Air-Handler Smoke Dampers

Q: What is the amount of air delivery (in CFM) that an air handler needs to have before it is required to have a smoke damper on the discharge of the air-handler?

 A: Section 19.5.2.1 of the 2000 edition of the Life Safety Code requires compliance with section 9.2 concerning utilities. Section 9.2.1 requires compliance with NFPA 90A Standard for the Installation of Air-Conditioning and Ventilation Systems (1999 edition) for all air-conditioning, heating and ventilation equipment.  NFPA 90A section 2-3.9.2 says smoke dampers must be installed in (air handler) systems with a capacity greater than 15,000 cubic feet per minute (CFM) to isolate the air-handling equipment, including filters, from the remainder of the system in order to restrict the circulation of smoke. However, there are some exceptions to this requirement that you may qualify for:

  • Where the air-handling unit is located on the floor that it serves and serves only that floor, and;
  • Where the air-handling unit is located on the roof and serves only the floor immediately below the roof, then smoke dampers are not required on the air-handling equipment.

It is recommended that you contact your state and local authorities to determine if they have other requirements that you must follow.