Retrofit Becomes Common Knowledge 00:30:54 Beyond Energy Savings: The Comfort, Health, and Well-Being Case 00:38:38 Affordability and the Hidden Energy Poor: Who Gets Left Behind 00:48:01 The Skills and Labour Challenge: Competing with New Build 00:57:34 Quality Control and Avoiding the Horror Stories 00:50:02 The Data Revolution: From Static BER to Real-Time Building Performance 01:22:30 The Next Five Years: Digital Journeys, High-Temperature Heat Pumps, and AI 01:37:13 Closing Thoughts: Making Retrofit as Easy as Ordering from Amazon

This week, we dive into a fascinating paper from the Journal of Sustainable Futures titled Co-creating Sustainable Innovations in Irish Social Housing Through Participatory Research, to explore a question that fundamentally challenges how we think about indoor air quality intervention: What if the single biggest barrier to deploying environmental sensors in homes isn't the technology—but the complete absence of trust, agency, and meaningful participation from the people whose living rooms we're trying to monitor? In Ireland, social housing providers act as landlords responsible for repair, maintenance, and dealing with problems like dampness and mould. But their strategy is almost entirely reactive—waiting for residents to call and report a problem. By the time that call is made, the resident has likely already been exposed to harmful levels of damp and mould for a prolonged period, and the building's infrastructure may already be compromised. The SHINE project (Sustainable Homes Integrating Non-Intrusive Environmental Sensors) aimed to transition from reactive maintenance to proactive monitoring using low cost environmental sensors. But the researchers knew they couldn't just drop technology into people's living rooms without asking them first. Key Topics Discussed: The Historical Baggage Problem: Top down regeneration and sustainability projects in Ireland have a shaky track record. Dolphin House residents spent over a decade fighting for regeneration due to horrific living conditions and severe mould. Despite 25 million allocated in 2016, years later only a fraction has been retrofitted. When you have that kind of historical baggage, trust is understandably low. The Fear of Surveillance and Data Exploitation: When you tell someone you're putting a sensor in their home, their mind immediately jumps to surveillance. Residents worried landlords were spying on them, recording audio and video, that data would be weaponised to evict them. What if environmental data showing a resident lived in a damp, mouldy home found its way to a health insurance provider? It could literally affect their ability to get coverage for lung conditions. The Challenge of Meaningful Participation: Consultations can easily turn into forums for venting. Stakeholders advised that the project had to clearly answer the resident's fundamental question: what's in it for us? If sensors are just seen as a tool for the landlord to save money on maintenance, residents will push back. The narrative has to focus on how sensors save the resident's time, reduce their bills, and protect their health. The Blame Narrative Problem: For years, the narrative around mould has been to blame the resident—telling them they just aren't opening their windows enough or they're drying too many clothes indoors. Approaching residents with a patronising or blaming tone will cause them to instantly refuse participation. Co-creating sustainable innovations in Irish social housing through participatory research https://doi.org/10.1016/j.sftr.2026.101740 The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The One Take Format and the Participatory Research Paper 00:01:11 The Reactive Maintenance Problem: When Waiting Means Harm 00:01:54 The SHINE Project: Shifting from Reactive to Proactive Monitoring 00:02:35 The Historical Baggage: Why Top-Down Projects Fail in Ireland 00:03:49 The Participatory Research Approach: 28 Stakeholder Voices 00:04:27 Barrier One: The Fear of Surveillance and Data Exploitation 00:05:40 Barrier Two: The Challenge of Meaningful Participation 00:06:32 Barrier Three: Specific Needs of Vulnerable Populations 00:07:25 The Engineering Response: Data Minimization and Edge Computing 00:08:10 Flipping the Power Dynamic: User Control and Inert Design 00:09:16 The Real Barrier: Participation by Design, Not Technology 00:10:09 Closing Thoughts: Listening First, Building Better

This week, we sit down with Kwok Wai THam, President of Indoor Air 2026 with Vice Presidents, Yvonne Soh, and Chandra Sekhar, to explore a question that fundamentally challenges how we think about the evolution of indoor air quality: What if the single most important shift in the last two decades isn't just our deeper understanding of the science—but our recognition that clean indoor air is now a fundamental human right, requiring resilience, technology, and human centric design to deliver? Key Topics Discussed: From Reactive to Proactive: In 2003, the focus was on sick building syndrome and reactive maintenance. In 2026, the conversation has shifted to proactive biosurveillance, real-time sensor networks, and predictive analytics powered by artificial intelligence. Buildings are no longer passive containers. They are intelligent systems capable of detecting, responding to, and mitigating indoor air quality problems before occupants even notice. The Complexity Problem: Indoor environments are more complex than ever. New synthetic materials off-gas volatile organic compounds. Occupancy densities have increased. External pollution from wildfires, traffic, and industrial sources infiltrates buildings faster than ventilation systems can respond. And climate change is compounding thermal discomfort, humidity challenges, and energy demands. Science has advanced, but so have the problems. Human Centric Design and Adaptive Comfort: Singapore has pioneered mixed-mode ventilation strategies that work with the weather rather than against it. When outdoor conditions are acceptable, buildings switch to natural ventilation. When temperatures rise, air conditioning activates. This approach reduces energy consumption while maintaining thermal comfort. But it requires rethinking occupant expectations, building controls, and system resilience during transient conditions. Fifteen Sub Themes and a Global Conversation: Indoor Air 2026 features fifteen technical sub themes covering everything from source control and materials selection to airborne infectious disease, smart building technology, and policy development. The conference deliberately avoids regional segmentation. Every theme is global. Every challenge is universal. The goal is cross learning—taking lessons from Latin America, Europe, Asia, and North America and applying them everywhere. GUESTS: Prof. Tham Kwok Wai President, Indoor Air 2026 | National University of Singapore https://www.linkedin.com/in/tham-kwok-wai-0623aa44/ Engr. Yvonne Soh Vice President, Indoor Air 2026 | CEO, Singapore Green Building Council https://www.linkedin.com/in/yvonne-soh-0a78934/ Prof. Chandra Sekhar Vice President, Indoor Air 2026 | National University of Singapore https://www.linkedin.com/in/chandra-sekhar/ Indoor Air 2026 https://www.indoorair2026.org/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Welcome to Indoor Air 2026 Preview 00:02:46 Twenty Years of Progress: Reflecting on Indoor Air Since 2003 00:06:48 The Pandemic Parallel: SARS-CoV-1 Then, COVID-19 Now 00:10:22 From Sick Buildings to Human-Centered Design: The Green Building Evolution 00:13:17 The Conference Theme: Enhancing Well-Being Through Resilience and Understanding 00:15:38 Fifteen Sub-Themes: From Source Control to Clean Air Equivalence 00:19:12 The Complexity Challenge: More Knowledge, More Problems 00:22:01 Technology as Enabler: Sensors, Data, and Artificial Intelligence 00:27:10 Singapore as Living Laboratory: Climate, Walkability, and Mixed-Mode Design 00:35:26 The Conference Experience: Venue, Schedule, and Parallel Sessions 00:49:50 Keynote Speakers: From Science to Policy and Translational Impact 00:49:17 Special Events: Global Clean Air Pledge and Medical-Engineering Collaboration 01:00:25 Beyond the Conference Rooms: Technical Tours and Indoors Go Out 01:03:26 Investing in the Future: Summer School and Career Pathways 01:04:39 The Next Generation: Young Professionals and Sustainability Impact 01:09:33 Global Gathering: 900 Delegates from Every Continent

This week, we dive into a fascinating full scale experimental study published in the Journal of Indoor Environments titled Indoor Laundry Drying: Full Scale Determination of Water Emissions Rates and Impact on Thermal Comfort, to explore a question that fundamentally challenges how we think about energy efficiency advice: What if the single most common energy saving recommendation—drying clothes indoors instead of using a tumble dryer—is actually forcing us to turn up the heating and creating serious indoor air quality problems we've never properly quantified? Across Europe, particularly during winter months, over 60% of laundries are dried indoors in countries like Poland, Hungary, Czech Republic, and Finland. In France alone, tumble dryers account for 20% of average annual household electricity consumption. The advice is clear: save energy, ditch the dryer, hang your clothes on a rack. But while we know this practice coincides with dust mite growth and high concentrations of airborne mould spores due to rising moisture, the actual kinetics—how much water is emitted, exactly when, and how it physically changes the room's environment—has never been properly quantified in a controlled, full scale way. Until now. Key Topics Discussed: The Cotton Culprit: A typical four kilogram load of dry cotton towels will hold about two litres of water after a standard 40 degree wash. Spinning faster than 1,000 RPM doesn't extract much more water. Cotton is the real moisture problem when it comes to indoor drying. Three Phases of Drying: By constantly weighing the drying rack and monitoring room humidity in a controlled 40 cubic metre experimental chamber, researchers discovered water emission isn't a slow, steady trickle. It happens in three distinct phases: the initial burst (first two hours, exceeding 100 grams per hour, peaking at 360 grams per hour), the steady state (10 to 25 hours, stabilizing around 50 grams per hour as the room becomes humid), and the exhaustion phase (beyond 30 hours, gradually tailing off). The Temperature Drop Problem: Evaporating water is endothermic—it literally sucks heat out of surrounding air. As laundry dried, room temperature dropped significantly, recording drops between half a degree and 3.8 degrees Celsius. If your room starts off quite dry, the initial humidity gradient is higher, water evaporates faster, and the temperature drop is even sharper. The Thermal Comfort Failure: When researchers mapped these temperature and humidity changes onto standard thermal comfort charts like ASHRAE 55, the results were clear: passive indoor laundry drying actively drags room conditions right out of acceptable comfort zones. Even wearing thicker winter clothes only partially mitigates the discomfort. The Heating Paradox: If we're told to avoid tumble dryers to save energy, but doing so drops the temperature of our living spaces by almost four degrees, what do we inevitably do? We turn up the central heating. The energy saving advice creates a new energy consumption problem. Mitigation Strategies: We need to be strategic about where we dry clothes. Positioning drying racks in bathrooms close to air extraction points can avoid spreading moisture and physically cooling down living and sleeping spaces. The first hour or two of clothes drying is particularly critical for moisture emission. Indoor laundry drying: Full-scale determination of water emission rate and impact on thermal comfort https://doi.org/10.1016/j.indenv.2025.100089 The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The One Take Format and the Mundane Routine of Laundry 00:00:58 The Energy Paradox: Why We're Told to Ditch the Tumble Dryer 00:02:21 The Cotton Culprit: How Much Water Are We Really Releasing? 00:03:03 The Three Phases of Drying: From Burst to Exhaustion 00:04:04 The Endothermic Effect: Why Drying Clothes Literally Cools Your Room 00:04:40 The Thermal Comfort Crisis: When Laundry Drags You Out of the Comfort Zone 00:05:04 The Heating Trap: Trading Tumble Dryer Energy for Central Heating 00:05:26 The Strategic Solution: Building Physics Meets Laundry Day 00:06:01 Closing Thoughts: Treating Mundane Tasks with Building Physics Respect

This week, we sit down with Rachel Hodgdon, President and CEO of the International WELL Building Institute (IWBI), to explore a question that fundamentally challenges how we think about healthy buildings: What if the single biggest barrier to transforming the built environment isn't our lack of knowledge about indoor environmental quality—but our inability to communicate complexity in ways that inspire action rather than paralysis? Key Topics Discussed: - Meeting People Where They Are: How do you communicate the holistic vision of indoor environmental quality without overwhelming stakeholders? Rachel explains why IWBI always starts with what matters most to the person across the table. If you're talking to a CEO, lead with recruitment, retention, and productivity. If you're talking to a facilities manager, talk about deferred maintenance and occupant satisfaction. - Incremental Progress Over Perfection: Unlike many certifications that reward only finished projects, WELL is designed to celebrate incremental progress. WELL at Scale has proven that clients don't move in straight lines. They might start with one landmark building, then progress toward equity ratings across portfolios, or spend a year focusing on just a few features. One point earned toward any designation now counts toward full certification. - Performance Testing Reveals the Invisible: WELL is proudly performance based. After a project is complete and occupied, third party testers measure air quality, water quality, thermal comfort, lighting, and sound. Buildings that fail must retest. Rachel shares stories of projects that discovered elevator shafts pumping unfiltered air into lobbies, printers off gassing VOCs, and contaminated soil beneath indoor plants. Without performance testing, these issues would never have been found. - Residential and Affordable Housing: WELL for Residential launched as a pilot expecting 3,000 enrollments. It received 30,000 straight out of the gate, including 22,000 military homes. Rachel highlights a groundbreaking partnership with Enterprise Community Partners, embedding WELL into the Enterprise Green Communities standard for affordable housing. This means WELL is now legislated in over 50 percent of US states for affordable housing, ensuring the people most in need benefit first, not last. GUEST: Rachel Hodgdon President and CEO, International WELL Building Institute https://www.linkedin.com/in/rachelhodgdon/ IWBI https://www.wellcertified.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Meeting Rachel Hodgdon and the IWBI Mission 00:02:50 The Complexity Challenge: Communicating Holistic Indoor Environmental Quality 00:03:53 One WELL: Simplifying Entry Points and Rewarding Incremental Progress 00:07:59 The Apple Approach: Building a Unified Ecosystem for Healthy Buildings 00:09:40 Evolution from Green Buildings: The Second Wave of Sustainability 00:12:29 Authority and Accessibility: Balancing Technical Rigor with Broad Appeal 00:21:37 Meeting People Where They Are: The Art of Advocacy and Communication 00:31:47 The Power of Experience: Case Studies and Exemplar Spaces 00:36:05 Beyond Headquarters: Reaching the Long Tail of the Built Environment 00:39:27 WELL at Scale and Existing Buildings: Flexibility for Portfolios 00:40:58 Military Housing and Affordable Housing: 30,000 Homes and Counting 00:55:56 The Australian Success Story: What's Happening Down Under 00:58:54 Navigating Headwinds: DEI, Sustainability, and the Great Rebrand 01:05:05 Performance Testing and Accountability: Making the Invisible Visible 01:23:23 The ROI of Healthy Buildings: Retention, Recruitment, and Productivity 01:20:48 Neurodiversity and Universal Design: Designing for the Extremes Benefits Everyone 01:42:45 The Medical Gap: Why Doctors Don't Ask About Your Home 01:47:15 The Future: Continuous Monitoring and the Next Ten Years 01:50:33 Closing Thoughts: Data is Knowledge, Knowledge is Power

This week, we dive into a fascinating paper from Douglas Booker published in the journal Athermira titled Unstable Air: How COVID-19 Remade Knowing Air Quality in School Classrooms, to explore a question that fundamentally challenges how we think about indoor air quality intervention: What if the single most important lesson from the pandemic isn't that we need to measure air quality—but that we need to fundamentally rethink who is responsible for fixing it, and whether our solutions are creating entirely new problems? This paper offers a rare behind the scenes look at an applied indoor air quality research project that got completely hijacked and subsequently reshaped by the global pandemic. It examines how our understanding of what makes air good or bad is not just a scientific fact but something that shifts based on society, politics, and in this case, a novel virus. Key Topics Discussed: The Original Mission: Before COVID, researchers deployed sophisticated air quality monitors into 20 school classrooms across England and Wales to measure traditional pollutants—ultrafine particles, nitrogen dioxide, VOCs—things infiltrating from outside or off-gassing from furniture. The goal was straightforward: measure the bad stuff and see how effectively air cleaners could scrub it away. The Pandemic Pivot: When COVID hit, the entire narrative flipped. Suddenly the greatest source of indoor air pollution wasn't traffic or cleaning products—it was human breathing. We became the source of contamination. The project had to adapt, but hit a microscopic hurdle: how do you actually measure a virus in the air when your monitors just count particles without telling you what they are? The Carbon Dioxide Proxy: Unable to isolate viral particles, researchers pivoted to a reliable proxy: carbon dioxide. By watching CO2 levels rise and fall, they could measure how much air in the room had already been in someone else's lungs and calculate ventilation rates. Pre-COVID data showed classrooms regularly exceeded recommended limits. But graphs alone don't change behaviour. The Wells Riley Translation: To translate numbers into risk, researchers used the Wells Riley equation to calculate airborne infection probability. The results were powerful: in one scenario, low ventilation created an 80% probability of infection. Simply increasing airflow to 100 cubic metres per hour dropped that to 40%. Small ventilation improvements created massive risk reductions. The Milk Out of Your Tea Problem: In the rush to dilute the virus by opening windows, we might be trading one severe health risk for another. If your school sits on a busy urban road, opening windows drops CO2 and virus risk but floods classrooms with toxic traffic fumes. Running a portable air cleaner with windows wide open to a polluted street is like trying to take milk out of your tea. The Inequality of Personal Responsibility: By handing out CO2 monitors and telling teachers to manage windows, the government effectively individualised air quality. The message: here's a blinking light, fixing it is your responsibility. Unstable air: How COVID-19 remade knowing air quality in school classrooms https://www.researchgate.net/publication/378714580_Unstable_air_How_COVID-19_remade_knowing_air_quality_in_school_classrooms The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The One Take Format and Unstable Air 00:01:27 The Outdoor Air Quality Paradox: Why We Ignored Indoor Spaces 00:02:30 The Original Mission: Measuring Classroom Pollutants in 2020 00:03:18 The Pandemic Pivot: When Humans Became the Pollution Source 00:03:58 The Measurement Problem: You Can't See a Virus in Particle Counts 00:04:33 The CO2 Proxy Solution: 150 Years of Measuring Bad Air 00:05:57 The Wells-Riley Equation: Translating Numbers Into Infection Risk 00:07:18 From Concern to Care: The Ethical Intervention That Worked 00:08:25 The Window Paradox: Trading Viral Risk for Toxic Fumes 00:09:35 The Inequality Problem: When Air Quality Becomes Personal Responsibility 00:10:23 The Critical Future: Building Better Pandemic Infrastructure

