Fire Prevention Training

Smoke Vents

Large retail store roof top showing both HVAC Units as well as several Plastic Domed Smoke Vents.


Smoke vents in the closed position.

To open the Heat Smoke Vents, firefighters must pull a release cable.

A warning tag is attached to the Release Cable Pull Handle stating: 

"WARNING! DO NOT PULL THIS RELEASE CABLE if you are not an authorized fire department employee. This equipment is an emergency fire safety device and should not be operated for any other purpose."

The lids will remain in the full open position until manually closed and hydraulic shock absorbers assure smooth operation, preventing damage to the unit. A manual cover release permits inside operation (outside operation optional) without disturbing the fusible link assembly and the latch automatically resets as the covers are closed manually. Once the cable has been pulled, both doors will remain opened until reset.

Caution labels warn firefighters that the smoke vent opens automatically once temperatures melt the fusible link.

The fusible link is located in line with the cable release system.

Tension is maintained on the fusible link with the use of a heavy duty spring.

View of the Smoke Heat Vent from the ground level.

To close the smoke heat vent, two people are needed to unlock the safety and compress the spring loaded vent doors.

The Spring Loaded Locking-Channel On Shock Absorber must be disengaged before closing the doors.

Both ends of the door have a locking mechanism that must be engaged using considerable force to put a load on the system.

Acceptance: Any required smoke control design that requires operation of mechanical equipment shall be functionally tested until proper operation of all required mechanical equipment and controls is demonstrated.

Click here to see the specifications sheet for the Bristolite Skylights Smoke Vents.

Website Created August 2002 for Fire Department Training Only

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