Which component directly contributes to the absorption of heat from the outside air in an air-to-air heat pump?

In an air-to-air heat pump, the outdoor coil plays a crucial role in the absorption of heat from the outside air. This component is designed to act as an evaporator when the heat pump is in heating mode. As the refrigerant flows through the outdoor coil, it absorbs thermal energy from the outside air, even when temperatures are low. This occurs because refrigerants have a low boiling point, allowing them to evaporate and absorb heat at relatively low temperatures.

The outdoor coil is placed in the external environment and is specifically engineered to maximize contact with the outdoor air, enhancing heat exchange. The absorbed heat is then carried into the system where it can be further compressed and transferred into the indoor space for heating purposes.

Understanding this process is fundamental in grasping how air-to-air heat pumps function efficiently, especially in varying climatic conditions. Other components in the heat pump, while essential for the overall operation, do not serve the specific function of heat absorption from the outdoor environment in the same way that the outdoor coil does.