Attic Air Conditioner Components

Air Handler

• Attic air conditioners depend on furnace or air handler units to draw warm air in and send cool air out through supply ducts and registers. Drain hoses running alongside the air handler release excess water through a condensate drain. Air handlers are located in the attic itself.

Evaporator Coil

• The evaporator coil is part of the air handler unit. This AC component converts liquid refrigerant to gas form. Gas cools the evaporator coil, which then cools and dehumidifies air blowing across the evaporator. The warmed gas is eventually returned to the condensing unit.

Condenser

• Condensers are typically located outside the home on the roof. These condensing units consist of a condenser coil, fan, compressor and refrigerant lines.

Compressor and Refrigerant Lines

• The compressor in the condensing unit is responsible for sending cooled liquid refrigerant via refrigerant lines to the evaporator coil. Refrigerant lines transfer refrigerant in pipes running between the air handler and condensing unit. These pipes are usually made of copper and are separate from the evaporator coil. The refrigerant lines send warmed refrigerant gas back to the condenser, where the fan releases the heat outside the home.

Exceptions

• Some attic air conditioning units do not contain air handlers with ducts that distribute cool and warm air in homes. Instead, the unit contains the indoor fan and evaporator coil, which dehumidify and cool air. Similar to attic AC units with air handlers, these ductless systems utilize refrigerant lines to send liquid refrigerant to outside condensing units.

Considerations

• Attic AC units are often installed horizontally rather than vertically due to limited space and low ceilings in attics. Installing AC equipment or ductwork in damp, wet or moldy attic spaces can negatively affect indoor air quality. Air handlers located in cramped attic spaces can hamper access to equipment during routine maintenance and repairs.