What do thermostats primarily control in a residential HVAC system?

Thermostats primarily control temperature within a residential HVAC system. They function as a setpoint for the desired indoor temperature and signal the HVAC system to heat or cool the space accordingly. When the ambient temperature deviates from the setpoint, the thermostat activates the heating or cooling equipment to maintain comfort levels. This direct control over temperature is crucial for ensuring a comfortable living environment, which is the primary function of residential HVAC systems.

While thermostats can have secondary effects on other factors, such as energy consumption and humidity regulation, their core purpose is to maintain a consistent temperature. As a result, defining the primary control responsibility of thermostats highlights their essential role in temperature management within these systems.