What role does the outdoor unit play in an air-conditioning system?

The outdoor unit in an air-conditioning system primarily functions for cooling. It is responsible for dissipating the heat absorbed from indoor air and transferring it outside. This process is essential in creating a temperature differential that allows the indoor air to become cooler. The outdoor unit usually contains components such as the compressor and condenser, which are critical in the refrigeration cycle that enables cooling.

In cooling mode, the heat absorbed by the evaporator coil inside the building is circulated to the outdoor unit, where the compressor increases the refrigerant's pressure and sends it to the condenser coil. Here, the refrigerant releases its heat to the outside air.

While some outdoor units can be part of systems that offer heating (such as heat pumps), the primary function of an air-conditioning system's outdoor unit, in a standard cooling scenario, is to facilitate the transfer of heat out of the space being cooled. Therefore, identifying its role correctly as that of cooling is essential for understanding how the overall HVAC system operates.