How an air-to-air heat pump works

Heat is transferred by refrigerant

The outdoor unit absorbs heat from the outside air. Refrigerant circulates between the outdoor and indoor units in a closed system. The compressor raises its pressure and temperature so the heat can be released indoors, after which the cycle continues.

The air contains heat energy even when it is cold, but the heat pump's output and efficiency are affected by the outdoor temperature. The model therefore needs to be selected for the building and the conditions in which it will be used.

The indoor unit distributes the air

A fan distributes the heated air through the building. Placement, open passages and the layout affect how the heat reaches different rooms. An air-to-air heat pump heats indoor air and does not produce domestic hot water.

Many models can also provide cooling. In that mode, heat is transferred from the building to the surroundings. Follow the instructions for the operating modes supported by your model.

Installation and maintenance affect performance

The heat pump needs the right placement and correct installation to work as intended. Filters and airways must be kept clean. Regular checks and professional maintenance help identify anything that needs attention.