Summary

• Manufacturers must comply with NAECA, so HVAC equipment purchased by builders should automatically comply with code requirements.
• The 2003 IECC has minimum insulation thicknesses for HVAC piping by type of piping system, pipe size, and fluid temperature range.
• Duct insulation requirements in the IECC depend on the type of duct and the location of the ducts.
• All duct joints, seams, and connections must be securely fastened with welds, gaskets, mastics (adhesives), mastic-plus-embedded-fabric, or tapes. "Duct tape" is not permitted.
• Air economizers are required in some locations and circumstances.