NFPA 90B 2021 Standard for the Installation of Warm Air Heating and Air-Conditioning Systems

The NFPA 90B Standard provides guidelines for the installation, operation, and maintenance of warm air heating and air-conditioning systems in one- and two-family dwellings or buildings under 25,000 cubic feet. It ensures fire safety, proper ventilation, and efficient system performance in residential and small commercial settings.

This standard covers:

• Ductwork and insulation requirements to prevent fire hazards.
• Air distribution systems for safe and effective heating and cooling.
• Installation guidelines for HVAC components.
• Maintenance protocols to ensure long-term safety and efficiency.

About NFPA

NFPA is known as the trusted source of safety knowledge, the National Fire Protection Association (NFPA) has been helping to solve some of the planet’s toughest safety problems for more than 125 years. To remain relevant for over a century as a knowledge and information organization, we’ve continually evolved our scope of expertise—from fire prevention, wildfire preparedness, and electrical safety to hazardous materials, community risk reduction, and public safety.

Other Works:

• NFPA 72: National Fire Alarm and Signaling Code, 2022 Edition 
• NFPA 90A: Standard for the Installation of Air-Conditioning and Ventilating Systems, 2012 Edition  
• NFPA 101, Life Safety Code 2024