2021 International Mechanical Code – IMC-2021

The 2021 International Mechanical Code® (IMC) establishes minimum standards for the design, installation, and maintenance of mechanical systems in residential, commercial, and industrial buildings. Covering everything from HVAC and ventilation to boilers and refrigeration, the IMC ensures safe, efficient, and code-compliant system operation. Fully coordinated with the 2021 I-Codes.

Highlights:

• Updated rules for appliance access, clearances, condensate drainage, and temperature control
• Comprehensive ventilation standards for occupied and unoccupied spaces, including hospitals and hazardous locations
• Detailed exhaust system requirements for kitchens, dryers, labs, garages, and smoke/grease control
• Regulates duct construction, dampers, insulation, filters, and fire/smoke control systems
• Refers to NFPA and IFGC standards for combustion air; includes chimney and flue guidance
• Covers installation standards for fireplaces, cooking appliances, sauna heaters, and fuel cells
• Includes safety and design rules for boilers, pressure vessels, relief valves, and tanks
• Establishes refrigeration system classification, design, piping, and testing procedures
• Provides hydronic system guidance for hot/chilled water piping, antifreeze, and insulation
• Sets safety standards for fuel oil piping, storage, and solar thermal systems
• Appendices include permit fee schedules, chimney diagrams, and appeal procedures

Who It’s For:
Mechanical contractors, engineers, inspectors, and HVAC professionals working on code-compliant building system design, installation, and maintenance.

IMC-2021