What type of component typically acts as an actuator in HVAC systems?

In HVAC systems, an actuator is a device responsible for controlling a mechanism or system. Motorized valves serve this function by regulating the flow of air, water, or steam within the system based on signals from a controller. When the temperature in a space deviates from the desired setpoint, the control system sends a signal to the motorized valve, prompting it to open or close accordingly. This ensures that the system can maintain optimal temperature and comfort levels.

Other components in the list, such as fans and compressors, may be involved in moving air or refrigerant but do not directly modify flow based on control signals. A temperature sensor also plays a crucial role by detecting temperature changes and relaying this information to the control system; however, it does not act to change the system's flow or operation directly. Therefore, the motorized valve is the component that precisely fulfills the actuator's role by physically adjusting flow rates in response to control signals.