Codes, Standards, and Documentation
The Codes, Standards, and Documentation domain tests whether you know which rules govern an air distribution installation and what paperwork proves compliance. Items cover the IMC and IRC, ASHRAE standards, Manual J and Manual D, SMACNA, UL 181, NFPA 90A/90B, permits, submittals, and closeout documents.
Core rules and concepts
- The International Mechanical Code (IMC) and International Residential Code (IRC) set minimum duct construction, clearance, and ventilation requirements; local amendments control.
- ASHRAE 62.2 addresses residential ventilation; ASHRAE 90.1 and the IECC address energy and duct insulation.
- ACCA Manual J, S, and D are the accepted load, equipment, and duct design methods for residential systems.
- SMACNA standards govern duct construction and leakage classes; UL 181 governs flexible duct and closure systems.
- NFPA 90A and 90B apply to air-handling and exhaust systems. Keep submittals, calculations, test reports, and as-builts.
Worked example
A plan reviewer rejects a residential duct plan because it shows a friction rate but no load calculation or equipment selection. The contractor submits a room-by-room Manual J, a Manual S equipment match, and a Manual D layout with TEL and ASP. The reviewer can now verify that the duct size matches the actual load.
Traps that cost marks
Treating manufacturer instructions as optional, citing a standard without the local amendment, and submitting a TAB report without design values. Another is failing to keep approved submittals and as-built drawings, which makes final inspection and future service harder.