In large commercial and industrial buildings, Fire alarms play an important role to ensure the fire compartmentation is maintained in the event of fire.
In these types of buildings, airflow for heating and ventilation is essential. However, to create such airflow, will require the air traveling through fire barriers. In the event of fire, the same paths could be used to spread fire and smoke throughout the building.
The solution to provide the required airflow for heating and ventilation during the normal operation of the building, and to enforce the compartmentation in the event of fire, is to install smoke dampers within each ductwork passing through the fire barrier. The smoke dampers are connected to the fire alarm panel usually via a smoke damper panel.
Smoke Vent System Installation
Fire Systems Ltd, design, installed and commission smoke vent systems as shown on the video.
In this video, Fire Systems Ltd, working for NG Bailey Rail, supplied and installed two twelve way Kentec smoke damper panels connected to eighteen “Actionair” smoke fire dampers.
The dampers have micro switches fitted to the ‘open’ and ‘closed’ positions. The outputs from these switches are connected to the damper panel.
All the fire alarm and smoke damper wiring was carried out in “FP Plus,” which is a fire rated enhance cable. The cables were given further protection as they were installed within galvanized trunking and tube.
The close-up view shows the “Action Air” damper in the closed position; this is shown by the black lever in the top position. The damper opens up when a 24v DC voltage is applied. On removing this voltage either by a fire alarm activation or a power cut the damper will close within the allocated 140 second window and stop any potential smoke or fire from transferring from one fire compartment to another and limit the spread of fire.
To ensure the fire dampers are given as much time as possible to close, detectors are installed within the ceiling void and at the room ceiling level. Another important point to consider is the sealing of any holes going through the fire barriers, as holes no matter the size can allow the smoke and fire to jump between zones.
Testing of Smoke Vent Systems
During the test as shown here, in status normal with the dampers in the open position, the LED’s within the damper panel will be green. On activation of the fire panel, simulated by our engineer activating a manual call point, the dampers have a window of 140 seconds to change from the open to the closed position. This is indicated by the LED’s changing to red. However, if any damper has not changed from the open to the closed position within the allocated time the damper panel will send a fault signal to the fire alarm panel.
These particular dampers are held open by a constant 24v dc supply coming from the fire damper control panel. If the dampers lose the 24v supply, either by the damper panel receiving a fire alarm activation from the fire alarm panel, or by a power failure, the dampers will lose its power and close. The arrangement is what we called ‘fail safe’. Once power is restored to the dampers, they will reopen.
For more information of smoke vent systems why not contact our office on 020 8541 5646 or visit our website on www.firesystems.co.uk and complete our contact form. We also provide fire alarm servicing for all types of fire alarm equipment.