Thermal actuators are devices that convert thermal energy into mechanical motion. They typically use materials that expand or contract when heated or cooled, allowing them to move components in systems like valves or dampers. This type of actuator is commonly found in heating, ventilation, and air conditioning (HVAC) systems, where precise control of airflow and temperature is essential. These actuators can be powered by various heat sources, including electrical resistance or hot fluids. They are valued for their simplicity, reliability, and low maintenance needs. Thermal actuators are often used in applications where precise positioning is not critical but where automatic operation is beneficial.