This Self-Powered Thermostatic Vent is used to regulate airflow into an electronics cabinet to maintain a stable temperature. Requires no batteries or external power source.
As the air temperature inside the enclosure rises to within the actuation temperature of the device the thermal material contained within the thermal actuator changes phase from a solid to a liquid increasing in volume. This causes the actuator piston to extend outward against the push rod lifting the vent lid off the mounting plate allowing the hot air to escape. As the enclosure cools to within the contraction temperature of the thermal material it reverses phase back into a solid contracting in volume retracting the actuator piston with the aid of the return spring closing the vent lid. Typical temperature span between open and close is 15°F.