What is the role of the outdoor unit in an air-to-air heat pump system?

The correct role of the outdoor unit in an air-to-air heat pump system is to contain the compressor and condenser, which are crucial for the heat exchange process. The compressor is responsible for circulating the refrigerant and increasing its pressure, which allows it to absorb heat from the outside air even when temperatures are low. The condenser, on the other hand, releases the absorbed heat into the indoor environment. This process is essential for transferring warmth into the home during colder months and is central to the efficient operation of the heat pump.

The outdoor unit does not house heating elements, as those are typically found in the indoor unit. While filtering air is important, this function is primarily carried out by filters located indoors. Additionally, while some systems may use supplemental heating, the outdoor unit itself is not a backup heat source but rather a critical component for the heat exchange necessary for the heat pump’s operation. The outdoor unit's design and function are vital for the overall efficiency and effectiveness of the heat pump system.