The heating, ventilation, and air

HVAC System: The heating, ventilation, and air
conditioning (HVAC) system includes any interior
surface of the facility’s air distribution system for
conditioned spaces and/or occupied zones. This
includes the entire heating, air-conditioning, and
ventilation system from the points where the air enters
the system to the points where the air is discharged from
the system. The return air grilles, return air ducts to the
air-handling unit (AHU), the interior surfaces of the AHU,
mixing box, coil compartment, condensate drain pans,
humidifiers and dehumidifiers, supply air ducts, fans, fan
housing, fan blades, air wash systems, spray
eliminators, turning vanes, filters, filter housings, reheat
coils, and supply diffusers are all considered part of the
HVAC system. The HVAC system may also include
other components such as dedicated exhaust and
ventilation components and make-up air systems