How does a heat exchanger function in a heat pump system?

A heat exchanger plays a crucial role in a heat pump system by transferring heat between the refrigerant and either air or water. In a heating mode, the heat exchanger allows the refrigerant to absorb heat from the environment (air or water) and carry it into the home. This process involves the phase change of the refrigerant, where it evaporates by absorbing heat, and later condenses in the system, releasing that heat inside the building.

When a heat pump operates in cooling mode, the process is reversed. The heat exchanger releases heat from the refrigerant into the outside air or water, allowing the refrigerant to cool down as it condenses. This efficient transfer of heat is what enables heat pumps to provide both heating and cooling, making them versatile systems for temperature regulation in residential and commercial settings.

In contrast, other options do not accurately describe the function of a heat exchanger. Adding refrigerant to the system is managed by other components such as the expansion valve. Storing excess refrigerant is also not a function of the heat exchanger, as its primary role is active heat transfer rather than storage. Increasing the temperature of condensate does not align with the heat exchanger's purpose, which is focused on transferring heat rather than altering the state or temperature