Heating and cooling systems are an essential modern convenience. However, in the event of a fire, flames, heat, smoke, and gases can quickly spread through heating, ventilation, and air-conditioning (HVAC) systems. NFPA 90B, Standard for the Installation of Warm Air Heating and Air-Conditioning Systems, provides comprehensive requirements for the construction, installation, operation, and maintenance of systems for warm air heating and air conditioning, including filters, ducts, and related components.

The standard applies to indoor HVAC systems, components, and air distribution in one- and two-family dwellings and all buildings under 25,000 cubic feet in volume. Topics covered include:

• Integration of ventilation and air-conditioning system(s) with building construction
• Fire integrity of building construction
• Equipment, wiring, and controls, including temperature limit controls and fan controls

Key Features and Benefits of NFPA 90A-2027 Include:

• New Requirement in Section 4.2: An exception was added for materials made of certain noncombustible materials to be exempt from the testing requirement.
• Updates Reference Document for Noncombustible Material Criteria: References NFPA 5000^®, Building Construction and Safety Code^®, for the noncombustible material criteria within Chapter 4, instead of NFPA 101^®, Life Safety Code^®.
• Revised References: References were updated to the most recent editions of NFPA codes and standards and other referenced publications.
• NFPA Manual of Style (MOS) Updates: Changes were made for compliance with the MOS, which improves clarity and usability of the standard.