This week, we sit down with Christopher Mueller, Global Director of the High Purity Segment at AAF International (American Air Filters), to explore a question that fundamentally challenges how we think about indoor air quality: What if the single biggest gap in our approach to healthy buildings isn't particulate filtration—but our complete failure to address the invisible chemical soup we're breathing every single day? Chris brings over 40 years of deep expertise in environmental air quality and gas phase air filtration. With more than 200 peer reviewed papers, hundreds of seminars, and co authorship of major industry handbooks including the NAFSA Air Filtration Handbook and ASHRAE standards, Chris has testified at OSHA on indoor air quality standards and consulted with governments worldwide. He is the former chair of ASHRAE 145, which developed the first standard for assessing gas phase air filtration media performance, and remains a member of key technical committees shaping the future of air cleaning globally. Key Topics Discussed: The Fundamental Difference: Particulate filtration is catching. Gas phase filtration is reacting. Gases move by diffusion, from high to low concentration, and removing them requires adsorption—getting molecules out of the air and onto the surface of materials like activated carbon, alumina, or zeolites. Unlike particle filters, gas phase filters don't fill up. They run out. They lose effectiveness over time, and there's no pressure gauge to tell you when. Surface Area Is Everything: Most activated carbons have around 1100 square meters per gram of surface area. That's not the exterior of the pellet. That's the interior pore structure. Volatile organic compounds get inside, condense back into liquid form, and stay there. The physics of adsorption depend on molecular weight, concentration, residence time, and contact efficiency. You need the air to touch the adsorbent before it exits the filter. One Filter Won't Do It All: You can't use one type of gas phase media to remove everything. Basic activated carbon handles many organic compounds. Acid gases like sulfur dioxide require chemically treated carbon. Ammonia requires another type entirely. Think of it like particulate filtration: pre filter, intermediate filter, final filter. Same logic applies to chemicals. The Four Global Markets: Corrosion control accounts for 60 to 65 percent of the global gas phase filtration market, driven by electronics manufacturing, data centers, and industrial facilities where chemical contamination voids equipment warranties. Wastewater odor control is second. Indoor air quality in commercial buildings is third. Airborne molecular contamination in semiconductor manufacturing is fourth. The total global market is approximately $2 billion and growing at 5.5 percent annually. GUEST: Christopher Mueller Global Director, High Purity Segment, AAF International https://www.linkedin.com/in/chrismullerconsulting/ AAF International https://www.aafintl.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Meeting the Gas Phase Air Cleaning Guru 00:02:51 The Fundamental Difference: Particulate vs Gas Phase Filtration 00:09:29 The Science of Adsorption: How Gas Phase Filters Actually Work 00:17:10 The Swiss Cheese Approach: Multi-Stage Gas Phase Filtration 00:23:20 Form Factors and Physical Products: From Pleats to Packed Beds 00:28:00 Precision and Specificity: Can You Target Individual Chemicals? 00:34:20 The Four Markets: Where Gas Phase Filtration Is Applied Today 00:38:24 Corrosion Control: The Hidden Giant of Gas Phase Filtration 00:44:00 Indoor Air Quality and the IAQP Opportunity 00:48:38 The Commercial Reality: Why Gas Phase Is Still a Hard Sell 01:13:49 Materials and Sustainability: What Is Activated Carbon Made From? 01:24:13 The Path Forward: Education, Standards, and Market Evolution 01:36:35 Closing Thoughts: Making the Invisible Visible

This week, we dive into a groundbreaking computational fluid dynamics study from KTH Royal Institute of Technology in Sweden that fundamentally challenges how we think about portable air cleaners in care homes: What if the single most important decision about air cleaning isn't which device you buy—but where you put it in the room? During the height of the COVID-19 pandemic, care homes experienced devastating mortality rates among elderly residents. These environments are uniquely challenging—combining elements of healthcare facilities with residential living spaces, housing vulnerable populations who spend prolonged periods indoors with limited mobility and compromised immune systems. Portable air cleaners emerged as a promising, accessible solution. But does it actually matter where you place them? Can you just plug them in wherever the cable reaches and assume the job is done? And critically, will the airflow create cold drafts that make elderly residents so uncomfortable they simply switch the device off? Key Topics Discussed: The Care Home Challenge: Why care homes represent such a unique built environment challenge. Vulnerable populations with reduced mobility, chronic illnesses, compromised thermoregulation making them sensitive to drafts, and prolonged indoor exposure without control over their immediate environment. Any intervention has to work within these constraints. The 74% Variation Problem: Using computational fluid dynamics simulations, researchers tested the same portable air cleaner in nine different locations within a typical care home room. The result: placement alone created a 74% variation in infection risk. Same machine, same room, same people—completely different outcomes based purely on where the device sat. The Worst Case Scenario: In one placement configuration, positioning the air cleaner near the infected healthcare worker created a powerful airflow jet that actively transported exhaled virus particles directly into the breathing zone of the elderly patient. The infection risk skyrocketed to 85.9%. The air cleaner didn't just fail—it made things dramatically worse. The Best Case Scenario: Placing the air cleaner in the centre of the room created the lowest infection risk—75 to 86% reduction compared to no air cleaner—by forming an invisible air barrier between occupants. But it's completely impractical due to tripping hazards in environments with wheelchairs, walking frames, and elderly residents with limited mobility. The Thermal Comfort Win: Across all tested scenarios, draft rates remained below the 10% discomfort threshold. This is critical. There's no point achieving perfect air quality if the occupant is freezing cold and turns the device off. The study proves portable air cleaners can reduce infection risk without compromising thermal comfort—if used correctly. The Training Gap: The on demand, plug and play nature of portable air cleaners means frontline workers—nurses, cleaners, facility managers—play a critical role in their effectiveness. Without proper training and clear visual guidance showing safe placement zones, we risk unintended consequences. Procurement isn't enough. Education is essential. CFD study on performance of portable air cleaner on infection risk and draught rate in care homes https://doi.org/10.1016/j.indenv.2026.100151 The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Lindab (https://www.lindab.ie/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) - Farmwood (https://farmwood.co.uk/) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The One Take Format and This Week's CFD Study 00:01:03 The Care Home Crisis: Why COVID-19 Hit the Elderly So Hard 00:01:37 The Vulnerable Population: Mobility, Immunity, and Thermal Sensitivity 00:02:09 The Portable Air Cleaner Promise: Easy Solution or Placement Problem? 00:02:50 The CFD Simulation: Mapping Invisible Airflow and Virus Particles 00:03:43 The Good News: 75-86% Risk Reduction Without Creating Drafts 00:04:26 The Shocking Discovery: 74% Variation Based on Placement Alone 00:04:58 The Worst Case Scenario: When Air Cleaners Blow Virus Directly at Patients 00:05:45 The Best Placement Dilemma: Center of Room vs Practical Safety 00:06:47 The Real World Lesson: Education, Training, and Strategic Deployment

This week, we sit down with Mikael Börjesson, Future Solutions and Public Affairs Director at Swegon Group, to explore a question that fundamentally challenges how we think about sustainability in the HVAC industry: What if the biggest transformation in ventilation isn't about technology or performance anymore—but about fundamentally rethinking how we manufacture, install, use, and reuse the systems that keep our buildings breathing? Mikael works at the intersection of innovation, sustainability, and public policy, with deep roots in the sector and vast experience in stakeholder engagement, industry collaboration, and EU regulatory frameworks. He brings a rare perspective—someone who sees both the internal pressures on manufacturers to decarbonize their supply chains and the external pressures from investors, policymakers, and end users demanding transparency, circularity, and accountability. Key Topics Discussed: The Two Wallets Problem: How sustainability has moved from a marketing exercise to a genuine accounting challenge. There's the traditional wallet—cost, performance, energy efficiency. And now there's the sustainability wallet—embodied carbon, circularity, material choices. Both need to be satisfied, and they don't always align. Embodied Carbon is the New Battleground: In renovations, HVAC installations can represent 40 to 60 percent of the total carbon footprint of a project. Suddenly, ventilation manufacturers are no longer a marginal cost—they're a major driver of sustainability outcomes. That changes the conversation entirely. Circularity is Here—And It's Real: Swegon has already completed its first fully circular project—air handling units, diffusers, and dampers refurbished, remanufactured, and reinstalled alongside new low-carbon components. No extra cost. No performance compromise. Just a fundamentally different way of doing business. The Stakeholder Chain is Broken: The traditional construction supply chain—investor, designer, installer, service technician—is built for linear consumption. Circularity requires a completely different model, with new roles, new relationships, and new risks. Some stakeholders will become obsolete. Others will emerge. The transition is messy. The Harmonization Problem: Environmental Product Declarations are becoming the standard way to communicate embodied carbon. But they're calculated differently across different standards, different product categories, different regions. The result: you can't compare products. The industry needs harmonization urgently GUEST: Mikael Börjesson Future Solutions and Public Affairs Director, Swegon Group https://www.linkedin.com/in/mikael-b%C3%B6rjesson/ https://www.swegon.com/ https://www.swegonairacademy.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Lindab (https://www.lindab.ie/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Meeting Mikael Bowieson from Swegon Group 00:02:23 The Sustainability Evolution: From Energy Efficiency to Embodied Carbon 00:11:52 The Two Wallet Problem: Balancing Cost and Carbon 00:14:20 Having Difficult Conversations: When Sustainability Meets the Supply Chain 00:19:39 The Consumption Paradox: Growth vs Sustainability 00:26:28 Scope Emissions and the Middle of the Supply Chain 00:30:02 The Circular Economy Journey: Reuse, Remanufacture, and New Business Models 00:39:12 The Real Project: Circular HVAC in a Swedish School 00:41:00 Breaking the Chain: What It Takes to Scale Circular Business Models 00:44:00 The Carrot and the Stick: Policy, Incentives, and Market Drivers 00:46:12 Renovation Reality: Where HVAC Becomes 40 to 60 Percent of Carbon Impact 00:33:12 The Harmonization Problem: Making EPDs Comparable 01:13:32 Future Solutions and Public Affairs: A Dual Role Explained 01:17:21 Innovation Hunting: Finding the Next Generation of HVAC Solutions 01:27:47 The Interoperability Challenge: Making Complex Building Systems Work Together 01:31:18 Learning from Cars: Why Buildings Need Self-Diagnosing Systems 01:02:37 The Indoor Air Quality Awareness Gap: Why We Track Outdoor but Ignore Indoor 01:09:46 The Public Health Case: Indoor Air Quality Equals Smoking in Health Impact 01:11:48 The Investment Problem: Who Benefits vs Who Pays 01:41:53 The Weakest Link Paradox: When the Strongest Part of the Chain Holds Back Progress

This week, we sit down with Ben Jones, Associate Professor at the University of Nottingham and one of the lead authors of AM10, CIBSE's guide to natural ventilation in non-domestic buildings, to explore a question that fundamentally challenges how we think about ventilation strategy: What if the oldest approach to ventilation—natural airflow—still has a critical role to play in some of the most advanced buildings we're designing today, and what if we've been making the same mistakes for decades because we never really understood the fundamentals? After a decade in development, AM10 has been completely rewritten for 2026—not just to update the maths, but to make natural ventilation accessible, understandable, and practical for everyone from salespeople to architects to engineers who need to know whether natural ventilation is even feasible for their project before they waste time and money chasing the wrong solution. Key Topics Discussed: Why AM10 Needed Rewriting: The 2005 version was intimidating, dense, and assumed too much prior knowledge. The 2026 version is structured in layers—chapter two is designed so that anyone, from a student to a salesperson, can understand the basic physics. If you want the deep maths, it's there. If you just need to know whether natural ventilation will work for your building, you can get that answer quickly. The Physics Made Simple: Warm air rises. Pressure differences drive flow. Wind complicates everything. But somewhere on every facade, there's a neutral pressure level where the sign flips—where air stops coming in and starts going out. Controlling that point is the essence of natural ventilation design. Get it wrong, and your building doesn't breathe. Effective Area vs Free Area: One of the biggest changes in AM10 is how openings are measured. Combining free area with discharge coefficients into a single effective area metric forces window manufacturers to actually test their products aerodynamically and gives engineers a real number they can design with. No more fudging the geometry. Single-Sided Ventilation Gets Smarter: The old equations were too simplistic. The new version accounts for recirculation zones in large openings—where air comes in at the bottom, goes out at the top, and mixes in the middle. It accounts for wind-driven turbulent mixing. The result: better-sized openings that won't leave buildings overheating in summer GUEST: Ben Jones Associate Professor, University of Nottingham | Lead Author, CIBSE AM10 https://www.linkedin.com/in/benjamin-jones-0686a214/ CIBSE AM10: Natural Ventilation in Non-Domestic Buildings https://www.cibse.org/knowledge-research/knowledge-portal/am10-natural-ventilation-in-non-domestic-buildings-2026-pdf/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Lindab (https://www.lindab.ie/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Return of Air Quality Matters 00:02:14 The Genesis of AM10: A 20-Year Evolution 00:06:03 From PhD to Practice: Ben's Natural Ventilation Journey 00:08:34 The Philosophy Behind AM10: Making Physics Accessible 00:10:14 Why Ventilate: Sizing for Summer, Surviving Winter 00:11:19 The Physics of Buoyancy: When Hot Air Actually Rises 00:13:09 When Design Meets Reality: The Complexity Challenge 00:14:41 The Feasibility Question: Is Natural Ventilation Right for Your Building? 00:15:48 The Neutral Pressure Level: Where Physics Flips Sign 00:16:50 Wind's Wild Card: Adding Complexity to Buoyancy 00:18:44 The Case for Natural Ventilation: Energy, Carbon, and Human Connection 00:19:17 The Adaptive Comfort Advantage: When Control Matters More Than Precision 00:23:19 Natural Ventilation Through the Ages: Ancient Wisdom Meets Modern Buildings 00:31:59 The Outdoor Air Reality: When Fresh Air Isn't Fresh 00:42:15 The Great Automation Failure: 3200 PPM in London's Smartest Building 00:35:04 What Changed in 2026: New Physics and Effective Area 00:39:25 From Spreadsheets to Software: How AM10 Gets Used 00:40:40 Designed for Everyone: Who Should Read AM10 00:42:40 The Sensor Revolution: Transparency in Natural Ventilation Performance 00:54:26 Hot Climate Solutions: Thermal Mass and Ancient Technologies 00:55:47 The Fundamental Design Principle: Natural Ventilation from Day One 00:56:43 Getting Your Hands on AM10: Access, Training, and the Future

This week, we sit down with Danny Ashton, founder and host of HouseFresh, a consumer comparisons and testing YouTube channel and website for residential air cleaners, to explore a question that fundamentally challenges how we buy, trust, and understand indoor air quality technology: What if the air cleaner market is deliberately designed to confuse you—and what if the only way to cut through the noise is to test everything, measure what matters, and refuse to play the game? Danny brings a rare combination of technical rigour, marketing insight, and consumer advocacy to a sector that desperately needs it. Since 2020, he has tested over 130 air cleaners in real-world conditions, measuring particulate removal performance, sound levels, energy consumption, and filter costs—creating one of the most valuable independent resources available to consumers today. Key Topics Discussed: The 2020 Fog of War: What it was like looking out at the air cleaner landscape during the pandemic. A marketplace flooded with products from every corner of the planet, tested in different ways, presenting benefits in wildly inconsistent formats. An unbelievable minefield for consumers desperate to protect their families. The Invisible Product Problem: Why air cleaners are uniquely vulnerable to being sold poorly. You can tell if an air fryer doesn't work. You can't see particulate matter. A product could be absolutely rubbish and you'd have no idea. That opens the door for companies to sell what sells, not what works. The Affiliate Revenue Trap: How the entire online ecosystem is rigged around pushing products that pay the highest commissions, not the ones that perform best. Some models offer 40 to 50 percent affiliate cuts versus 2 or 3 percent for others. The incentive structure is broken, and consumers pay the price. What Actually Matters: Performance at quiet fan speeds, not just top speed. Energy consumption over time. Filter replacement costs. Sound quality, not just decibel ratings. The ability to turn off ionizers, UV lights, and other additive technologies. The fundamentals that marketing doesn't want you to focus on. The PC Fan Revolution: Why DIY air cleaners built with computer fans and standard filters consistently outperform expensive retail units on performance, noise, and cost. Clean Air Kits, New Care, Nukit—small teams delivering serious engineering without the marketing budget or the proprietary filter lock-in. The Carbon Filter Lie: How thin fabric carbon layers smell sweet for a few weeks and then fail completely, triggering consumers to replace entire filter assemblies. Meanwhile, thick bonded carbon filters can last significantly longer—but they cost more and don't drive repeat sales as aggressively. GUEST: Danny Ashton Founder and Host, HouseFresh Danny Ashton LinkedIn - https://www.linkedin.com/in/dannyashton/ https://housefresh.com/ https://www.youtube.com/@HouseFresh The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Lindab (https://www.lindab.ie/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Invisible Problem with Air Purifiers 00:02:41 The Fog of War: Air Quality During the Pandemic 00:03:18 Learning from the Past: The 2010s Air Purifier Landscape 00:06:06 The Bamboozle Business: How Confusion Sells Products 00:08:07 The Testing Philosophy: Benchmarking What Actually Matters 00:09:37 The Sound and the Fury: Why Quiet Performance Matters Most 00:12:03 The Amazon Hellscape: Peak Online Shopping Meets Air Quality 00:13:38 The Air Fryer Test: Why Air Purifiers Are Uniquely Deceptive 00:29:23 The Great Filter Debate: HEPA Hype vs Real World Performance 00:27:12 The PC Fan Revolution: When Computer Nerds Met Air Quality 00:34:24 The Razor Blade Business Model: Filters as Recurring Revenue 00:37:26 The Size Problem: Why Bigger Really Is Better 00:54:30 The Sensor Gimmick or Game Changer Question 01:07:05 The Carbon Conundrum: When Filters Fight Odors and Lose 01:16:42 The Additive Air Cleaner Minefield: Ionizers, UV, and Chemistry 01:27:06 The Testing Reality: 133 Units and Counting 01:44:22 The YouTube Education Effect: Maturing the Consumer Market 01:37:25 The Future: Matter Protocol and Smart Home Integration 01:50:06 The Mission: Raising the Bar in a Rigged Market

This week, we step slightly outside the building envelope to examine a question that fundamentally challenges everything we think we know about air pollution: What if the metric the entire world uses to measure air quality is structurally blind to the most dangerous particles we breathe? The document is a perspective piece published in the Bulletin of the World Health Organization, titled Air Quality Standards and WHO Guidance on Particulate Matter Measurement 2.5 Microns. It represents a profound wake-up call for the global air quality community, arguing that PM 2.5—the gold standard metric used worldwide to regulate, monitor, and discuss particulate air pollution—has serious fundamental blind spots that could be undermining decades of public health policy. The World Health Organization's normative guidance on ambient air quality is fundamentally based on evidence from health and exposure studies regarding the harms associated with mass concentrations of airborne particulate matter expressed as PM 2.5. These WHO guidelines are a critical reference point for jurisdictions all over the planet when developing or revising their own ambient air quality standards. But this paper makes a stark argument: our global gold standard is missing the full scope of health-harming particulate air pollution. Key Topics Discussed: The Harmonization Problem: The current WHO guidance does not cover harmonization of averaging methods for concentrations measured during data aggregation, nor does it cover how to handle exceedances of PM 2.5 levels. Variations in how different countries measure and aggregate data can obscure true ambient air pollution levels—comparing apples with oranges on a global scale. The Mass-Based Metric is Fundamentally Flawed: PM 2.5 is a mass-based metric. It simply weighs the dust. It completely fails to consider the physicochemical characteristics of airborne particles—their specific size, chemical composition, bioavailability of potentially harmful elements, and critically, the particle number concentrations of different sized particles, including ultrafine particles. The Bowling Ball vs. Marbles Problem: Imagine a box. A single bowling ball gives you a high weight reading. But what if that box is filled with tens of thousands of marbles? The mass of PM 2.5 comes mostly from larger fine particles. The mass of ultrafine particles is negligible when compared to bigger particles. However, the vast majority of particles in typical ambient environments are ultrafine particles—defined as being less than 0.1 microns. A city could hit its WHO mass targets by removing a few heavy bowling balls but leave tens of thousands of smaller marbles floating around. The 5 Microgram Threshold: When PM 2.5 is higher than 5 micrograms per cubic meter, the mass concentration does not correlate well with the particle number of ultrafine particles. Therefore, control measures that aim to reduce high PM 2.5 levels might not actually reduce the ultrafine particle count at all. A good correlation does exist below 5 micrograms per cubic meter, but as the authors bluntly state, most countries are far from achieving such low ambient air pollution. Why Ultrafine Particles Are So Dangerous: Because they are so small, they don't just get stuck in your throat or upper airways—they go deep. Short-term exposure is associated with respiratory symptoms and systemic inflammation, affecting your heart and blood pressure. Long-term exposure is associated with increased mortality, especially cardiovascular and lung-related mortality, as well as ischemic heart disease. Air Quality Standards and WHO Guidance on Particulate Matter Measurement 2.5 Microns Bulletin of the World Health Organization 10.2471/BLT.23.290522 (https://doi.org/10.2471/BLT.23.290522) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Blind Spot in Our Global Air Quality Standard 00:01:49 The Structural Problem: Missing Harmonization in WHO Guidance 00:02:45 The Fundamental Flaw: Why Mass-Based Metrics Miss the Point 00:03:49 The Bowling Ball vs Marbles Problem: Understanding Particle Count 00:05:14 The Five Microgram Threshold: Where Mass and Number Diverge 00:06:18 The Health Threat: Why Ultrafine Particles Are So Dangerous 00:07:13 The Solution: Introducing PM 2.5 Number Density Metric 00:08:33 The Practical Challenges: Monitoring Ultrafine Particles in the Real World 00:09:32 The Indoor Air Quality Wake-Up Call: What Your Monitors Are Missing 00:11:20 The Path Forward: Harmonizing Global Standards for Real Protection

