What does a humidistat control in an HVAC system?

A humidistat plays a critical role in managing the humidity levels within an HVAC system. By detecting the amount of moisture in the air, a humidistat regulates the operation of humidifiers or dehumidifiers to maintain desired humidity levels. Proper humidity control is essential for comfort, health, and the prevention of damage to the building structure and furnishings.

In contrast, a thermostat specifically handles temperature settings rather than humidity. Airflow direction is managed by dampers and fans, which do not concern humidity levels directly. Dust filtration is the responsibility of air filters that clean the air but do not influence humidity. Hence, the primary function of a humidistat is to ensure that humidity is controlled effectively in an HVAC system, making it clear why it is the accurate choice in this context.