What is one primary role of a chiller in an HVAC system?

The primary role of a chiller in an HVAC system is to lower the temperature of liquids used in the system. Chill water systems are essential in maintaining the desired indoor climate by absorbing heat from the building's air and then transferring that heat away from the space. The chiller accomplishes this by using refrigerants, which change from a liquid to a gas in a closed loop system, thereby extracting heat and cooling the water that is then circulated through air handling units to provide cooling to the occupied spaces. This process is crucial in large commercial applications, where maintaining specific temperature and humidity levels is vital for comfort and efficiency.

The other roles listed are not functions of a chiller. Heating air is typically done by boilers or heating systems, circulating warm water is not a function associated with chillers but rather with heating systems, and removing water vapor from the air is a task carried out by dehumidifiers or cooling systems that involve air conditioning processes, rather than by the chiller itself.