This week, we sit down with Jason Jones, Director of Air Quality Management at Fellowes, to explore a question that fundamentally challenges how we sell, specify, and sustain indoor air quality solutions in the real world: What if the biggest barrier to clean indoor air isn't technology or science—but the economic conversation we're having with the people who actually have to write the cheques? Jason leads Fellowes' sales and marketing efforts in the air quality space, working closely with distributors, sales representatives, and end users to help them understand the role of smart, responsive air quality management. This is a theory into practice conversation, and it's critically important. We can discuss the impacts of air quality on health, wellbeing, performance, and energy all day long—but at some point, someone, somewhere, has to literally buy into the idea. Jason provides a fascinating window into how a respected player in the sector, delivering products that actually improve air quality, frames the problem and the solutions, how those conversations are going, and where they think this sector is heading next. Key Topics Discussed: Post-Pandemic Reality: How air quality awareness has evolved since COVID. Some people internalized the lesson and carried it forward into the environments they work in. Others were willing to just get back to normal. The perception problem: if it doesn't smell bad, chances are the air must be clean. But we don't get to control the air we breathe in most of the spaces we're in. Where the Traction Is: Healthcare, education, K-12, higher ed, and assisted living facilities are where air quality is sticking most. The generation that missed prom because of the pandemic took that lesson forward into their lives. That's why there's a bright future for air quality—it made an indelible mark on that generation. Leaning Into Energy Savings: Why Fellowes is talking more and more about energy savings and using standards like ASHRAE's Indoor Air Quality Procedure to specify air purification alongside HVAC systems. The goal: reach the same or better air quality while reducing outside air reliance. Clean air is a human right, but the reality is that building owners have bills to pay and balance sheets to worry about. VRP vs IAQP—A 101: Ventilation Rate Procedure is the blunt instrument—prescriptive ventilation rates based on building type and occupancy. Indoor Air Quality Procedure is more sophisticated—designing around specific contaminants of concern, factoring in air purification and filtration, and allowing you to reduce outside air by 30, 40, 50 percent or more. Less outside air means less heating and cooling, smaller HVAC systems, and potential first cost savings. The Education Experiment: Schools are a massive data set. With thousands of classrooms being phased into air quality solutions over time, we'll finally be able to see clear trends in absenteeism rates, teacher sick days, and student test scores. You can't learn if you're not in class. It's that simple. And it's the most black and white metric of them all. GUEST: Jason Jones https://www.linkedin.com/in/jason-jones-0aa672b/ Director of Air Quality Management, Fellowes Fellowes https://www.fellowes.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Commercial Reality of Indoor Air Quality 00:03:11 Post-Pandemic Reality: Who Still Cares About Air Quality? 00:08:09 The Budget Battle: Nice to Have vs Need to Have 00:10:05 The Energy Efficiency Angle: A New Way to Sell Clean Air 00:26:00 VRP vs IAQP: Two Approaches to Building Ventilation 00:24:47 The HVAC Energy Equation: Why Outside Air Is So Expensive 00:34:18 The Complexity Challenge: Is the Industry Ready for IAQP? 00:37:51 The Subjective Element: Why Human Perception Still Matters 01:25:09 The Fellows Ecosystem: Networked Air Quality Management 01:16:44 Education as the Testing Ground: The Data Goldmine 01:41:28 The AI Revolution: Natural Language Control of Building Systems

This week, we examine a document that represents a profound shift in how we think about school environments: What if the debate over airborne transmission and clean air in schools is finally over—and the real fight is just beginning? The document is titled Ventilation and Air Quality in Education and Childcare Settings, published on 24 February 2026 by the UK Department for Education. It applies specifically to England, and it codifies into official government guidance something we've been arguing about for years: that good ventilation is absolutely essential for healthy and productive learning environments. This isn't a theoretical discussion anymore. This is operational policy. The guidance plainly states that effective ventilation does more than just prevent overheating. It improves pupils' alertness and concentration. It removes polluted air. And crucially, it removes air that might contain virus particles, reducing the spread of respiratory infections like colds, flu, and COVID-19. This is massive. It places the management of indoor air quality squarely in the realm of basic school health and safety. Key Topics Discussed: The Monitoring Framework: Schools are expected to regularly monitor CO2 concentrations across their buildings. The guidance provides best practices on sensor placement—at head height or table height, at least half a meter away from people, and away from doors, windows, or ventilation outlets. If you're under 800 ppm, your ventilation is good. Between 800 and 1500 ppm, it's adequate but could be improved. Over 1500 ppm, your ventilation is officially poor and you need to act. Pragmatic Winter Compromises: The guidance addresses the real-world conflict between keeping kids warm and keeping their air clean. Partially open windows, open higher-level windows to reduce drafts, air out rooms for 10 minutes every hour during breaks. But crucially, do not prop fire doors open to get cross ventilation. Beyond CO2: The document talks about multifunctional environmental sensors that can track temperature, humidity, particulate matter like PM2.5 and PM10, and volatile organic compounds from sources like formaldehyde, cleaning chemicals, body odors, and vaping products. Yes, they specifically mention monitoring for vapes. Air Cleaning Units—With Massive Caveats: The Department for Education is crystal clear that while air cleaning units reduce airborne contaminants including viruses, bacteria, and fungal spores, they do absolutely nothing to improve ventilation or lower CO2 levels. They are not a substitute for ventilation. The government only recommends HEPA filtration units—subtractive technology that physically catches pollutants. They explicitly reject air ionizers, ozone generators, and units with unenclosed UV fields. The Funding Sting: Between 2021 and 2023, the Department for Education provided CO2 monitors and air cleaning units to all state-funded education settings. But now, in 2026, the guidance explicitly states that the government will not replace faulty or damaged devices, and they will not pay for replacement filters. The ongoing financial burden of maintaining clean air has been shifted entirely onto individual school budgets. The Controversial Bits: The guidance talks about bringing in fresh outdoor air—a phrase doing a lot of heavy lifting when many schools are backed up against busy roads. It standardizes on NDIR CO2 sensors, which are solid but arguably already behind the times compared to photoacoustic sensors. And that 1500 ppm threshold—many in our community will argue that allowing CO2 levels anywhere near 1500 ppm is simply not acceptable for vulnerable populations. Ventilation and Air Quality in Education and Childcare Settings UK Department for Education, 24 February 2026 https://www.gov.uk/government/publications/ventilation-and-air-quality-in-education-and-childcare-settings/ventilation-and-air-quality-in-education-and-childcare-settings The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The UK's New School Air Quality Guidance 00:01:15 The Science Is Settled: Air Quality as Basic Health and Safety 00:02:16 The Monitoring Solution: CO2 as Your Ventilation Indicator 00:03:19 The Traffic Light System: Understanding CO2 Thresholds 00:04:03 Winter Pragmatism: Balancing Warmth and Fresh Air 00:04:46 Beyond CO2: Multifunctional Environmental Sensors 00:05:36 Air Cleaning Units: The Promise and the Limitations 00:06:39 HEPA Only: The Government's Firm Stance on Technology 00:07:41 The Sting in the Tail: Who Pays for Ongoing Maintenance 00:08:56 The Uncomfortable Details: Fresh Air, NDIR, and 1500 PPM 00:10:41 The Bottom Line: Science Won, Now the Funding Battle Begins

This week, we sit down with Stephanie Taylor, a unique physician architect whose career is dedicated to bridging the deep chasm between the medical profession and the built environment, to explore a question that fundamentally challenges how we think about buildings: What if the real problem isn't just that our buildings are failing us—but that we're measuring the wrong things entirely? As medical advisor for ThinkLite Air, she applies her clinical insights to the development of advanced air sensing and cleaning technology, transforming raw environmental data into actionable health impact scores. By integrating medical science into engineering standards, she continues to champion the idea that engineers are in many ways the physicians of the future, responsible for the preventative care of billions of people who spend so much of their time indoors. Key Topics Discussed: Buildings as Extensions of Health: Why treating buildings as part of caring for human health could be one of the biggest advances of our century. The opportunities are clear: decreased acute and chronic diseases, improved productivity, better financial outcomes. But will we actually do it? The obstacles include resistance to change, difficulty bringing the medical community into building management, and the legal ramifications of talking about health. Defining the Finish Line: What does good indoor environmental health actually look like? Stephanie's answer: an indoor space that does not increase our physiological stress level. Not just measuring hazards, but diminishing components of the indoor environment that cause stress on our cardiovascular, respiratory, neurological, and immune systems. The Imperceptible Forces Problem: We design buildings and respond to environments as we can perceive them—rain, cold, visible mould. But the imperceptible exposures are the ones causing us problems. Low humidity impairing immunity. Ultrafine particles penetrating deep into the lungs. VOCs we cannot smell. The challenge is monitoring and controlling what we cannot sense. The Platinum Building Paradox: Why even the most advanced buildings with all the badges can fail spectacularly. A healthy buildings conference held in a room where 100 experts sat in a fog of their own breath for four hours, CO2 climbing to 3,000 parts per million in one of the smartest buildings in London. The disconnect between design intent and operational reality. Beyond Wells Riley: Rethinking how we model risk. The traditional Wells Riley equation models exposure to infectious bioaerosols. Stephanie is expanding that framework to model not only exposure risk, but also what indoor air quality is doing to your immune system—your protective mechanisms. It's not just how many weapons are shooting at you, but your ability to defend yourself. ThinkLite and the Health Index: Seeing what's going on through sensors, analyzing the data in a way that is relevant for the human body system by system—lungs, brain, cardiovascular health—and then remediating. Turning arbitrary data points into relevant health metrics. Moving from zigzag lines on dashboards to actionable health impact scores GUEST: Stephanie Taylor Physician Architect | ASHRAE Fellow | Medical Advisor, ThinkLite Air Stephanie Taylor - LinkedIn https://www.linkedin.com/in/stephanie-taylor-md-b6456b8/ https://www.thinkliteair.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Buildings as an Extension of Human Health 00:06:42 The Medical-Building Disconnect: Why Healthcare Must Join the Conversation 00:12:17 Defining the Finish Line: What Does a Healthy Building Actually Look Like? 00:23:29 The Imperceptible Hazards: Why We Design for What We Can Sense 00:27:38 The Autonomic Building: Automation as an Extension of Human Physiology 00:33:27 The Platinum Building Paradox: When Award-Winning Spaces Fail Their Occupants 01:01:43 The Legal Minefield: Why Talking About Health Is Terrifying for Building Professionals 00:51:23 Think Light Air: Translating Environmental Data into Human Health Impact Scores 01:40:37 Beyond Wells-Riley: Modeling Vulnerability, Not Just Exposure 01:28:54 The Path Forward: Regulation, Education, and the Courage to Do the Hard Thing

This week, we tackle a question that cuts through decades of technical progress and scientific consensus: What if the reason we still don't have clean indoor air isn't because we lack the technology—but because we lack the policy to actually implement it? The paper is a policy commentary titled Federal and State Policy Opportunities to Improve Indoor Air Quality, published in the Journal of Health Security. It's authored by a powerhouse group of experts, including Georgia Lagoudas and colleagues from Brown University, Harvard, and several other leading institutions. Many of them have been previous guests on this podcast. This isn't a theoretical exercise. It's a roadmap—a practical, actionable menu of policy interventions that could finally bring indoor air quality into the same regulatory and public health framework that we've successfully built for drinking water, fire safety, and smoking bans. Here's the glaring truth: we spend about 90% of our time indoors, yet we have no unified national initiative for clean indoor air. We have the Clean Air Act. We have the EPA regulating outdoor air. But outdoor regulations completely fail to account for the fact that outdoor pollutants make their way inside—where we spend all our time—and they ignore the fact that indoor spaces have their own unique pollutant sources. Concentrations of certain pollutants can be two to five times higher indoors than outdoors. And outdoor regulations do absolutely nothing to address one of the biggest indoor threats: the spread of respiratory pathogens like COVID-19 and influenza. Key Topics Discussed: The Current Mess: The federal government doesn't really regulate indoor air outside of occupational settings, leaving jurisdiction to state and local governments. Building codes are adopted and enforced locally, creating a massive patchwork of different standards. Some states like California, Connecticut, and Minnesota have taken steps, especially for schools, but there's no comprehensive national roadmap. Develop Health-Based Indoor Air Quality Targets: Right now, building owners and facility managers don't have a simple unified goal. We need clear thresholds for easy-to-measure indicators like carbon dioxide and PM2.5. The EPA or a coalition of NGOs should publish voluntary health-based targets, providing a clear benchmark that states and local entities can adopt. If you don't know what the target is, you can't hit it. Support States and Local Communities to Adopt Standards: Develop a national model indoor air quality code—similar to national model energy codes. Provide tax incentives to commercial buildings that make indoor air quality improvements, similar to deductions for energy efficient buildings. Create a state playbook filled with template language for regulations and building codes to make it easy for local governments to take action. Implement Sector-Specific Standards: Schools need indoor air quality monitors, regular HVAC inspections, and better filtration. Nursing homes should have indoor air quality standards as a strict condition of participation, just like hospitals. Federal buildings housing around a million federal employees need robust ventilation verification programs. OSHA needs to update its permissible exposure limits—many were developed in the 1970s, nearly half a century ago. The Two Biggest Priorities: Developing health-based indoor air quality targets and getting states to adopt indoor air quality building standards. If we can agree on what good air looks like and put it into the building code, the market will innovate to meet those demands. Federal and State Policy Opportunities to Improve Indoor Air Quality 10.1177/23265094251410880 (https://doi.org/10.1177/23265094251410880) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Missing Framework for Clean Indoor Air 00:01:12 The Glaring Gap: Why Indoor Air Quality Has Been Ignored 00:01:45 Why Outdoor Regulations Fail Indoors 00:02:22 The Astronomical Cost of Inaction 00:03:01 The Current Mess: A Patchwork of Standards 00:03:55 Recommendation One: Health-Based Indoor Air Quality Targets 00:04:43 Recommendation Two: Supporting States with Standards and Financing 00:05:38 Recommendation Three: Sector-Specific Standards 00:07:13 Recommendation Four: Research and the Wild West of Air Purifiers 00:08:30 The Bottom Line: Clean Air Is a Choice We Must Make

This week, we sit down with Frank Kelly, Professor at Imperial College London and Director of the Environmental Research Group, to examine a question that fundamentally challenges how we think about air pollution: What if the real danger isn't just how much dust we're breathing, but what that dust is made of and what it does to our bodies at a cellular level? For over three decades, Frank Kelly has been one of the architects of London's modern understanding of air quality. His pioneering work on the oxidative potential of particulate matter has transformed how we evaluate the toxicity of everything from diesel exhaust to wood smoke. By proving how these pollutants trigger harmful free radical reactions and deplete antioxidants in the lungs, he provided the scientific backbone for London's most ambitious public health interventions, including the Congestion Charging Zone and Ultra Low Emissions Zone. Key Topics Discussed: Beyond Size and Mass: Why PM10, PM2.5, and ultrafine particles are categorized by size, but size alone doesn't tell us what's actually harmful. The real story is in the chemistry, the physics, and the biology of what those particles carry and what they do when they reach the lung. The Meteor Analogy: Particulate matter isn't just carbon spheres. It's a complex, ever-changing cocktail of metals, gases, chemicals, and biological material that picks up and sheds components as it moves through the environment and into our bodies. Oxidative Potential: What free radicals are, why transition metals on particle surfaces drive oxidative stress, and how the body's antioxidant defences like glutathione, vitamin C, and vitamin E fight back. When the balance tips, inflammation and cellular damage begin. The Seesaw Model: On one side, you have particulate pollution with oxidative potential. On the other, your body's natural defences. Your genetics, your diet, and your environment all determine where you sit on that seesaw and when the damage starts. The London Success Story: How Frank's research directly influenced the introduction of the Ultra Low Emissions Zone. The data showed that children living in East London exposed to heavy traffic pollution had slower lung growth than children outside London. That evidence became the catalyst for policy change. Indoor Air Quality and the Well Home Study: Over 100 homes in West London instrumented for two months each to understand indoor pollution sources. The findings: damp and mould in social housing, gas cooking as a major pollutant source, and pollution migrating from kitchens into children's bedrooms where it stayed trapped overnight. The Microplastics Problem: Modern tyres are 55% plastic. As the fossil fuel industry loses its market in surface transport, it's shifting to plastic production. Frank's team has developed methods to characterize plastic particles in air, water, and food. The challenge: distinguishing plastic signatures from human tissue in toxicology studies. The Future of Air Quality Monitoring: Moving beyond mass-based metrics to real-time oxidative potential monitoring. Frank's team is developing prototype instruments that measure free radical activity in the air instantaneously, allowing us to identify which pollution sources are truly harmful. GUEST: Frank Kelly Professor, Imperial College London | Director, Environmental Research Group https://www.imperial.ac.uk/people/frank.kelly The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Hidden Complexity of Particulate Matter 00:05:50 Understanding PM10, PM2.5, and Ultrafine Particles 00:08:01 The Lung as an Open Door: Why We're Vulnerable 00:09:52 The Meteor Effect: What Particles Are Really Made Of 00:20:41 The Seesaw Battle: Oxidative Potential and Free Radicals 00:25:46 The London Laboratory: Evidence That Drove the Ultra Low Emission Zone 00:59:13 The Indoor Air Quality Challenge: A New Frontier 01:11:43 The Kitchen Problem: Why Cooking Dominates Indoor Pollution 01:26:46 The Research Ecosystem: Eight Teams Tackling Air Quality 01:44:51 The Future: Real-Time Oxidative Potential Monitoring

