A HVAC air handler is a device used to condition and circulate air as part of a heating, ventilation, and air conditioning (HVAC) system. It is typically a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers. The air handler is connected to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the air handler. The air handler also circulates air within the building and is responsible for the air quality and temperature control. The air handler is usually located in the attic, basement, or garage, and is connected to the HVAC system’s thermostat, humidistat, and air filter. It is responsible for moving air in and out of the building, as well as controlling the temperature and humidity levels. It is also responsible for filtering out dust, pollen, and other airborne particles.