Air Handlers Information

Air handlerAir handlers regulate and circulate air in HVAC systems. They typically consist of a blower, a heat exchange medium for heat or air conditioning, and housing. An air handler unit is the main component of an air conditioning system. An air-handler unit includes:

  • various dampers
  • air filter
  • heating and cooling coils
  • fan

Dampers control the flow of outside air, return air, and mixed air. The air filter removes dust particles from the air, heating and cooling coils condition the air, and the fan delivers the conditioned air to various parts of the building. Air handling effectively circulates conditioned air throughout a space. When matched with a heat pump, air handling circulates both cool and hot air, depending on the season.


There are several types of air handlers. Examples include:

  • HVAC air handlers
  • air filter handlers
  • hot water air handlers

HVAC stands for heating, ventilation, and air conditioning. These three functions of HVAC air handlers are closely interrelated and control the temperature and humidity of the air within a building. Air filter handlers remove dust from an air stream as the dust-laden air passes through them. Hot water air handlers consist of a hot water coil, the air handler, a condenser and/or furnace, and a water heater or boiler. Other air handlers are commonly available.


There are several ways in which air handlers function. Air handlers are used for both commercial and residential purposes. A commercial air handler is normally a very large system moving 2,000 CFM to 10,000 CFM and higher. A commercial air handler may be mounted on a roof or in large mechanical rooms located in a building. A commercial air handler has an economizer or inlet damper that allows for a small amount of outside air, or make-up air, to be pulled in through the air handler. In an air handler residential system, heat pumps or air conditioners along with air handlers compile a quality heating and cooling system, which can be installed for non-commercial purposes. All air handlers are designed to move a certain amount of air (in both the heating and cooling modes) at an approximate pressure drop. For example, a 3-ton heating/cooling system may be designed to move up to 1,200 CFM at a total system static pressure of 0.5 inches (w.g.) with a half HP motor. Air handlers are designed and manufactured to meet most industry specifications.


Air handlers are used in many applications. For example, they can be used for providing smoke control, maintaining pressure relationships between spaces, and providing fresh air for occupants. Air handlers provide heating, cooling, ventilation, and humidity control for a building.


Air handlers should adhere to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards to provide decent air filtration and to protect heating and cooling systems equipment without adding much in static pressure or pressure drop.

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