This week, we dive into a question that challenges one of the most common assumptions in building energy efficiency: What if the chemical tests we use to validate air cleaning technology are completely missing the point—and what if the human nose is actually the most reliable instrument we have? The paper is titled A Method for Testing the Gas Phase Air Cleaners Using Sensory Assessment of Air Quality, published in the Journal of Building and Environment. It's authored by Cantor Amada, Lee Fang, Pavel Wargocki, and colleagues from Waseda University in Japan and the Technical University of Denmark. This research was conducted as part of the IEA Energy and Buildings and Communities Annex 78 project, and it proposes a radically practical testing protocol for gas phase air cleaners—one that puts human perception at the center, not just chemical spreadsheets. But here's the problem. Current standards typically test these air cleaners by challenging them with a few selected chemicals—measuring how well they remove formaldehyde, for example. But indoor air contains hundreds of different gaseous pollutants. If you only use chemical analysis on a handful of compounds, you might completely underestimate real-world performance. Worse, you might completely miss harmful byproducts the air cleaner is actually creating. Key Topics Discussed: Subtractive vs. Additive Air Cleaners: Subtractive cleaners remove chemicals using things like activated carbon. Additive cleaners decompose chemicals using active components like photocatalytic oxidation, ion generators, UV, or ozone. Some additive technologies can transform relatively harmless pollutants into dangerous unwanted species—or pump ozone into the space. If your chemical test isn't looking for those specific byproducts, the machine gets a pass grade while actively making the room worse. The Two-Phase Testing Protocol: Phase one is a screening phase—do no harm. The goal is simply to make sure the air cleaner doesn't have a negative effect on air quality. Phase two is the deep dive, testing the air cleaners at various ventilation rates from very low to standard levels, with panelists rating acceptability and odor intensity. The UVO Zone Device Failed Immediately: One additive air cleaner—a UVO zone device—actually increased the odor intensity in the room, particularly when humans were present. It was dropped from the study. An ion generator was allowed through to phase two just to see if poor results would be repeated. They were. It significantly decreased the acceptability of the air. Activated Carbon Worked—But Only for Building Materials: When the pollution source was purely building materials like old carpets and linoleum, the activated carbon air cleaners significantly improved air quality. But when the pollutant source was humans—people just sitting there breathing and existing—the air cleaners did not significantly improve perceived air quality. The Chemical Data Lied: Parallel chemical measurements showed that total VOCs dropped significantly when using the carbon air cleaners, regardless of whether the pollutant came from materials or humans. If you were only looking at the chemical spreadsheet, you would say the air cleaners worked perfectly in all scenarios. But the human panelists were telling a completely different story. The chemical measurements simply did not match the sensory evaluations. The ISO 16000-44 Standard: This research heavily supports the new ISO 16000-44 standard approved in 2023, which outlines the test method for measuring perceived indoor air quality to test the performance of gas phase cleaners. The sector is slowly recognizing that the human experience is a metric. A Method for Testing the Gas Phase Air Cleaners Using Sensory Assessment of Air Quality https://doi.org/10.1016/j.buildenv.2024.111630 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Challenge of Testing Gas Phase Air Cleaners 00:01:14 The Energy Dilemma: Why Air Cleaners Matter for Buildings 00:02:12 The Chemical Testing Problem: What Current Standards Miss 00:02:53 Additive vs Subtractive: Understanding Air Cleaner Technologies 00:03:43 The Human Nose Solution: Sensory Assessment as a Testing Method 00:04:04 The Experimental Setup: Real Materials and Real People 00:04:50 Phase One Results: The Do No Harm Screening 00:05:54 Phase Two Deep Dive: Testing at Various Ventilation Rates 00:06:31 The Big Reveal: When Chemical Data Doesn't Match Human Experience 00:07:28 The Massive Implication: Why Chemical Analysis Alone Fails 00:08:21 The Path Forward: ISO 16000-44 and Sensory Testing Standards 00:09:24 Closing Thoughts: The Human Nose Remains Essential

This week, we sit down with Mark Lynn, Managing Director of Eden Renewable Innovations and Chair of the Alliance for Sustainable Building Products, to explore a question that cuts to the heart of indoor air quality: What if the materials we bring into our buildings are the forgotten foundation of healthy indoor air—and what if natural materials offer solutions we've systematically overlooked for decades? Recorded live at the Alliance for Sustainable Building Products Annual Healthy Buildings Conference in London, this conversation takes us deep into the world of building materials, their chemistry, their moisture behavior, and their profound impact on the air we breathe indoors. Mark brings over two decades of experience in natural fiber insulation and nearly 30 years in natural building materials, with a particular focus on building physics and the chemistry of materials. Key Topics Discussed: The Forgotten Inflection Point: In the mid to late 1990s, society cared deeply about indoor air quality. MDF was scrutinized for formaldehyde emissions. Smoking bans were introduced. Ventilation moved up the agenda. But somewhere around the early 2000s, we shifted our focus entirely to ventilation as the sole solution—and stopped asking hard questions about the materials themselves. The Chemical Experiment: A single 1970s living room contained perhaps a dozen materials, most locally sourced. Today's living rooms contain thousands of materials, sourced globally, with complex chemistries we barely understand. We are living in a grand chemical experiment, and the results won't be clear for decades. Hurdle Technology and the Swiss Cheese Model: Ventilation alone is not enough. Good indoor air quality requires multiple layers of defense—elimination of harmful materials at source, moisture buffering through hygroscopic materials like wood and wool, and only then, ventilation as a final backstop. Relying on ventilation alone assumes it works perfectly. It rarely does. The Moisture Problem: Ventilation removes 95% of moisture from a building. But the remaining 5% can cause catastrophic problems—mold, structural decay, and poor air quality. Natural materials like sheep's wool and wood fiber can buffer moisture safely, acting as a critical redundancy when ventilation underperforms. Wool and Formaldehyde: Sheep's wool uniquely reacts with formaldehyde through a condensation reaction, permanently binding the carbon from formaldehyde into the keratin protein structure of the fiber. It's not just inert—it's actively neutralizing a harmful indoor pollutant. GUEST: Mark Lynn Managing Director, Eden Renewable Innovations | Chair, Alliance for Sustainable Building Products https://asbp.org.uk/ https://thermafleece.com/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Forgotten Fundamentals of Building Materials 00:02:19 The Inflection Points: When We Cared About Indoor Air Quality 00:05:16 The Chemical Soup: Living Rooms Then and Now 00:08:16 The Grand Chemical Experiment: Unknown Long-Term Impacts 00:10:58 Custodianship and Consumption: The Lost Art of Make Do and Mend 00:13:07 Particles as Trojan Horses: The Chemistry Happening in Your Home 00:15:22 Hurdle Technology: The Swiss Cheese Approach to Risk Management 00:17:34 Learning from Food: Why Digestive Biscuits Have Better Moisture Science 00:20:15 The Ventilation Fallacy: What Happens When Your Backup Plan Fails 00:25:00 Natural Technology: The Evolution Already Solved the Problem 00:32:59 The Standards Dilemma: Innovation Versus Established Frameworks 00:36:00 Post-Completion Reality: When Sensors Reveal the Truth 00:38:27 Transparency and AI: The Coming Revolution in Material Selection 00:57:59 Sheep's Wool and Formaldehyde: When Materials Fight Pollutants 01:01:20 The Trajectory Forward: Capacity, Policy, and Bottom-Up Change 01:04:39 From Belfast to Buildings: Optimism Through Experience

This week, we step outside the usual world of homes, schools, and offices to ask a question that might reshape how we think about the hospitality industry: What if the physical performance of a hotel room matters just as much as the quality of service—and what if guests are already telling us this in their online reviews? The paper is titled The Impact of Indoor Environmental Quality on Tourist Accommodation Ratings Using Guest Reviews, published in the Journal of Building and Environment. It's authored by Fan Zhang and colleagues from Griffith University, the University of New South Wales, and several other international institutions. Using web mining and artificial intelligence, they analyzed over half a million Booking.com reviews from Australian hotels and serviced apartments to understand how indoor environmental quality—air quality, acoustics, thermal comfort, lighting—actually drives guest satisfaction and ratings. Traditionally, measuring occupant satisfaction in hotels has been nearly impossible. Post-occupancy evaluations require structured surveys, but try getting a business traveler rushing to the airport at 6am to fill in a 20-page questionnaire about ventilation rates. It's just not going to happen. So instead, these researchers used natural language processing to extract the actual, unprompted words from guests who stayed in these places—to see exactly what they care about. Key Topics Discussed: Three Factor Theory: A framework that categorizes any product or service feature into three buckets: basic factors (dissatisfiers), performance factors (the better it is, the happier you are), and excitement factors (unexpected bonuses). Almost all indoor environmental quality factors function as basic factors—guests expect them to be good, and if they're not, ratings plummet. The Big Three Failures: Poor cleanliness, poor indoor air quality, and bad acoustics were the specific failures that dragged accommodation ratings down the most. Stuffy rooms, musty smells, and hearing the elevator rattling through the walls all night are directly torching hotel revenues by driving down public ratings. Indoor Environmental Quality Accounts for 33% of Guest Ratings: In budget hotels, nearly a third of a customer's overall rating is driven by indoor environmental quality. In luxury accommodation, it's still about 24%. You can have the best marketing team and the friendliest staff, but if your building is fundamentally underventilated, your business will suffer. The COVID Effect: The pandemic drastically amplified our sensitivity to poor indoor environments. During COVID, the negative impact of poor indoor air quality and cleanliness on guest ratings got significantly stronger. People suddenly equated visible cleanliness and fresh air with their own personal safety and survival. The View Exception: In budget accommodation, a nice view was an excitement factor—people didn't expect it, so when they got one, they were thrilled. But in luxury hotels, the view reverted to being a basic factor. If you're paying 5-star prices, you expect 5-star views. The Case for IEQ Benchmarking: The researchers suggest that policymakers and industry leaders should implement formal indoor environmental quality benchmarking for hotels—similar to Australia's NABERS rating for office buildings. Imagine being able to check a hotel's certified ventilation and air quality rating before you even book a room. The Impact of Indoor Environmental Quality on Tourist Accommodation Ratings Using Guest Reviews https://doi.org/10.1016/j.buildenv.2025.113135 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Overlooked Environment of Hotels 00:01:21 The Hospitality Blind Spot: Service vs Environment 00:01:52 The POE Problem: Why Traditional Surveys Fail in Hotels 00:02:24 The AI Solution: Mining Half a Million Guest Reviews 00:02:56 Three Factor Theory: The Framework for Understanding Buildings 00:04:06 The Eye-Opening Results: IEQ as a Basic Factor 00:05:03 The Triple Threat: Cleanliness, Air Quality, and Acoustics 00:05:44 The View Exception: Budget Thrills vs Luxury Expectations 00:06:30 The COVID Effect: When Air Quality Became Survival 00:07:53 The Bottom Line: IEQ Accounts for 33 Percent of Hotel Ratings 00:08:37 The Future: IEQ Benchmarking and Certification for Hotels 00:09:18 Study Limitations and the Reality of Guest Perception 00:09:55 The Main Takeaway: Engineering as Front-Line Business Survival

This week, we sit down with Adam Muggleton, Chief Technical Officer at AESG and host of the Edifice Complex Podcast. Adam's career spans project management, property development, and commissioning across 21 countries—from the UK to the Middle East and North America. He views buildings not as architectural statements, but as complex machines that are likely underperforming. With decades of experience and zero patience for performative sustainability, he has developed a reputation for dismantling corporate jargon and shining a light on poor engineering and mediocre outcomes in the construction industry. His relentless focus is on commissioning and building performance. He doesn't just want to know if a building looks good at sunset—he wants to know if the HVAC actually works, if the air is healthy, and why the industry persists in delivering glorified caves with modern price tags. Beneath his sceptical, no-nonsense exterior lies a deep advocacy for human-centric design, driven by the belief that the only way to fix the construction industrial complex is through radical transparency, rigorous testing, and a refusal to accept average as the industry standard. Key Topics Discussed: The Commissioning Accident: How Adam fell into commissioning engineering by accident—and why commissioning is always an accident. No one wakes up at 16 and says they want to be a commissioning engineer. Yet it's one of the most critical roles in delivering functional buildings. The Consequences Problem: Why the construction industry is the only industry in the world where you can send out a set of documents riddled with errors and omissions—and not pay for those mistakes. Why there are no real consequences for poor delivery, and how that shapes everything from design to handover. Humans at the Centre of Buildings—A Waste of Time? A brutally honest discussion about whether the rhetoric of "humans at the center" actually matters when residential developers are at the bottom of the care chain, and the only real feedback that matters is whether people stop buying. The Elon Musk Question: Who is the Elon Musk of the built environment? Who is innovating, crushing it, doing the impossible? And why Adam's daughter and her engineering friends would rather flip burgers than work in the built environment. The Platinum Building Paradox: Why even high-performance buildings with all the badges can fail spectacularly—like a healthy buildings conference held in a room where everyone is sitting in a fog of their own breath because the ventilation can't handle 80 people. GUEST: Adam Muggleton - Chief Technical Officer, AESG | Host, Edifice Complex Podcast https://www.linkedin.com/in/buildingwhisperer/ https://aesg.com/uk/ https://creators.spotify.com/pod/profile/edifice-complex-podcast2 The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Accidental Commissioning Engineer 00:03:18 The Property Development Perspective: When Commissioning Becomes an Afterthought 00:04:50 The Consequence Problem: Why Construction Keeps Making the Same Mistakes 00:06:27 The Complexity Trap: Why Buildings Are So Difficult to Get Right 00:09:47 The Defects Dilemma: Cars vs Buildings and the Zero Defects Dream 00:10:51 The R&D Desert: Why Construction Firms Don't Invest in Innovation 00:15:49 The Building Hierarchy: Who Gets Good Air and Who Doesn't 00:19:09 The Human-Centric Building Myth: Why Residential Is at the Bottom 00:32:24 Breaking the Cycle: Commissioning as a Compliance Tool 00:51:19 The Supply Chain Reality: Who Really Designs Your Building 01:05:05 The Elon Musk Question: Where's the Innovation in Construction? 01:13:44 The Platinum Plaque Problem: High-Performance Buildings That Don't Perform 01:17:34 The Visibility Solution: Open Source Performance Data and Property Tax Penalties 01:20:41 The Housing Crisis: Why Government Must Get Back in the Game 01:37:35 The Optimistic Conclusion: Why Construction Is Still a Great Career

This week, we tackle a question that goes to the heart of the performance gap in buildings: What if the problem isn't just poor construction or shoddy installation—but the data we're feeding into our models in the first place? There's an old saying in computer science: garbage in, garbage out. If you feed a perfect model with bad assumptions, you get a perfect calculation of a fantasy. And that's exactly what's been happening in indoor air quality modeling for decades. We've been relying on scattered, outdated, inconsistent emission rate data—pulled from 1990s conference papers, paywalled journals, and PDF reports buried in the internet—and wondering why our buildings don't perform as predicted. The paper is titled Pandora: An Open Access Database of Indoor Pollutant Emission Rates for Indoor Air Quality Modeling, published in the Journal of Building Engineering. It's the work of a huge international team, including Mark Adobati and colleagues from Annex 86, and it represents a massive effort to clean up the mess of data that indoor air quality modelers have been struggling with for years. Key Topics Discussed: The Data Problem: Why finding reliable emission rates for indoor pollutants has been a nightmare—scattered across thousands of sources, often in the wrong units, measured under weird conditions, and completely inconsistent. What Pandora Is: An open access, web-based database systematically compiling nearly 10,000 specific emission rates from the scientific literature, categorizing 740 different pollution sources—from paints and carpets to cleaning products, furniture, and even human beings. The Shocking Case Study: A simple child's bedroom modeled three different ways using data from Pandora. The total formaldehyde emission rate ranged from 342 micrograms per hour to over 6,000 micrograms per hour—a factor of 20 difference. If you designed ventilation based on the lower number, a trickle vent might be fine. Based on the higher number, you'd be installing industrial extraction. Why the Huge Discrepancy: The database contains data going back to the 1980s, when building materials were dirty—paints full of solvents, glues full of formaldehyde. Regulations like the French VOC label and German AGBB standard have forced manufacturers to clean up their act. If you use a statistical average of all data ever published, you're skewing your model with dirty data from 1995, predicting a problem that might not exist anymore. The Recommendation: Use the 25th percentile of the data for things like formaldehyde. This lower value is likely a much more accurate representation of modern, regulation-compliant materials. We might be systematically overestimating the chemical load from building materials if we rely on older datasets. Pandora: An Open Access Database of Indoor Pollutant Emission Rates for Indoor Air Quality Modeling https://doi.org/10.1016/j.jobe.2025.114216 Pandora Database: https://db-pandora.univ-lr.fr/ The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Data We Rely On 00:01:06 Garbage In, Garbage Out: The Input Data Problem 00:01:45 Introducing Pandora: A Massive Data Compilation Effort 00:02:27 The Scattered Data Nightmare: Why We Needed This 00:03:08 What's Inside: Construction Materials Dominate the Database 00:03:43 The Overlooked Sources: Cleaning Products and Human Pollution 00:04:34 The Case Study: A Child's Bedroom Reveals a Shocking Problem 00:05:41 The 20X Problem: Why Data Selection Method Matters Enormously 00:06:06 The Time Trap: Old Dirty Data Versus Modern Clean Materials 00:06:43 The Recommendation: Use the 25th Percentile for Modern Materials 00:07:03 The So What: We Might Be Solving Problems That Don't Exist Anymore 00:07:27 The New Risks: Recreational Chemicals and Activity-Based Pollution 00:08:17 The Living Project: Pandora Needs to Grow and Evolve 00:08:38 The Path Forward: From Guessing to Engineering Precision 00:08:59 Closing: Transparency and Understanding the Invisible Cloud

This week, we step into the world of moisture in buildings—one of the most overlooked yet critical aspects of indoor air quality and building performance. While we talk about humidity constantly, we rarely stop to break down what we actually mean. What is moisture? Is it a pollutant? And why does it matter so much? We sit down with David Schurk, owner of HVAC Insight Consultants and a dehumidification specialist with over 40 years of experience in the HVAC industry. David has led system design, application engineering, and field implementation efforts across healthcare, aerospace, industrial, and mission-critical environments. He's an ASHRAE life member and distinguished lecturer, and a course developer and instructor for multiple ASHRAE Learning Institute professional development programs. Key Topics Discussed: Is Moisture a Pollutant? How humidity impacts human comfort, building integrity, and health. Why 30% of the way we regulate our body temperature relies on evaporative cooling—and what happens when high humidity impedes that process. The Operating Room Problem: A vivid real-world example of how high humidity in hospital operating rooms causes surgeons to overheat, insist on colder temperatures, which paradoxically increases relative humidity further—creating condensation, discomfort, and potentially dangerous conditions. Breaking Down the Terminology: Dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, vapor pressure, dew point temperature—what do these terms actually mean? How do they interact? And why does relative humidity confuse everyone? The Psychrometric Chart: The beautiful, intimidating, and essential tool that maps the relationship between temperature and moisture. How to read it, why it matters, and why it's still relevant in the age of apps and AI. Surfaces, Condensation, and Mold: Why moisture risk is one of the few pollutants that can damage the building fabric itself. How dew point, surface temperatures, and adsorptive materials create the conditions for mold growth and structural decay. The Case for HVAC-D: Why dehumidification deserves its own prominent place in the HVAC world. How traditional air conditioning treats dehumidification as a byproduct of cooling—and why that doesn't always work. Desiccant Dehumidification: How solid and liquid desiccants can achieve moisture removal at levels traditional cold coil systems simply cannot reach—down to negative 100-degree Fahrenheit dew points. The applications in hospitals, pharmaceuticals, semiconductor manufacturing, lithium battery production, and ice rinks. GUEST: David Schurk - Owner, HVAC Insight Consultants https://www.linkedin.com/in/davidschurk/ The Air Quality Matters Podcast in Partnership with Particles Plus https://particlesplus.com/ Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Forgotten Child of Indoor Air Quality 00:02:27 Is Moisture a Pollutant? Defining the Problem 00:04:11 The Human Impact: Perspiration and Core Temperature 00:07:57 The Operating Room Problem: When Humidity Becomes Critical 00:14:30 Adding the D to HVAC: Why Dehumidification Deserves Recognition 00:28:59 Temperature Fundamentals: Dry Bulb, Sensible Heat, and Radiant Energy 00:36:05 Relative Humidity Explained: The Fish Tank Analogy 00:42:05 The Relative Humidity Trap: Why It Misleads Us 00:53:14 Absolute Humidity and Dew Point: The Real Measures That Matter 01:06:32 Wet Bulb Temperature: The Sling Psychrometer Explained 01:12:13 The Psychrometric Chart: Your Moisture Roadmap 01:18:21 Surfaces and Condensation: When Air Meets Materials 01:23:58 The Cold Spot Mold Spot Phenomenon 01:26:42 Controlling Moisture: The Thermostat Problem 01:30:59 The Efficiency Paradox: High SEER and High Humidity 01:32:55 Desiccant Dehumidification: Beyond the 32-Degree Limit 01:38:44 Real-World Applications: From Lithium Batteries to Pharmaceuticals 01:41:16 The Journey of a Dehumidification Jedi

