06 - Air Distribution System Types

Send us Fan MailUnderstand duct categories, materials (sheet metal, duct board, flex duct), proper design, sealing, and common installation defects.Show Notes:Episode Overview: Compare duct categories (low pressure/low velocity vs. high pressure/high velocity), typical design goals (Manual J for loads, Manual D for duct sizing), duct materials (sheet metal, duct board, flex duct), sealing and securing practices, return air considerations, transfer/jumper ducts, multi-story distribution challenges, and common installation defects (sagging, leaks, improper connections, return plenums).What You'll Learn: • Duct categories: low pressure/low velocity vs. high pressure/high velocity • Design standards: ACCA Manual D for duct sizing • Duct materials: sheet metal, duct board, flex duct (pros/cons of each) • Sealing and securing: mastic, foil tape (not cloth duct tape), proper support • Return air systems: transfer ducts, jumper ducts, return grilles • Multi-story distribution challenges and damper use • Common defects: sagging flex duct, unsealed joints, improper splicing, undersized returnsKey Takeaways: ✓ Identify duct types and materials ✓ Recognize proper duct installation and support ✓ Spot common duct defects that affect system performanceIRC Code References: IRC 2018 M1601 (Duct Systems); ACCA Manual DStudy Tips: Inspect ductwork in attics and crawl spaces. Note materials, support methods, and sealing quality.Intro This episode is brought to you by GetSync.pro This episode is hosted by Charlie Bellefontaine of Chicagoland Home InspectorsFor complete training with visual materials, practice exams, and certification support, visit nhiexamprep.com© 2025 National Home Inspector Exam Prep Podcast. All rights reserved.