What is the function of a thermostat in HVAC systems?

The function of a thermostat in HVAC systems is to regulate temperature. It serves as a control device that monitors the ambient temperature of a space and maintains it at a set level that is comfortable for occupants. When the temperature deviates from the desired set point, the thermostat sends signals to the heating or cooling system to either turn on or off, thereby adjusting the temperature accordingly. This helps ensure that indoor environments remain comfortable while also providing energy efficiency by preventing unnecessary heating or cooling.

While the other options describe important functions in HVAC systems, they do not pertain to the primary role of the thermostat. For example, air filtration is performed by filters, humidity measurement is done by hygrometers, and airflow control is managed by dampers and fans. The unique purpose of a thermostat is centered around temperature regulation, making it essential for maintaining desired climate conditions within a building.