This week, we dive into a question that goes beyond sensors and science: What actually motivates people to invest in clean air for their homes—and does culture change everything? The paper is titled Indoor Air Quality: Predicting and Comparing Protective Behaviours in Germany and Portugal, published in Indoor Air, and it's based on survey data from 800 participants split evenly between the two nations. This research uses Protection Motivation Theory to unpack the psychological and cultural drivers behind adopting indoor air quality technologies—things like sensors, air purifiers, and ventilation systems. Key Insights: Germany: Autonomy and Family Duty: For German participants, the biggest driver was self-efficacy—the feeling of "I can do this." They need to feel capable, empowered, and in control. There's also a strong link to benevolence caring—particularly protecting close family, especially children. In Germany, you're not buying an air purifier for yourself. You're buying it because you feel a personal responsibility to safeguard your immediate circle. Portugal: Prove It Works: For Portuguese participants, self-efficacy didn't move the needle. Instead, it was all about response efficacy—does this thing actually work? They're pragmatic consumers. If you tell them it works, you better be able to prove it. Also, people who already had respiratory conditions were much more likely to adopt the tech—health status mattered in Portugal, but not in Germany. Culture Eats Strategy for Breakfast: You can't use the same messaging in Berlin as you do in Lisbon. In Berlin, you say: "Take control of your home and protect your children." In Lisbon, you say: "This device is proven to reduce particulate matter by 99%." Fear Doesn't Work: Perceived vulnerability—the feeling that "I am personally at risk of getting sick"—had almost no impact on whether people adopted the technology. None. But perceived severity did. People are motivated when they acknowledge that poor air quality is a serious global or environmental problem—but they aren't motivated by feeling personally weak or susceptible. The COVID Hangover: The authors suggest this might be a legacy of the pandemic. We became accustomed to taking protective measures—masks, sanitisers, ventilation—not because we were terrified for our own safety every day, but because we recognised the severity of the threat in a broader, almost civic sense. This is Part Five of a five-part series exploring the psychology and perception of risk around air quality and ventilation. Indoor Air Quality: Predicting and Comparing Protective Behaviours in Germany and Portugal https://doi.org/10.1155/2024/3006342 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Psychology of Air Quality Behavior 00:00:55 The Missing Episode: Germany and Portugal Study Context 00:02:12 The Research Framework: Protection Motivation Theory 00:03:07 Threat and Coping: The Two Mental Processes 00:03:59 The German Mindset: Self-Efficacy and Family Protection 00:04:59 The Portuguese Perspective: Prove It Works 00:06:10 One Size Doesn't Fit All: Cultural Messaging Matters 00:06:31 The Vulnerability Paradox: Fear Doesn't Drive Action 00:07:29 The COVID Legacy: Civic Responsibility Over Personal Fear 00:08:15 The Performance Gap Problem: Why Efficacy Matters 00:08:53 Demographics and Early Adopters: The Youth Factor 00:09:26 Study Limitations and Economic Context 00:09:52 The Key Takeaway: From Education to Empowerment 00:10:46 The Path Forward: Respect, Severity, and Solutions 00:11:17 Closing Thoughts: Understanding the Human Element

This week, we step into one of the most overlooked yet critical areas of air quality and health: the construction site. While we spend so much time talking about indoor air quality during the operational phase of buildings, there's an entire workforce—construction and demolition workers—who spend their careers in environments that are anything but operational. And the risks they face are profound. We sit down with Angie Brooker, Occupational Health Manager at Multiplex, to explore the layered, dynamic, and often invisible hazards of dust exposure in construction—and what one of the UK's most forward-thinking organisations is doing about it. Key Topics Discussed: The Three Categories of Dust: Wood dust, general construction dust, and silica dust—each with different risks, different sources, and different control measures. Why silica, particularly from artificial stone, has become a focal point of concern. The Complexity of Construction Environments: Why construction sites are uniquely challenging—dynamic spaces, changing materials, multiple trades working on top of each other, high turnover, and the constant tension between program deadlines and health protection. The Artificial Stone Crisis: How engineered stone (containing up to 90% silica) has caused an epidemic of accelerated silicosis globally—and why Multiplex has banned it on all upcoming projects. The Australia case study, the thousand cases identified, and the proactive public health response. Hierarchy of Controls in Practice: From elimination and substitution (banning artificial stone) to engineering controls (on-tool extraction, ventilation) to administrative controls (training, awareness, health intervention tours) to PPE (the right mask, worn correctly, every time). The RPE Challenge: Why respiratory protective equipment is the frontline defence—but also why it's so hard to get right. Facial hair, improper fit, leaving masks hanging like "Christmas decorations," the heat and discomfort, and the cultural resistance to wearing them. Health Intervention Tours (HITs): How Multiplex walks sites monthly, focusing purely on health hazards, giving positive feedback and room-for-improvement interventions, and using personal dust monitors to make the invisible visible. The Silica 25 Programme: Three pillars—prevention (banning artificial stone), protection (appropriate RPE, education, awareness), and detection (health surveillance, lung function testing, baseline chest X-rays). This is a conversation about risk, responsibility, and the long game. It's about recognising that construction workers deserve to retire healthy—and that every day we delay action, we're storing up a public health crisis for the future. GUEST: Angie Brooker - Occupational Health Manager, Multiplex https://www.linkedin.com/in/angie-brooker-abba85123/ https://www.multiplex.global/ https://www.lungsatwork.org.uk/ The Air Quality Matters Podcast in Partnership with Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Construction Workers and Air Quality Risk 00:01:38 Meet Angela Brooker: Occupational Health in Construction 00:03:59 The Dust Challenge: Categories and Construction Hazards 00:05:44 The Dynamic Construction Environment: A Complex Risk Landscape 00:14:46 The Latent Disease Problem: Why Long-Term Risks Get Ignored 00:20:23 The Liability Gap: Accountability for Chronic Occupational Disease 00:24:50 The Cultural Challenge: From Bravado to Protection 00:36:06 Artificial Stone and Silicosis: The Accelerated Epidemic 00:34:42 The Silica 25 Program: Prevention, Protection, and Detection 00:09:08 Housekeeping and Hidden Exposures: The Resuspension Risk 01:07:57 Respiratory Protection: The Mask Problem 00:31:48 Health Intervention Tours: Making Health Visible on Site 01:19:47 Monitoring and Measurement: Dust Tracking Technology 01:35:14 Health Surveillance: Early Detection and the Medical System 01:31:58 The Smoking Factor: Compounding the Risk 01:27:12 From Nurse to Construction: Angela's Journey 01:39:19 The Path Forward: Getting the Basics Right 01:42:12 Closing: Resources and Support for Construction Workers

This week, we dive into a powerful piece of research that moves beyond surveys and snapshots to ask: What actually motivates people in deprived urban communities to change their indoor air quality behaviours—and how long does it take? The paper is titled Psychological and Contextual Drivers of Indoor Air Quality Behaviours in a Deprived Urban Community: Evidence from Participatory Research, published in Building and Environment, and it's based on the Well Home Project—an 18-month longitudinal study tracking 110 households in West London. The Central Question Unlike most studies that rely on a quick one-off survey, this was participatory research. They didn't just treat residents as test subjects—they worked with them, engaged them, installed sensors in their homes, and followed them over time across four waves of surveys. This is crucial because we know that air pollution disproportionately affects deprived communities—people living in substandard housing, closer to busy roads, with higher rates of pre-existing health conditions. So understanding what drives them to act is absolutely vital if we want to address health inequalities. But here's the fascinating part: self-efficacy grew over time. At the start of the project, confidence didn't make a huge difference. But as the months went on, people with high self-efficacy became increasingly likely to act. Building that muscle of confidence—that feeling of "I can handle this"—is a process, not a switch. Key Insights: The Mold Effect—Visibility is Key: The strongest predictor of behaviour change in the entire study was the presence of visible mold and damp. If people saw mold, they acted. But mold is a late-stage indicator—by the time you see black spots on your wall, you've probably been breathing in damp air for months. We need to make other pollutants visible before the damage is done. Engagement is a Marathon, Not a Sprint: The longer people were involved in the Well Home Project, the more likely they were to change their behaviour. Sustained engagement is essential—not just a one-off flyer. What Actually Changed: Residents were most likely to report changes in window opening, cooking, and cleaning. But the only behaviours that showed a statistically significant increase over time were cooking and heating. Why? These might require more knowledge or confidence to adopt—things people learned through participation in the project. What Didn't Change: Smoking behaviour showed the lowest likelihood of change. Smoking is an addiction—a deeply habitual chemical dependency. Simply telling someone it's bad for indoor air is unlikely to break a nicotine addiction. Some issues require much more specific, targeted health interventions. The Education Paradox: Individuals with higher levels of education were actually less likely to adopt behavioural changes. The authors speculate this might be a ceiling effect—people with higher education might already be doing some of the right things before the study even started, so they had less room to improve. Participatory Research Works: By working with communities, the researchers didn't just gather data—they helped catalyze change. The residents who stuck with the project became more and more empowered to control their own environment. This is Part Four of a five-part series exploring the psychology and perception of risk around air quality and ventilation. Psychological and Contextual Drivers of Indoor Air Quality Behaviours in a Deprived Urban Community: Evidence from Participatory Research https://doi.org/10.1016/j.buildenv.2025.114089 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Psychology of Indoor Air Quality in West London 00:01:16 The Well Home Project: Participatory Research in Action 00:02:14 The Health Belief Model: Understanding What Drives Action 00:03:36 The Key Findings: Severity and Self-Efficacy Win 00:04:41 The Mold Effect: When Visibility Drives Action 00:05:32 Time and Confidence: The Longitudinal Effect 00:06:23 What Changed and What Didn't: Behavior Breakdown 00:07:49 The Education Paradox: Challenging Our Assumptions 00:08:39 The So What: From Scare Tactics to Empowerment 00:10:07 Closing Thoughts: Residents as Active Agents

Welcome back to a solo episode—it's just me this week, fresh off a plane from Las Vegas and the AHR Expo, and honestly, in a bit of a reflective mood. When you spend a week inside the ultimate sealed box that is Vegas—losing track of time, weather, and what the air is actually doing—it puts things in perspective. It's comfort manufactured at massive scale, designed to keep you sedated, happy, and spending money. And stepping back into the real world, looking at the sheer volume of noise landing on my desk—commissions, pledges, papers, announcements—I had to pause. The Central Question On one hand, we've never had more attention. We have the Global Commission on Healthy Indoor Air launching at the UN. We have the Global Pledge. We have Ashrae's new Indoor Environmental Quality Centre of Excellence. It feels like the ground is moving. But on the other hand, I look at who's in the room. I look at the jostling for position. And I have to ask: Is this a genuine revolution, or is it a narrative grab? Are we drawing a line in the sand for public health—or building a new VIP section for the haves, while the have-nots are left outside in the smog? Key Topics Discussed: The Narrative Grab: What happens when a grassroots movement gains enough momentum to become valuable—and the big institutions, legacy corporations, and governing bodies realize they need to own a piece of that story. Is the commission a natural reaction of a sector trying to organize itself? Absolutely. But is it also a narrative grab? Potentially, yes. Who's in the Room—and Who Isn't: When I scroll through the lists of participants and commissioners, I see a lot of familiar names. Big HVAC. Controls. Sensors. Certification bodies. Real estate. Western academics. But where is the social science? Where are the voices from the Global South—not satellite offices, but grassroots? Where are the housing activists fighting damp and mold in public housing? It feels heavy on corporate real estate, heavy on Western technocracy. The Risk of Premium Air: When you turn health into a premium product, you create a two-tier system: platinum-class air for Google headquarters, and the rest of us—schools with windows painted shut, social housing with fans that haven't worked since 2015, industrial units thick with process dust. If the narrative becomes owned by commercial real estate, does clean air become a luxury good you buy, rather than a fundamental human right that is owed? The Mandate Debate: A fascinating clash playing out in the academic literature right now. On one side, a paper in Science led by Lidia Morawska and others: Mandating Indoor Air Quality for Public Buildings. Bold, noble, seductive—strict numerical legal mandates for IAQ in public spaces. On the other side, a response from the folks at ISO TC 146 SC 6 and ASTM D22, raising a critical point: is a global mandate actually workable, or even dangerous? What happens when you apply a Western technological fix to a context that simply cannot support it? Indoor Environmental Quality—The Big Brother of IAQ: Intellectually, it makes sense. We have eyes, ears, skin, as well as lungs. But I'm terrified that air quality is going to get lost in this mix. We've spent decades trying to get people to care about the invisible. Now compare that to thermal comfort—if the room is two degrees too cold, complaints light up instantly. If we bundle IAQ into IEQ, my fear is the budget goes to the things people complain about. The money goes to new LED lighting, sound dampening panels, heat pumps—and the ventilation? Well, as long as nobody's fainting, we'll value-engineer the filters. The Air Quality Matters Podcast in Partnership with Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast) If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Reflections from Vegas and the Sealed Box Experiment 00:03:24 The Global Commission on Healthy Indoor Air: Progress or Narrative Grab? 00:04:47 Who's Missing from the Table? The Representation Problem 00:06:02 The Narrative Grab: When Air Quality Goes Mainstream 00:08:13 The Premium Product Problem: Clean Air as a Luxury Good 00:13:04 The Mandate Debate: Science Paper vs. Practical Reality 00:15:51 The Parachute Solution: Why One-Size-Fits-All Standards May Fail 00:19:00 Indoor Environmental Quality: The Marvel Movie Problem 00:24:38 The Broken Delivery System: When Platinum Buildings Fail 00:28:12 The Path Forward: From Talking Shops to Ground Truth

This week, we tackle a question that goes beyond sensors, standards, and science: Do you trust the people telling you the air is bad? And more importantly—does that trust, or lack of it, actually change what you do about it? The paper is titled Communicating Particulate Matter Risk: The Effects of Empoweredness and Trust in Government Information and Protective Behaviour, published in the International Journal of Urban Sciences, and based on research conducted in Seoul, South Korea. The Central Question We know air pollution is a killer—7 million premature deaths a year globally. Governments know this too. They push out information: air quality indexes, apps, text alerts, and behaviour recommendations. Wear a mask. Don't exercise outdoors. But here's the problem: not everyone listens. Even when the information is right there in front of them, people don't always take protective action. Why is that? This paper argues that the traditional models of risk communication—focusing on threat perception and efficacy—are missing something crucial: trust in the messenger. The Big Takeaway The study found that trust in government information acts as a moderator—a boundary condition. For people with low trust in the government's information, it didn't matter how much hope they had or how much they believed their mask could work. If they didn't trust the source, those feelings didn't translate into action. Trust unlocks the potential of the other motivations. It allows an individual's sense of empowerment to actually extend into behavioural change. Key Insights: Empoweredness Goes Beyond Individual Efficacy: The paper introduces an expanded concept of empoweredness that includes hope (visualizing a future with clean air), values (believing it's meaningful to reduce pollution), and collective response efficacy (believing we can fix this together as a society). Values Matter: People were more likely to take action if they felt that reducing PM was a worthwhile or meaningful thing to do—not just about self-preservation, but about environmental stewardship and intrinsic value. Hope Only Works With Trust: For people with low trust, hope might just be wishful thinking or even a form of denial. But with trust, hope becomes a driver for action. Collective Efficacy Needs a Trusted Conductor: Believing society can handle the risk only led to personal action if the person trusted the government information. People need to feel that the conductor of the orchestra is competent and honest before they're willing to play their part. Citizen Science as a Trust-Building Tool: By involving the public in data collection—giving them sensors, letting them see the data for themselves—you increase transparency. When people participate in the science, they trust the data. And when they trust the data, they're more likely to listen when you tell them how to protect themselves. Communicating Particulate Matter Risk: The Effects of Empoweredness and Trust in Government Information and Protective Behaviour https://doi.org/10.1080/12265934.2024.2344456 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: The Psychology of Trust in Air Quality 00:01:10 The Seoul Laboratory: Why This Study Matters Globally 00:01:39 The Information Paradox: Why Data Doesn't Equal Action 00:02:18 Beyond Fear: The Extended Parallel Process Model 00:03:10 Empoweredness: The Missing Piece of the Puzzle 00:03:40 The Secret Sauce: Trust in Government Information 00:04:00 The Research Results: What 513 Citizens Revealed 00:04:50 Values and Meaning: The Power of Intrinsic Motivation 00:05:52 The Trust Boundary: When Hope and Efficacy Turn On or Off 00:06:46 The Implications: Why Technical Proof Isn't Enough 00:07:53 Collective Efficacy and the Orchestra Conductor 00:08:25 Building Trust: Citizen Science as a Solution 00:09:43 The Big Takeaway: Engineers Must Become Trust Builders

