Furnaces circulate air across a heat exchanger with a blower or a fan and distribute the heated air throughout the building using a series of ducts. Energy efficient furnaces can feature a secondary heat exchanger, electronic ignition, sealed combustion and pulse combustion. Conventional Unit Heaters are also forced air space heaters. Unit heaters are typically used in warehouses, garages or manufacturing facilities. They are normally ceiling mounted, and discharge the air directly into the space.
Standard units have pilots and are gravity vented.
Energy efficient units feature electronic ignition and power venting. Radiant Heaters or Infrared Heaters, are typically used in warehouses and garages, and in drafty locations where doors are opened frequently. Infrared systems heat the objects, the floor and people beneath heating units. Absorbers use water as the refrigerant, completely eliminating the need for CFCs, which are known to damage the ozone layer of our atmosphere. Absorption chillers have few moving parts, so operation is quiet and vibration-free.