What does the "chiller" accomplish in an HVAC system?

The correct function of a chiller in an HVAC system is to remove heat from a liquid, typically water or a refrigerant, which is then circulated throughout the system. This process is crucial for cooling the air within a building. The chiller operates on the principles of thermodynamics, where it absorbs heat from the liquid and transfers it elsewhere (often to a heat exchanger or cooling tower) to reject it outside the building.

This function allows the HVAC system to lower the temperature of the air that is then circulated through the ducts to cool the interior spaces. It is important to understand that while chillers may be part of a larger system that manages humidity or air distribution, their primary role is in the heat removal process.

The other options focus on different functions: heating air, moisture removal, and air circulation, which are typically handled by other components of the HVAC system rather than by the chiller itself.