We sit down with Dr. José Luis Castro, Director General Special Envoy for Chronic Respiratory Diseases at the WHO, to confront one of the most overlooked yet devastating health crises of our time: chronic respiratory diseases—specifically asthma and COPD. With over three decades of experience in global health leadership, he has dedicated his career to advancing sustainable health initiatives across developing countries and urban centres worldwide. The Central Question When a child can't breathe, everything else stops. But when an adult has COPD, the world kind of crosses the street. Why? COPD is the hidden respiratory crisis—often met with a shrug, silent judgement, or post-pandemic fear. We assume it's a consequence of lifestyle choices. We tell ourselves they brought it on themselves somehow, and in doing so, we give ourselves permission to look away. This judgement is a failure of empathy and a failure of society. Key Topics Discussed: The Scale of the Crisis: Over half a billion people affected. 3.5 million deaths every year. Yet only one article in the New York Times in 2024—an obituary. Why chronic respiratory diseases are the Cinderella of public health. The Stigma Problem: How COPD has been framed as a "smoker's disease"—and why that narrative is both scientifically wrong and morally dangerous. The role of air pollution, occupational exposure, and early-life lung injury in creating this invisible epidemic. What COPD Actually Looks Like: A visceral, unflinching picture of life with COPD—from three oxygen cylinders (one by the bed, one in the toilet, one in the living room) to the slow suffocation of social isolation, breathlessness, and the erosion of dignity. Why breathlessness is invisible—and why that invisibility is deadly. The Indoor Air Connection: Why the majority of our exposure to outdoor air pollution occurs indoors. How the built environment—our homes, schools, and workplaces—is either protecting us or slowly poisoning us. The fundamental contract we have with buildings is broken. Environmental Justice: Why this is not just a problem for "the poor" or "smokers"—it's a problem for all of us. Anyone who breathes is at risk. And we are only one diagnosis away from being vulnerable ourselves. GUEST: Dr. José Luis Castro - Director General Special Envoy for Chronic Respiratory Diseases, WHO https://www.linkedin.com/in/jose-luis-castro/ https://www.emro.who.int/health-topics/chronic-obstructive-pulmonary-disease-copd/ https://www.who.int/ The Air Quality Matters Podcast in Partnership with Farmwood (\"https://farmwood.co.uk/\") - Eurovent (\"https://www.eurovent.eu/\") - Aico (\"https://www.aico.co.uk/\") The One Take Podcast in Partnership with SafeTraces (\"https://www.safetraces.com/\") and Inbiot (\"https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast\") Do check them out in the links and on the Air Quality Matters Website. (\"https://www.airqualitymatters.net/podcast\") If you haven't checked out the YouTube channel its here (\"https://www.youtube.com/@airqualitymatters-SimonJones\"). Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: The Silent Crisis of Chronic Respiratory Disease 00:02:31 Meet Jose Luis Castro: The WHO's Mission on Respiratory Health 00:04:44 The Staggering Numbers: Half a Billion People Affected 00:08:01 The Stigma Problem: Why COPD Gets Ignored 00:11:20 Clean Air as a Human Right: The UN General Assembly Pledge 00:13:46 From Numbers to Action: Making Air Quality Personal 00:17:30 The Inequality of Exposure: Environmental Justice and Air Quality 00:26:41 The Tobacco Parallel: Lessons from Successful Policy Change 00:29:28 Agency and Action: Why Individual Power Matters 00:36:43 The Invisible Organ: Why We Don't Talk About Lungs 00:39:17 Childhood Exposure: Creating Glass Ceilings for Young Lungs 00:43:38 What COPD Really Looks Like: A Paramedic's Perspective 00:47:33 Living with COPD: The Oxygen Tank Reality 00:52:58 The Coughing Boy: Social Isolation and Respiratory Disease 00:58:41 Beyond Smoking: The Real Causes of COPD 01:03:22 Early Detection and Spirometry: The Diagnostic Challenge 01:07:00 The Economic Case: Healthcare Costs and Productivity Loss 01:07:59 Occupational Health: Construction, Welding, and Workplace Exposure 01:14:25 The 2025 Breakthrough: Political Recognition at Last 01:17:01 Breaking Down Silos: Why Doctors Must Ask About Buildings 01:19:27 The Built Environment is in Us: Rethinking Our Relationship with Buildings 01:24:42 Jose's Journey: From TB to COPD 01:27:41 The Universal Threat: Why This Affects Everyone 01:33:15 Closing Thoughts: Breathing as the Starting Point

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. This week, we're diving into a paper that asks a deceptively simple question: If people could actually see the air they breathe, would they change their behavior? And perhaps more importantly for policymakers—is it worth the money to help them do it? The paper is titled Making the Invisible Visible: The Impact of Revealing Indoor Air Pollution on Behavior and Welfare, a working paper from the National Bureau of Economic Research by Robert Metcalf and Seffy Roth. And the results are, quite frankly, staggering. The Central Question We spend about 90% of our time indoors, and we know that indoor air can be significantly worse than outdoor air. But for most people, it's completely invisible—an unobserved good. You don't know if the air is toxic or pristine unless you have a monitor. And because you don't know, you can't manage it. So what happens when you make the invisible visible? The Big Takeaway This paper moves the conversation from health to economics—and it's sadly the language that often gets policy moving. It suggests that in this specific case, the deficit model—the idea that people just lack information—is actually true. When you give people the information, they do act. They do change their behavior. And that change is big. This paper tells us we need to stop treating indoor air quality as a private luxury and start treating it as a public health imperative with a massive economic upside. Whether it's monitors or air purifiers (which they also found had an infinite return on investment, by the way), the technology exists. We just need to make the invisible visible. This is Part Two of a five-part series exploring the psychology and perception of risk around air quality and ventilation. Making the Invisible Visible: The Impact of Revealing Indoor Air Pollution on Behavior and Welfare https://www.nber.org/papers/w33510 The One Take Podcast in Partnership with SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast) Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast) Chapters 00:00:00 Introduction: Making the Invisible Visible 00:01:14 The Invisible Problem: Why Indoor Air Quality Matters 00:01:44 The Study Design: A Clever Field Experiment in Camden 00:02:47 The Baseline Reality: What the Data Revealed Before Intervention 00:04:15 The Dramatic Results: 34% Reduction in Pollution Exposure 00:05:09 How They Did It: Ventilation Without Lifestyle Sacrifice 00:06:15 The Economic Case: Infinite Return on Investment 00:08:31 The Energy Efficiency Tension: A Critical Warning 00:09:28 Study Limitations: What to Keep in Mind 00:10:32 The Big Takeaway: Information Drives Action and Economic Value

In this essential episode, we sit down with Parag Cameron Rastogi, Director of Real Asset Analytics at GRESB, to explore one of the most powerful yet often misunderstood forces shaping the future of indoor air quality: how we measure, benchmark, and value the performance of buildings at scale. GRESB—the Global Real Estate Sustainability Benchmark—has trillions of dollars of assets in its system. It is the machinery behind how pension funds, investors, and asset managers assess risk, performance, and long-term value across portfolios spanning every continent, building type, and climate zone. And it is evolving—fast—from a disclosure-based model to a performance-based one. The Central Question We already have the tools and knowledge to deliver clean, healthy indoor air. So why is there still such a persistent gap between what we know works in theory and what actually happens in buildings? And how can we operationalize air quality data in a way that makes it financially material, benchmarkable, and valuable—not just for compliance, but for real-world decision-making? Key Topics Discussed: What GRESB Is and Why It Matters: How a standardized survey sent to building owners and managers became the global standard for assessing sustainability risk in real estate—and why pension funds with 50-year time horizons care deeply about the long-term performance of the assets they invest in. From Disclosure to Performance: The seismic shift happening in 2028, when GRESB moves from rewarding having data to rewarding what that data shows. Why this is a big deal for the industry—and what it means for air quality. The Binary Nature of Data: Why building portfolios either have full data coverage or almost none—and nothing in between. The fascinating bimodal distribution of data availability, and what it tells us about control, building type, and lease structures. Relative Benchmarking vs. Absolute Thresholds: Why finance speaks the language of risk, not absolutes. How GRESB uses relative benchmarking to compare buildings in context—and why this approach might be the missing piece in how we communicate air quality risk. This is a conversation about risk, value, and the machinery of change. It's about recognizing that if we want air quality to matter in the real world, we need to speak the language of the people who control the capital. We need to make it benchmarkable, measurable, and material. And we need to move from fluffy aspirations to hard performance. https://www.linkedin.com/in/rastogiparag/ https://www.gresb.com/ HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST: Parag Cameron Rastogi - Director of Real Asset Analytics, GRESB The Air Quality Matters Podcast in Partnership with Farmwood - Eurovent - Aico The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: GRESB and the Global Real Estate Sustainability Benchmark 00:02:00 What is GRESB? Origins and the Investor's Need for Risk Transparency 00:05:30 From Portfolio to Asset Level: The Evolution of GRESB Assessment 00:10:50 The Foundation and the Industry: How GRESB Standards are Governed 00:15:45 Data Coverage: The Binary Reality of Building Performance Data 00:24:00 The Disclosure to Performance Paradigm Shift 00:34:00 Control Structures and the Triple Net Problem 00:44:00 Relative Benchmarking: Why Context Matters in Risk Assessment 00:54:00 The Long Tail of Real Estate: Addressing the Forgotten Buildings 01:03:45 Operationalizing Data: From Collection to Business Value 01:12:00 The Automotive Analogy: Building Feedback Loops for Improvement 01:22:00 Stars, Quintiles, and Narrative-Based Rankings 01:32:00 Sustainability-Linked Loans and the Financial Incentive 01:42:00 Indoor Air Quality's Journey: From Disclosure to Performance Pillar 01:52:00 Beyond Productivity: Health, Harm, and the DALY Framework 01:58:00 The Predictive Future: From Rearview Mirror to Digital Twin 02:03:00 Parag's Journey: From Building Physics to Real Estate Finance 02:07:00 Closing Thoughts: The Power of Scale and Systemic Change

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. This week, we step away from the physics and chemistry of air quality and dive firmly into the psychology of how we perceive—and crucially, misperceive—the air around us. The paper is titled Why Do We Misperceive Air Pollution? A Scoping Review of Key Judgmental Biases, published in Air Quality, Atmosphere & Health, and it systematically dismantles a dangerous assumption many of us hold: that if we just give people the data—the graph, the PM2.5 reading, the red light on a sensor—they'll change their behaviour. The Central Question Why do we struggle so much to communicate the risk of poor air quality, particularly in our homes? And why do technical solutions—ventilation systems, sensors, standards—so often fail to deliver the health outcomes we expect? The answer, this paper argues, is that our brains are essentially wired to misinterpret or even ignore the quality of the air we breathe, regardless of the facts. Information does not equal action. Perception is not reality—but for the person living in that home, perception is their reality. The Six Psychological Biases That Blind Us to Air Pollution The Big Takeaway: Our current approach to communication—largely based on "deficit models" (the idea that people just lack information)—is fundamentally flawed. We can't just put a sensor in a room, point to the red light, and expect people to behave differently. These biases are working in the background to minimize that signal. If someone has a home halo effect, they'll look at the red light and think the sensor is broken, rather than their air is toxic. To be effective—whether as engineers, consultants, housing officers, or policymakers—we need to stop treating occupants like passive recipients of data. We need to understand the social and psychological context they live in. We need to acknowledge emotional connections, offer alternatives that provide the same sense of comfort without the emissions, and recognize that unless we bridge the gap between technical reality and lived perception, all the ventilation systems in the world won't deliver the health outcomes we want. The technical solution is only half the battle. The messy, biased, emotional human element is where the real challenge lies. This is Part One of a five-part series exploring the psychology and perception of risk around air quality and ventilation. Why do we misperceive air pollution? A scoping review of key judgmental biases https://doi.org/10.1007/s11869-024-01650-y The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: The Psychology of Air Perception 00:01:19 The Assumption We All Make: Data Equals Action 00:02:33 Sensory Capacity: When Our Senses Fail Us 00:03:10 Habituation: The Nose Blindness Phenomenon 00:03:54 The Home Halo Effect: My Sanctuary Can't Be Toxic 00:05:07 Confirmation Bias: Pollution Happens to Someone Else 00:05:44 The Exclusion Effect: Bigger Problems Crowd Out Air Quality 00:06:29 The Affect Heuristic: Emotion Over Evidence 00:07:33 The So What: Rethinking Communication and Engagement 00:09:29 The Big Takeaway: Perception is Their Reality 00:10:15 Closing: Part One of Five on Psychology and Risk Perception

We sit down with John O'Connor, former chair of Ireland's Housing Commission, and Neil Freshwater, Public Affairs Manager for GB and Ireland at Velux, to explore one of the most complex challenges facing Ireland and Europe today: how do we deliver affordable housing at pace while ensuring homes are healthy, sustainable, and fit for purpose? Recorded at a Healthy Homes Ireland event in Dublin just before Christmas, this conversation tackles the fundamental tensions in housing policy—between volume and quality, affordability and performance, political cycles and long-term planning. With Ireland's new housing plan published, the European Commission preparing its first-ever affordable housing plan, and the revised Energy Performance of Buildings Directive due to be transposed into Irish law by May 2026, the stakes have never been higher. The Central Question We've understood for over a century that housing and health are inseparable. Yet somehow, in our rush to solve the housing crisis, we've fragmented that relationship. How do we get back to first principles? How do we ensure that every home—not just the expensive ones—delivers good air quality, daylight, thermal comfort, and the conditions for families to thrive? Key Topics Discussed: The Housing Commission's Vision: Why Ireland's housing crisis isn't just about numbers—it's about creating a cohesive society where having a home is a fundamental right, not a luxury. The Commission's recommendations as a long-term, interconnected menu—not a pick-and-mix. The Forgotten Link Between Health and Housing: How ventilation and daylighting were central to 19th and early 20th-century housing standards—and why we've lost that focus in modern construction. The sobering reality that people John knows are now suffering terminal illnesses due to poor indoor air quality. Fast, Cheap, and Good—Pick Any Two: The political and economic pressures driving volume over quality. Why "any shelter is better than no shelter" is a dangerous narrative—and how 5,000 children experiencing homelessness in Ireland today (compared to fewer than 100 a decade ago) lays bare the human cost of failure. The One-Dimensional Trap: How the Energy Performance of Buildings Directive initially focused only on energy efficiency—and why the inclusion of Indoor Environmental Quality (IEQ) in the revised directive is a game-changer, if we can translate it into policy and practice. Because at the end of the day, it's not about units. It's about homes. And homes are for people. HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUESTS: John O'Connor - Former Chair, Housing Commission, Ireland Neil Freshwater - Public Affairs Manager, Velux GB & Ireland The Air Quality Matters Podcast in Partnership with Farmwood - Eurovent - Aico The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Housing, Health, and the Irish Context 00:02:56 Meet the Guests: John O'Connor and the Housing Commission 00:04:39 The Housing Crisis: Numbers, Demographics, and the Meaning of Home 00:09:25 Neil Freshwater: Velux's Origins in Healthy Buildings 00:16:25 The Trifecta Challenge: Fast, Cheap, and Good 00:17:52 The Forgotten Science: Air Quality and Ventilation in Housing 00:21:04 Daylight Inequality and the Quality Divide 00:45:56 The Monitoring Revolution: From Code Compliance to Performance 00:53:03 The Skills and Labour Crisis: Building at Lightning Pace 01:02:41 Modern Methods of Construction: Promise and Reality 01:05:01 Looking Forward: Ireland's EU Presidency and the Path Ahead 01:11:14 Closing: The Charter for Healthy Homes

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. This week, we're diving into one of the most complex and urgent environmental dilemmas of our time: the smoke from fires we set on purpose. The paper, Associations between PM2.5 from Prescribed Burning and Emergency Department Visits in 11 Southeastern US States by a team of researchers from Boston University, Georgia Tech, and other institutions, tackles a critical question: In our effort to prevent catastrophic wildfires through prescribed burning, are we creating a different, more chronic health problem from the smoke of these "good fires"? The Environmental Dilemma: Prescribed burning—intentionally setting smaller, controlled fires to clear underbrush—is one of our primary tools to fight the catastrophic wildfires made worse by climate change. But this tool has side effects: smoke containing fine particulate matter (PM2.5). The question is whether we're trading one health disaster for another. The Study: Researchers analyzed over 30 million emergency department visits from 11 southeastern US states over nearly a decade—a region where prescribed burning is common practice. Using sophisticated chemical transport models, they "tagged" PM2.5 in the air to identify which portions came specifically from prescribed fires, allowing them to isolate the health signal of just these controlled burns. The Surprising Findings: Yes, there is a link. On days with high levels of PM2.5 from prescribed fires, there was a statistically significant increase in emergency department visits for upper respiratory infections and, most notably, ischemic heart disease, which went up by about 6%. But here's the counter-intuitive part: For the classic signatures of smoke exposure—overall respiratory admissions, asthma, and COPD—they didn't find a statistically significant increase. This is what makes smoke from prescribed fires different from wildfire smoke. Why the Difference? The nature of the fires themselves. Wildfires are hot, intense, and chaotic, burning everything from the forest floor to the canopy. Prescribed burns are cooler and slower, designed to smolder through underbrush, grass, and leaf litter. This difference in what's burning and how it's burning creates a different chemical cocktail of smoke. Prescribed fire smoke tends to have lower concentrations of pollutants like carbon monoxide and polycyclic aromatic hydrocarbons (PAHs) compared to wildfire smoke. The Big Takeaway: Not all smoke is created equal. The health impact of PM2.5 is not just about the mass of particles in the air—it's about what those particles are made of, and it depends profoundly on the source. This research doesn't give us an easy answer. It doesn't say prescribed burning is safe or unsafe. Instead, it gives us a much more nuanced picture. It's a powerful reminder that there are no easy wins in environmental management—it's all a game of trade-offs. We're using a tool to reduce the risk of catastrophic wildfires, but that tool has its own health risks, and those risks are different. This kind of research is absolutely vital for land managers and public health officials because it helps them understand the specific health impacts of their decisions, allowing for more targeted warnings and a better, more honest conversation about the risks we're actually choosing to manage. Associations between PM2.5 from prescribed burning and emergency department visits in 11 Southeastern US states https://doi.org/10.1016/j.envint.2025.109770 The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: The Prescribed Burning Paradox 00:01:48 The Study Design: Tagging Smoke from Good Fires 00:02:54 The Findings: A Surprising Health Signal 00:04:02 Not All Smoke is Equal: The Chemistry Matters 00:05:32 The Big Takeaway: Environmental Trade-Offs and Honest Conversations 00:06:40 Closing: Thanks and Next Week

