Thermal releases

Thermal releases, often called thermal initiators or TAGs, are used to trigger a smoke and heat exhaust ventilator (SHEV) locally in the event of a fire. When the ambient temperature of the TAG exceeds a certain threshold, a glass vial bursts and the CO2 cylinder is pricked. This causes the gas to flow into the pneumatic cylinder and opens the smoke vent. The glass vials are available for different temperatures. The most common are 68°C and 93°C. Care must also be taken to ensure the correct diameter for the glass bulbs. The thermal activators differ in their use (installation in systems with open-close cylinders, "open only" systems, with/without venting...) and in the connection thread for the CO2 cartridge.

TAGs can also be triggered remotely. For example, with 24V, pneumatic or pyrotechnic elements (compressed gas generator, compressed gas release). There is also the possibility of a "triggered" feedback. Here, a spring-loaded contact senses the state of the glass bulb and closes a contact when a local SHEV release has occurred.