Code Compliance
International Mechanical Code (IMC), International Residential Code (IRC), ASHRAE standards, EPA Section 608 requirements, and permit/inspection processes for HVAC installations.
- Identify the scope and purpose of the IMC, IRC, and ASHRAE standards relevant to HVAC
- Describe EPA Section 608 certification requirements, refrigerant handling rules, and the AIM Act R-410A new-equipment ban effective January 1, 2026
- Explain the permit and inspection process for HVAC installations and replacements
- Apply code requirements for equipment clearances, combustion air, and venting
Lección 1
Mechanical Codes - IMC, IRC, and Local Amendments
The Code Hierarchy
HVAC installations in the United States are governed by a hierarchy of codes and standards. Understanding which code applies and how they interact is tested on the CHP-5 exam.
The International Code Council (ICC) publishes model codes that jurisdictions adopt. The two most relevant for HVAC are:
- International Mechanical Code (IMC): Governs HVAC systems in commercial buildings. Covers equipment installation, ductwork, piping, combustion air, exhaust systems, and hydronic heating.
- International Residential Code (IRC): Chapter M12-M24 governs HVAC systems in one- and two-family dwellings and townhouses. For most residential HVAC work, the IRC is the applicable code.
Local jurisdictions (cities, counties, states) adopt these model codes and may add local amendments that are more restrictive. A technician must follow whichever requirement is most stringent - the model code or the local amendment.
IMC - Commercial
Scope: Commercial, industrial, institutional buildings
Publisher: International Code Council (ICC)
Covers: Mechanical equipment, ductwork, piping, ventilation
Enforced by: Local building department
IRC - Residential
Scope: One/two-family dwellings, townhouses
Publisher: International Code Council (ICC)
Covers: HVAC chapters M12-M24
Enforced by: Local building department
ASHRAE Standards
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) publishes standards that are often referenced within the IMC and IRC:
- ASHRAE 62.1 - Ventilation for Acceptable Indoor Air Quality (commercial buildings)
- ASHRAE 62.2 - Ventilation and Acceptable Indoor Air Quality in Residential Buildings
- ASHRAE 90.1 - Energy Standard for Buildings (commercial - sets minimum efficiency requirements)
- ASHRAE 15 - Safety Standard for Refrigeration Systems (refrigerant charge limits, machinery room requirements)
- ASHRAE 34 - Designation and Safety Classification of Refrigerants (the A1, A2L, A3 classification system)
ASHRAE standards are not codes by themselves - they become enforceable only when adopted by reference in the applicable building code.
The IMC governs commercial HVAC and the IRC governs residential HVAC. Local jurisdictions may add amendments that are more restrictive than the model code - always follow the most stringent requirement. ASHRAE standards (62.1, 62.2, 90.1, 15, 34) become enforceable when referenced within the adopted building code.