In this essential episode, we sit down with Paul O'Sullivan, lecturer in Sustainable Energy Engineering at MTU and co-lead of the MESO Research Group, to explore one of the most pressing—yet often overlooked—challenges in our built environment: how do we design buildings that don't overheat? Paul brings deep expertise in low-energy demand-side technologies, building retrofit strategies, indoor thermal environments, and ventilative cooling. His work sits at the fascinating intersection of thermal comfort, air quality, decarbonization, and the future resilience of our homes, schools, and workplaces. The Central Question We've spent decades designing buildings to be thermally comfortable in winter—airtight, well-insulated, energy-efficient. But in doing so, have we created a new problem? As our climate warms and our buildings become better at keeping heat in, how do we ensure they can also let heat out when they need to—without resorting to energy-intensive air conditioning? Key Topics Discussed: Thermal Comfort vs. Overheating: What's the difference between discomfort and a genuine health risk? Why overheating is not just about temperature, but about duration, vulnerability, and the capacity of a building to respond. The Unintended Consequences of Energy Efficiency: How our drive to decarbonize heating has created buildings that struggle to cool—and why Ireland's cooling season now starts in March. The Cooling Ladder: A design philosophy for tackling overheating—starting with prevention (solar shading, orientation), then modulation (thermal mass, phase-change materials), then dissipation (ventilative cooling), and only finally, supplementary mechanical cooling. Ventilative Cooling and the New CEN Technical Specification: How natural and mechanical ventilation can provide free, sustainable cooling—and why the European standard Paul helped develop is a game-changer for designers. The Performance Gap: Why buildings that look great on paper often overheat in reality—and why simulation tools are struggling to keep pace with the rate of climate change and building innovation. Agency and Adaptation: The power of openable windows, external shutters, and giving occupants control. Why buildings that allow people to adapt perform better—and why we've lost some of that agency in modern construction. This is a conversation about trade-offs, resilience, and the path forward. It's about recognizing that comfort isn't a luxury—it's a fundamental aspect of health, well-being, and productivity. And it's about designing buildings that work with their climate, not against it. DESCRIPTION: HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST:  Paul O’Sullivan - https://www.linkedin.com/in/paul-d-o-sullivan-441b9023/ The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Paul O'Sullivan and the Science of Thermal Comfort 00:02:18 Thermal Comfort vs Air Quality: Different Lenses on Indoor Environment 00:04:07 Maslow's Hierarchy: Is Comfort a Luxury or a Necessity? 00:05:34 The Decarbonization Dilemma: Energy Efficiency vs Thermal Comfort 00:09:31 Expectation and Adaptation: The Psychology of Thermal Experience 00:14:29 The Cooling Ladder: A Design Philosophy for Passive Solutions 00:15:44 Where Are We With the Science? Progress and Gaps in Thermal Comfort 00:24:07 Defining Overheating: From Discomfort to Health Risk 00:24:15 The Measurement Challenge: 20 Different Ways to Assess Overheating 00:27:52 Conditioned vs Free-Floating: Two Different Overheating Problems 00:37:09 Ireland's Paradox: Overheating in a Cool Climate 00:37:16 The Building as Battery: Thermal Mass and Night Cooling Strategies 00:52:55 The Performance Gap: Why Simulations Don't Match Reality 01:00:40 The Data Desert: Why We Don't Know How Our Buildings Perform 01:20:50 Behavior and Technology: The Human Element in Building Performance 00:49:07 Ventilation's Role: Free Cooling Potential and Air Quality Trade-offs 00:56:08 Heat Recovery Dilemma: Winter Efficiency vs Summer Cooling Needs 01:10:20 Hybrid Solutions: The Future of Resilient Cooling 01:40:55 Climate Shelters: Schools as Community Heat Wave Refuges 01:43:36 Double Jeopardy: When Heat Waves Meet Power Outages and Poor Air Quality 01:26:51 The MESO Research Group: From Ventilative Cooling to Citizen Science 01:29:44 Window Aerodynamics: The Forgotten Performance Metric 01:34:55 European Standards: Translating Research into Design Tools 01:48:26 Citizen Science: Engaging Occupants in Building Performance Research 01:51:30 The Path Forward: Data, Standards, and Human-Centered Design

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. This week, we're diving into a paper that tackles a question millions of us have been living with since the pandemic: What actually makes a good home office? The study is titled Home as an Office: Investigating the Associations Between Indoor Environmental Quality, Wellbeing and Performance in Work From Home Settings, and it explores a fascinating tension—between what sensors objectively measure and what people subjectively experience. The Setup: Researchers recruited 95 people working from home in Vancouver and Seattle and used a clever two-pronged approach. On one hand, participants were given desktop monitors that objectively measured PM2.5, total VOCs, CO₂, temperature, humidity, and sound levels—the hard numbers on the physical environment. On the other hand, they conducted detailed questionnaires asking people about their perceptions: Are you satisfied with the lighting? Do you have an ergonomic chair? Does noise from family interrupt you? They also measured outcomes using standardized surveys for psychological wellbeing, physical symptoms, and work performance. The Core Question: Which is the better predictor of wellbeing and productivity—the objective data from the sensors, or the subjective feelings of the occupants? The Surprising Finding: The data from the objective sensors—the actual measured levels of PM2.5, CO₂, and so on—showed predominantly weaker associations with how people felt or how productive they were. Even if CO₂ levels were a bit high or PM2.5 was slightly elevated, in this study it didn't have a strong direct link to reported wellbeing or performance. Why? The authors suggest that indoor environmental quality in most homes was generally moderate, but more importantly, people have agency at home. If you're cold, you can change the thermostat. If the air feels stuffy, you can open a window. This ability to control and adapt seems to weaken the direct link between what a sensor measures and how people actually feel. The Perception-Based Data Tells a Different Story: When researchers looked at subjective perception, they found much stronger connections. Satisfaction with ergonomic furniture, good daylight, and a pleasant workspace aesthetic were all strongly linked to positive wellbeing and performance outcomes. People who felt good about their physical setup felt better and worked better. The reverse was also true. Problems like unwanted interruptions from family, noise from the street, or even persistent kitchen odors were strongly associated with lower psychological wellbeing, reduced vitality, and depressed mood. The Big Takeaway: The paper's core message is not that objective indoor air quality doesn't matter—of course it does, especially at extreme levels. But in the context of working from home, our subjective experience of the space is a much better predictor of our wellbeing and performance than what a sensor might tell us. Perception really is reality here. The feeling of being in control, having a comfortable and aesthetically pleasing space, and not being constantly interrupted—these are not just fluffy nice-to-haves. The study shows they have measurable, statistically significant associations with our mental health and productivity. The Implications: This challenges a purely engineering-led, sensor-driven approach to creating healthy buildings. It tells us we can't just focus on hitting certain parts per million. We need a more holistic, human-centered approach. When we design spaces for home working—or frankly, any space—we need to think just as much about ergonomics, acoustics, privacy, and personal control as we do about ventilation rates. Home as an office: Investigating the associations between indoor environmental quality, well-being, and performance in work-from-home settings https://doi.org/10.1016/j.buildenv.2025.113310 The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: The Home Office Question We've All Been Asking 00:01:35 The Study Design: Measuring Both Objective and Subjective Reality 00:02:55 The Surprising Finding: Sensors Don't Tell the Whole Story 00:03:32 The Agency Factor: Why Home is Different from the Office 00:04:05 Perception is Reality: The Power of Subjective Experience 00:04:41 The Problems That Matter: Interruptions, Noise, and Kitchen Odors 00:05:07 The Big Takeaway: Beyond Parts Per Million 00:05:53 Implications: A Human-Centered Approach to Indoor Spaces 00:06:40 The Validation: Your Uncomfortable Chair Really Does Matter 00:07:07 Closing: Thanks and Next Week

In this episode, we sit down with Bart Cremers, Group Knowledge Consultant at Zehnder Group International, to explore one of the most critical—yet often overlooked—challenges in advancing indoor air quality: how industry and academia can collaborate more effectively. Bart occupies a fascinating position, straddling the worlds of industry and research, product innovation and scientific rigour. With deep expertise in physics, renewable energy, data analysis, and business development, he has spent years translating fundamental science into real-world ventilation solutions—and feeding real-world performance data back into the research community. The Central Question: We already have the tools and knowledge to deliver clean, healthy indoor air. So why is there still such a persistent gap between what we know works in the lab and what actually happens in people's homes? And how can we unlock the enormous potential that exists when industry and academia work together properly? Key Topics Discussed: The Two Silos: Why industry and academia often work on the same problems but from fundamentally different perspectives—and why bridging that gap is essential for progress. What Industry Brings to Research: Real-world performance data, field monitoring at scale, the ability to tell stories rather than just specs, and the crucial feedback loop between lab performance and lived experience. What Academia Brings to Industry: Scientific rigour, peer review, freedom to explore problems without immediate commercial pressure, and the discipline to ask—and answer—the right questions. The Speed Problem: Why academic research can take five or six years from conception to publication—and by that time, the technology being studied is often two generations out of date. The Performance Gap: Why so much academic research ends up measuring poorly installed or maintained ventilation systems—and what that means for our understanding of what good ventilation can actually achieve. Models vs. Reality: The critical importance of validating simulations and models with real-world data—and how industry can provide the field measurements academia desperately needs. The Minimum Becomes the Maximum: How regulations and standards, by nature, lag behind innovation—and why designing to minimum compliance is a race to the bottom that leaves everyone worse off. The Future: Ventilation as a Service: Why the shift from selling products to selling clean air and healthy outcomes could fundamentally transform the industry—and close the performance gap for good. Multifunctional Systems: The promise and peril of integrating ventilation with heating, cooling, and other building systems—and why we need to get the basics right first. Retrofit and Renovation: Why the next frontier isn't just new build, but bringing healthy indoor air to the billions of existing buildings—and why that requires a completely different approach. Citizen Science: The untapped potential of involving real people in real homes in the research process—not just as data sources, but as co-creators of the questions we need to answer. This is a conversation about friction, opportunity, and the path forward. It's about recognizing that both industry and academia have blind spots—and that the only way to truly advance indoor air quality is to work together, with mutual respect, shared goals, and a willingness to learn from each other's strengths. HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST: Bart Cremers: https://www.linkedin.com/in/bart-kremers/ The Air Quality Matters Podcast in Partnership with Zehnder Group - Farmwood - Eurovent - Aico - Aereco - Ultra Protect The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Bridging Industry and Academia in Air Quality 00:03:17 The Two Worlds: Understanding Industry and Academic Perspectives 00:07:05 The Friction and Opportunity: Why Collaboration is Challenging 00:13:48 Real World vs Lab: The Performance Gap Problem 00:16:00 Communication Challenges: Telling Stories vs Presenting Specs 00:25:14 The Speed Problem: When Research Can't Keep Up with Innovation 00:33:26 The Value Exchange: What Industry Brings to Research 01:00:01 The Installation Crisis: Measuring Poorly Installed Systems 01:04:35 The Minimum Becomes the Maximum: Engineering for Redundancy 01:09:08 Closing the Gap: Training, Education, and Consumer Protection 01:15:31 The Future: Renovation, Smart Controls, and Ventilation as a Service 01:31:40 Multifunctional Systems: The Promise and Complexity of Integration 01:42:52 Closing Thoughts: Building for People in a Complex Future

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. This week, we're at a paper that tackles a fundamental question: Where exactly should we put indoor air quality sensors? How many do we actually need? And how often should they take readings? The paper is titled Long-term Indoor Air Quality Monitoring in Office Buildings: Data-Driven and Goal-Oriented Recommendations for Sensor Replacement and Sampling Frequency, and it's all about moving from guesswork to evidence-based monitoring strategies. The Problem: Existing standards are all over the place. One might say you need a sensor every 50 square meters, another says 325 is fine. One says sample every 15 minutes, another says 30 is okay. There's a real lack of clear, evidence-based guidance—and if you get it wrong, you're either spending a fortune on equipment you don't need, or you're collecting data that's useless or actively misleading. The Study: Researchers installed 16 sensors across three office sites in Shanghai and collected four years of data on PM2.5, PM10, and CO₂—taking readings every single minute. They then analyzed the spatial and temporal patterns to answer the critical questions: Does a sensor over here tell the same story as one over there? And what information do you lose if you sample every hour instead of every minute? Key Findings: Particulate Matter (PM2.5 & PM10): The dominant driver is outdoor air. Indoor PM levels tracked outdoor levels very closely, meaning infiltration is the key factor. For tracking general trends, you don't need a massive density of sensors—readings from different locations were highly correlated. CO₂: A Completely Different Story: CO₂ is generated indoors by occupants, and the study found huge differences depending on sensor location. Key factors included the type of HVAC system, room size, distance from windows, and proximity to air outlets. A single sensor in a large, complex office space just won't cut it. The Goal-Oriented Approach: Here's where the paper gets clever. The authors argue that we're often trying to do two different jobs with monitoring, and we need to separate them: Job #1 - Temporal Trend Monitoring: Understanding the big picture—daily cycles, seasonal changes, overall average conditions. For this, you can use about one sensor every 150 square meters, and sampling intervals of 90 minutes for PM and 130 minutes for CO₂ are sufficient without losing accuracy. This means less data to store, less energy use, and less maintenance. Job #2 - High Concentration Event Monitoring: Catching the bad stuff—short, sharp spikes in pollution when a meeting room fills up or outdoor smoke floods in. For this, you need much more frequent sampling: every 4 minutes for PM2.5 and CO₂, and every 15 minutes for PM10. You also need more sensors placed strategically in high-risk zones—large rooms, spaces with standalone AC units, and areas far from ventilation sources. The Big Takeaway: There's no single "right" way to monitor indoor air quality—it all depends on your goal. This paper gives us a data-driven framework for making that choice. If you want to understand long-term building performance, you can use a sparse network sampling infrequently. But if your primary goal is health and safety—protecting occupants from pollution peaks—you need a denser, targeted network sampling much more often. This is about being deliberate. It's about monitoring with purpose. Long-term indoor air quality monitoring in office buildings: Data-driven and goal-oriented recommendations for sensor placement and sampling frequency https://doi.org/10.1016/j.buildenv.2025.113392 The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: The Fundamental Questions of Air Quality Monitoring 00:01:35 The Problem: Inconsistent Standards and Guidance Gaps 00:02:02 The Study Design: Four Years of Data from Shanghai Offices 00:02:38 Particulate Matter Findings: Outdoor Air Drives Indoor Trends 00:03:14 CO2 Findings: The Complexity of Indoor-Generated Pollutants 00:03:47 The Goal-Oriented Approach: Two Different Monitoring Jobs 00:04:37 Trend Monitoring: Less is More for General Performance 00:05:19 Event Monitoring: Frequent Sampling for Health and Safety 00:06:15 The Big Takeaway: No Single Right Way to Monitor 00:06:59 Closing: From Good Ideas to Smart Strategies

To celebrate 100 episodes of the Air Quality Matters podcast, we welcome back our very first guest, the renowned Max, for a wide-ranging discussion on the past two years and the revolutionary future of Indoor Air Quality (IAQ). Max, one of the leading voices in air quality standards, dives into the major themes that have dominated the conversation, including the post-pandemic landscape, the rise of health-focused standards, and the critical importance of Particulate Matter (PM) control. In this episode, you will learn: The Health Convergence: How the medical community and engineering discipline are finally converging to tackle IAQ, driven by the ability to measure environments more accurately. The Post-Pandemic Bubble: Why the huge spike in interest around airborne disease has led to a feeling of "general disappointment" in the industry, and where the real progress is being made. Particulate Matter (PM): The Big Problem, Simple Fix: Why PM is the major component of indoor air harm and how simple engineering controls like filtration are the cost-effective solution. The DALY Revolution: A deep dive into Disability Adjusted Life Years (DALYs) and how Max’s work uses this public health metric to move away from arbitrary ventilation flow rates and quantify the actual harm of indoor contaminants in ASHRAE 62.2. The CO2 Myth: Max’s famously animated argument on why CO2 is not a good indicator of indoor air quality and is, in fact, an international engineering problem. A 9-Year Deadline: Max's personal mission to completely phase out ventilation flow rate requirements from air quality standards in less than a decade. Join us as we reflect on 100 episodes and look forward to a future where we can judge the success of a space by its ongoing performance, not just minimum standards. HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST:  Max Sherman: https://www.linkedin.com/in/max-sherman-b7301514/ The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.

Welcome back to Air Quality Matters and One Take, where we unpack the latest research shaping our understanding of indoor air and the built environment. The State of Indoor Air in Australia 2025, produced by the Thrive Research Centre and key Australian institutions, represents the first real national stock take of indoor air quality in a country that has been measuring outdoor air for decades. The Shocking Reality: Australia has been producing national state of the environment reports for decades, but they have almost exclusively focused on outdoor air. The great indoors—where Australians spend 90% of their time—has been a massive blind spot. This document is the first real attempt to answer a very simple question: What do we actually know about the air inside our buildings? The answer is a bit of a shock. The Big Takeaway: The most important finding of this report is not about specific pollution levels—it's about the sheer vastness of what we don't know. The report's great contribution is that it authoritatively documents our collective ignorance. It holds up a mirror and shows us a reflection that's mostly blank. This report is intended as a baseline, a starting point, and a catalyst for a national conversation and hopefully a national strategy. After decades of focusing on the sky outside, it's time to finally pay serious, coordinated attention to the air in the rooms we actually live, work, and learn in. This isn't just a report. It's the start of a very important piece of work. https://thriveiaq.com/wp-content/uploads/2025/10/20250909-State-of-Indoor-Air-in-Australia-final.pdf The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: Australia's First Indoor Air Quality Baseline 00:01:35 The Shocking Data Gap: Less Than 0.03% Coverage 00:02:46 Geographic Blind Spots: The Queensland and Western Australia Concentration 00:03:45 Residential Findings: Gas Cookers, Wood Heaters, and Bushfire Smoke 00:04:27 The Hidden Dangers: Formaldehyde and Volatile Organic Compounds 00:05:06 Office Buildings: Traffic Proximity and HVAC Design Matter 00:05:37 The One Take: Documenting Our Ignorance as a Catalyst for Change 00:06:19 Critical Questions for the Future: Building Codes, Infiltration, and Protection 00:07:01 Closing: A Call to Action for Indoor Air Quality

In this landmark episode, we sit down with Dr. Esther Sternberg, a professor of medicine, scientist, and internationally recognized pioneer in the science of mind-body interaction, healing spaces, and the role of place in well-being. Dr. Sternberg's groundbreaking work has influenced how we think about healthy buildings today. Her books—Healing Spaces, The Balance Within, and Well at Work—have become foundational texts for architects, designers, and health professionals seeking to create environments that don't just do no harm, but actively support human flourishing. The Central Question: There's a critical difference between designing spaces to do no harm and designing spaces to support well-being. We have the tools and knowledge to ensure clean air, excellent ventilation, and non-toxic materials—but what about resilience? What about the third leg of the stool: our own capacity to thrive, perform, and heal? Key Topics Discussed: From Immune Response to Environment: Dr. Sternberg's remarkable journey from studying brain-immune connections in rats to discovering how the built environment shapes stress, performance, and health—starting with a single patient and a personal healing experience in Crete. Spirituality in the Workplace: Why this was the hardest chapter to write in Well at Work, and how concepts like flow, focus, rituals, and going offline are essential—not fringe—elements of peak performance and well-being. The Stress-Performance Rainbow: Understanding the relationship between stress and flow. Why the goal is not to eliminate stress, but to find your "middle of the rainbow"—where focus, energy, and performance peak without burnout. Agency and Control: Why giving people choices—over light, sound, temperature, and workspace—is one of the most powerful levers for reducing stress and enhancing resilience. The fighter pilot analogy that explains it all. The Seven Domains of Integrative Health: Sleep, stress and relaxation response, environment, movement, relationships, spirituality, and nutrition—and how each can be embedded into the design and operation of buildings. The GSA Studies: How wearable health devices and continuous environmental monitoring revealed the precise conditions—decibel levels, humidity ranges, light exposure—that optimize health, reduce stress, and improve sleep quality in office workers. Healing Spaces and Virtual Nature: From hospital rooms in Dublin to immersive nature experiences with Studio Elsewhere—how technology and thoughtful design can bring restorative environments to those who need them most. The Contrarian Path: Dr. Sternberg's story of fighting scientific dogma, being denied promotion for work that "had no relevance to human health," and ultimately proving that the brain and immune system are intimately connected—and that place matters profoundly. https://www.linkedin.com/in/esther-sternberg-m-d-8a957927/ https://esthersternberg.com/ HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST: Dr. Esther Sternberg The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. Chapters 00:00:00 Introduction: Meeting Esther Sternberg and the Science of Well-Being 00:02:04 Beyond Do No Harm: Designing Spaces for Well-Being 00:02:32 The Foundation: Clean Air and the 30-Year Cycle of Recognition 00:07:01 Spirituality in Buildings: Focus, Flow, and Belonging 00:12:36 The Science of Flow: Stress, Performance, and the Rainbow Model 00:21:08 Engineering for Performance: Choice, Movement, and Active Office Design 00:25:56 The Athlete Analogy: Building Resilience Through Strategic Stress 00:29:10 Virtual Nature and Reset Spaces: The 15-Minute Dose Effect 00:34:42 Chronic Stress and Burnout: Why Rest is Not Optional 00:34:01 Sustainability of Flow: Body Chemistry and Time Limits 00:56:49 Control and Agency: The Jet Fighter Pilot Lesson 00:58:44 Circadian Light: From Blue to Red and the Morning Advantage 01:02:15 The Given That Isn't: Why Buildings Still Cause Harm 00:38:32 Community and Belonging: The Antidote to Isolation 00:52:26 Acoustics and Culture: The Surprising Variability of Sound Preferences 01:10:09 The Economic Case: Return on Investment for Well-Being 01:18:42 Dr. Sternberg's Journey: From One Patient to the Built Environment 01:29:21 Fighting Dogma: The Politics of Science and Strategic Credibility 01:40:01 The Crete Revelation: Personal Healing and the Seven Domains 01:44:17 GSA Studies: Measuring the Built Environment's Impact on Health 01:53:22 The Future: From Mandates to Magnetic Spaces 01:55:50 Technology and Innovation: From Dublin to Studio Elsewhere 01:58:35 Closing: Building the Army of Advocates

