What is a heat exchanger used for?

A heat exchanger is a device designed to transfer heat between two or more fluids while keeping them separate. It efficiently moves heat energy from one fluid to another, which is essential in various HVACR applications. For instance, in a heating system, it allows the transfer of heat from hot water to the air distributed throughout a building without mixing the water and air.

This ability to effectively transfer heat is what makes heat exchangers fundamental in many systems, such as boilers, chillers, and air conditioning units. They help in optimizing energy consumption and ensuring temperatures are maintained at desired levels efficiently.

The other options focus on functionalities that do not align with the primary purpose of a heat exchanger. For example, separating air and water, cooling refrigerants, and compressing gases involve different mechanisms or components within HVACR systems. Thus, the main role of a heat exchanger as a medium for moving heat energy between fluids is what justifies its use and importance in HVACR practices.