The quality of air in our schools is directly shaping our children's health, attendance, and ability to learn. The Paper:Impact of Air Quality including Thermal Conditions on Educational Buildings on Health, Wellbeing and Performance by Duncan Grassie and researchers from the UK Health Security Agency and Eurovent. This scoping review is essentially a stock take—gathering all existing research to map out what we know, where the evidence is strong, and where the gaps remain. The Fundamental Question: Children spend approximately 30% of their waking hours in educational buildings—breathing air and experiencing thermal conditions they have absolutely no control over. What is the collective evidence telling us about how these environments are shaping their health, attendance, and crucially, their ability to learn? The Paper Impact of Indoor Air Quality, Including Thermal Conditions, in Educational Buildings on Health, Wellbeing, and Performance: A Scoping Review https://doi.org/10.3390/environments12080261 The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website Chapters 00:00:00 Introduction: Understanding Scoping Reviews and Educational Environments 00:01:49 The Three Pillars: Health, Absenteeism, and Performance 00:02:00 Health Impacts: The Respiratory Connection 00:02:50 The Absenteeism Crisis: Quantifying Lost School Days 00:03:46 Academic Performance: The CO2 and Temperature Effect 00:04:56 Solutions Part 1: Source Control as the First Line of Defense 00:05:32 Solutions Part 2: Ventilation as the Critical Intervention 00:06:11 The Economic Case: A $4 Million Investment with $110 Million Returns 00:06:30 The One Take: From Evidence to Action and Our Responsibility 00:07:44 Closing: Thanks and Next Steps

In this essential episode, we dive deep into the complexities shaping the European built environment with an industry expert from Eurovent (YR-VENT), the European industry association for Indoor Climate (HVAC), Process Cooling, and Food Cold Chain technologies. We tackle the core tension in Europe: reconciling the immense pressure for decarbonization with the political and social need for affordable housing. Is the EU's flagship Green Deal facing a legislative backlash? We explore the realities of the 'Fit for 55' package, the polarising effects on national politics (like in Germany), and how geopolitical shifts and inflation are changing market priorities. Key Topics Discussed: The EPBD Shift: Moving from a focus purely on energy consumption to a holistic Sustainable Buildings Directive that integrates Indoor Environmental Quality (IEQ), occupant well-being, solar readiness, and sustainable mobility. IEQ: The Post-Pandemic Reality: Why the massive public awareness of indoor air quality during COVID-19 failed to translate into widespread market changes in schools and residential settings. Smart Systems & Complexity: The future of integrated HVAC systems, the inevitable comparison to complex modern cars, and the new digital skillset required for installers and maintenance personnel. The Risk of "Affordable" Building: A warning against short-sighted construction that focuses on upfront cost, leading to long-term issues like mold and poor health outcomes, and how institutional finance is now demanding IEQ data to mitigate asset risk. Circular Economy & EPDs: The pressing need for the HVAC industry to standardize and harmonize Environmental Product Declarations (EPDs) to accurately calculate embodied carbon and operational carbon for new mandatory building requirements. About Eurovent (YR-VENT): As a coordinating body for the HVAC industry, YR-VENT represents manufacturers across heat pumps, chillers, air filters, and more. We discuss their role in monitoring legislative developments, driving market education, and running the independent third-party performance certification scheme to build confidence in product claims. What are your thoughts on the tension between sustainability and affordability? Let us know in the comments! HOST: Simon Jones: https://www.linkedin.com/in/simon-air-quality-matters/ GUEST: Stijn Renneboog: https://www.linkedin.com/in/stijn-renneboog-42893613b The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon. Chapters 00:00:00 Introduction: Europe's Built Environment at a Crossroads 00:02:39 The Housing Crisis vs Climate Action: Finding Balance 00:17:46 EPBD Evolution: From Energy to Holistic Sustainability 00:25:44 Making the Invisible Visible: Monitoring Indoor Air Quality 00:32:48 Sweden's Success: Ventilation Inspections Drive Energy Renovations 00:35:36 Beyond Minimums: The Market Opportunity for Better Air Quality 00:41:59 Technology Integration: The Promise and Complexity of Smart Buildings 00:48:01 Lessons from Singapore: Separating Conditioning from Ventilation 00:57:03 The COVID Legacy: Why Awareness Didn't Translate to Action 01:09:28 Follow the Money: How Finance is Driving Health in Buildings 01:16:30 Eurovent's Mission: Bridging Policy and Practice 01:32:10 The Embodied Carbon Challenge: Harmonizing Standards for Impact

Welcome back to Air Quality Matters and One Take, where we unpack the latest research and reports shaping our understanding of indoor air and the built environment. This week, I'm diving into the seventh edition of a critical annual report that reads like a global health check—not for people, but for policy. The State of Global Air Quality Funding 2025, produced by the Clean Air Fund and the Climate Policy Initiative, follows the money trail to reveal whether our global investments actually align with our stated goals for clean air, health, and climate action. The diagnosis? It's deeply concerning and frankly contradictory. The Shocking Reality: While the world talks endlessly about the air pollution health crisis, direct funding for outdoor air quality projects has plummeted by 20%, now representing just 1% of all international development funding. Meanwhile, fossil fuel-prolonging funding—money that actively entrenches our dependence on fossil fuels—has surged by 80% in a single year, reaching $9.5 billion. The Contradiction in Action: In 2023, development funders spent more than 2.5 times more money on projects that prolong fossil fuel use than on projects specifically designed for clean air. It's like trying to bail out a sinking boat with a teacup while someone else uses a power drill to punch holes in the hull. Case Study - Bangladesh: A country with some of the world's worst air pollution received $1.1 billion more in fossil fuel-prolonging finance than in all air quality projects combined. The contradiction is staggering. The Glimmer of Hope: Funding for projects with air quality co-benefits—like metro systems or renewable energy where clean air is a happy side effect—rose by 7% to nearly $29 billion. The report argues we need to stop letting clean air be a happy accident and integrate air quality targets into these massive projects from the beginning. The Inequality Crisis: Just three countries (Philippines, Bangladesh, China) received 65% of all direct outdoor air quality funding. Meanwhile, of the 10 countries with the world's highest PM2.5 concentrations, seven received less than $1 per person in total air quality financing. Sub-Saharan Africa's situation is particularly dire, with funding dropping by 91% and now receiving less than 1% of the global total. The Fundamental Question: This report isn't just a collection of data—it's a mirror held up to our global priorities. And right now, that reflection shows a world trying to treat a disease with one hand while actively feeding it with another. Air pollution isn't just an environmental or health issue, but a fundamental development challenge. The question this report leaves us with: What are we going to do to change the picture? The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website.

I sit down with two of the most influential actors in the indoor air quality sector, Georgia Lagoudas (Science Policy Expert and Bioengineer) and Bronwyn King (Australian Radiation Oncologist & Anti-Tobacco Campaigner), the principals behind the recent landmark air quality event at the UN General Assembly in New York. This event launched the Global Pledge for Healthy Indoor Air—the first international effort to formally recognise clean indoor air as a basic human right essential to health and well-being. In this powerful conversation, they break down: The Problem: Why, despite all the science and technology, we still don't have clean air in our schools, hospitals, and workplaces. The Water Analogy: How we expect clean water but accept unsafe air. The 6 Pillars of the Pledge: How clean indoor air stitches into Human Rights, Health, Pandemic Preparedness, Climate Resilience, Workplace Safety, and Inclusion. The Cost of Inaction: Why the long-term health impact of poor indoor air is comparable to tobacco exposure. The Future: How Air Club and the Global Pledge plan to create "Fear Of Missing Out" among governments and organisations to drive real change. Join the Movement & Take Action:  https://www.airclub.org/ GUESTS: Georgia Lagoudas: https://www.linkedin.com/in/georgialagoudas/ Bronwyn King: https://www.linkedin.com/in/bronwyn-king The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. Chapters 00:00:00 Introduction: The Global Pledge for Healthy Indoor Air 00:02:30 Why a Pledge and Why Now 00:05:46 Creating Global Solidarity Through Advocacy 00:21:13 Air Quality as a Fundamental Human Right 00:22:56 Health Impacts: Beyond the Lungs 00:23:48 Pandemic Preparedness and Building Resilience 00:25:16 Climate Resilience and Wildfire Smoke 00:26:36 Workplace Safety and Accessibility Rights 00:38:38 The Invisibility Problem and Communication Challenge 00:47:05 Economic Impacts and the Cost of Inaction 01:03:18 Taking Action: From Pledges to Practice 01:10:53 Building the UN Coalition 01:19:10 Air Club and the Path Forward

Does fixing ventilation in homes actually make people with asthma healthier? The answer is an emphatic yes – but the type of system you install makes all the difference. This episode unpacks a remarkable two-year study from Chicago that followed 51 adults with physician-diagnosed asthma across 40 homes, tracking their health before and after different ventilation interventions. The researchers didn't just install equipment and hope for the best – they meticulously measured asthma control month by month using standardized health scores, while simultaneously monitoring indoor air pollutants to understand exactly what was changing. The results are striking. Across all intervention types, participants saw a 6.3% improvement in asthma control scores – enough to shift the proportion of people with well-controlled asthma from 57% to 75%. But here's where it gets fascinating: the gold standard balanced ventilation systems with energy recovery (MVHR/ERV) delivered an 8.4% improvement, pushing 86% of participants into well-controlled territory and eliminating poorly controlled asthma entirely in that group. Meanwhile, simpler exhaust-only systems still helped but delivered less than half the benefit. The Smoking Gun: Nitrogen Dioxide The study identified a clear culprit: nitrogen dioxide from gas cooking. For every standard deviation decrease in indoor NO2 levels, asthma control improved by 7.1%. In a study where 90% of homes had gas stoves, this finding directly links the pollutants we generate indoors to measurable health outcomes. It's not just about bringing in fresh air – it's about diluting and removing the combustion byproducts that accumulate in our homes. Perhaps most powerfully, the greatest improvements occurred among those who needed it most: participants over 45, Black and African American residents, and households earning less than $75,000 annually. These groups started with worse asthma control, meaning the intervention delivered its biggest impact precisely where health disparities are greatest. From Building Codes to Therapeutic Environments This isn't just another academic exercise – it's real-world evidence that transforms how we think about home ventilation. The study shows that properly designed mechanical ventilation isn't a luxury or just about meeting codes; it's a direct public health intervention that can reduce health inequalities. The benefits aren't immediate – they build over months and years – but they're substantial and measurable. The implications are profound. When a ventilation upgrade can eliminate poorly controlled asthma in a group of sufferers, we're not talking about marginal gains. We're talking about transforming homes from environments that exacerbate illness into therapeutic spaces that actively support health. And crucially, this intervention works best for those who are suffering most – offering a concrete pathway to address health equity through better housing. This research moves us beyond theoretical arguments about air quality to hard evidence: engineering our indoor environments is healthcare by another name. For the millions living with asthma, especially in communities already facing health disparities, this study offers hope that relatively straightforward home improvements can deliver life-changing results. Effects of residential ventilation and filtration interventions on adult  asthma outcomes The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.

In this special episode, we sit down with the founders and champions of World Ventilate Day (November 8th) to dissect the critical difference between air quality and ventilation. They reveal why their focus is on action, agency, and empowering everyone—from homeowners to governments—to take control of their indoor environments. Key Discussion Points: Action vs. Nuance: Why the day focuses on ventilation (the action) rather than the more nuanced conversation around air quality. The Agency Angle: How ventilation provides agency at every level, from national governance to managing your own home. Beyond Air Quality: Why ventilation is critical not just for air, but for managing a building's thermal environment, humidity, comfort, and energy. The Pandemic's Legacy: The shocking realisation during COVID that "we haven't got a clue" about the ventilation in our buildings, and the danger of apathy today. The Collaboration Imperative: Discussing the theme 'Collaborate to Ventilate' and the need for engineers and building users to work together. What We're NOT Talking About: The panellists share their most pressing overlooked topics, including the destructive power of apathy , the complexity of real-world ventilation , and the urgent need for competence and accountability in the industry. Reframing Success: Why we need to measure the performance and outcomes of ventilation, not just the existence of a product. Chapters 00:00:00 Introduction: World Ventilate Day and Its Mission 00:02:25 Why Ventilation, Not Just Air Quality? 00:06:25 The Origins: How World Ventilate Day Began 00:09:02 The Pandemic Wake-Up Call: What We Didn't Know 00:17:10 Breaking Down Engineering Barriers Through Collaboration 00:21:56 Ventilation Engineers: The Hidden Health Heroes 00:23:45 The Lungs as Filters: A Powerful Analogy 00:28:57 The Future of World Ventilate Day: Going Global 00:34:21 Fighting Apathy: The Destructive Power of Indifference 00:38:12 The Complexity Challenge: Beyond Simple Solutions 00:43:52 The Competence Crisis: When Good Intentions Go Wrong 00:49:16 Reframing Success: From Products to Performance World Ventilate Day: November 8th.  Find out more and get involved: https://www.worldventil8day.com/ Cath Noakes Henry Burridge Nathan Wood #81 - Nathan Wood #15 Cath Noakes #7 Henry Burridge The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website.

Why is it so difficult to prove that mold makes people sick when millions of people clearly suffer in water-damaged buildings? The association is undeniable. The causation? That's where things get complicated. This episode unpacks a fundamental challenge that has plagued the mold and health field for decades – the seemingly simple but scientifically complex distinction between association and causation. We know with certainty that people in damp, moldy buildings experience more respiratory symptoms, asthma exacerbations, and various health complaints. The 2004 Institute of Medicine report established this definitively, finding "sufficient evidence of an association" between visible mold and respiratory symptoms. But proving that mold directly causes these problems? That's an entirely different scientific mountain to climb. The core challenge lies in what scientists call the Bradford Hill criteria – the gold standard for establishing causation in epidemiology. To prove mold causes illness, we'd need to demonstrate a clear dose-response relationship (more mold equals more illness), temporal relationships (exposure before symptoms), biological plausibility, and ideally, experimental evidence. But here's the rub: mold exposure in real buildings is never just mold exposure. It's a complex soup of fungal spores, bacterial endotoxins, volatile organic compounds, allergens, and chemical emissions from degrading materials. How do you isolate the effect of one component in this biological cocktail? The Exposure Assessment Black Hole Perhaps the most maddening aspect is our inability to accurately measure what people are actually exposed to. Unlike a drug trial where you know exactly what dose someone received, mold exposure is invisible, variable, and cumulative. A single air sample tells you almost nothing about someone's exposure over weeks or months. Spore counts fluctuate wildly based on humidity, disturbance, and time of day. Some people might react to dead spores or fragments that don't even show up in standard tests. Others might be sensitive to mycotoxins at levels far below what we can reliably detect. This measurement problem creates a vicious cycle. Without good exposure data, we can't establish dose-response relationships. Without dose-response relationships, we can't prove causation. Without proven causation, there's less funding for better measurement tools. And round and round we go. The Human Variability Factor Then there's the inconvenient fact that people react differently to the same environment. Genetics, immune status, age, pre-existing conditions – all these factors influence whether someone develops symptoms in a moldy building. This heterogeneity makes it nearly impossible to predict who will get sick and how sick they'll get, further muddying the causation waters. The episode explores how this scientific uncertainty has real-world consequences. Insurance companies exploit the causation gap to deny claims. Building owners hide behind the lack of "proof" to avoid remediation. Meanwhile, people suffering in water-damaged buildings are told their symptoms might be "all in their head" because science can't definitively prove the mold is making them sick. The Path Forward Despite these challenges, the scientific consensus is clear on one point: water-damaged buildings are unhealthy environments that should be remediated, regardless of whether we can prove specific causal pathways. The precautionary principle applies – we know enough about the associations to act, even if we can't draw straight lines from exposure to illness. This One Take reveals why the mold and health field remains so contentious and why simple questions like "is mold making me sick?" don't have simple answers. It's a sobering reminder that in environmental health, the gap between what we observe and what we can scientifically prove often feels insurmountable – not because the connections aren't real, but because reality is far more complex than our measurement tools and study designs can capture. Damp Indoor Spaces and Health (2004) The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.

When Worlds Collide: Tropical Wisdom Meets Temperate Challenges In this wide-ranging discussion, Chandra brings over 35 years of experience from Singapore's hot, humid environment to share insights that challenge conventional thinking about ventilation and comfort. As one of three pioneers who established Singapore's indoor air quality research unit in the early 1990s, his team's tagline – "energy efficient, healthy buildings" – has guided decades of innovation in tropical building design. The conversation reveals striking contrasts: while European buildings might operate at 21-23°C, Singapore's newest net-zero buildings maintain comfort at 26-27°C using elevated air speeds from ceiling fans. This isn't just about energy savings – it's a fundamental rethinking of how we achieve thermal comfort. As Chandra explains, tropically-acclimatized people actually prefer air movement, unlike those from colder climates who perceive it as draft. Chapters 00:00:00 Introduction: Meeting a Legend of Indoor Air Quality 00:02:08 Air Quality as a Human-Centered Challenge 00:23:17 Making the Invisible Visible: Sensors and Awareness 00:42:58 Hot and Humid Climates: Engineering Lessons from Singapore 00:52:50 Decoupling Ventilation from Cooling: A Revolutionary Approach 01:00:55 Net-Zero Buildings and Adaptive Comfort 01:12:25 Global Equity and Simple Solutions 01:23:30 Building Preparedness and Future Resilience Chandra Sekhar - LinkedIn https://www.linkedin.com/in/professor-chandra-sekhar-singapore/ The Air Quality Matters Podcast in Partnership with Zehnder Group -  Farmwood - Eurovent- Aico - Aereco - Ultra Protect -  The One Take Podcast in Partnership with SafeTraces and Inbiot Do check them out in the links and on the Air Quality Matters Website. If you haven't checked out the YouTube channel its here. Do subscribe if you can, lots more content is coming soon.