Fire dampers are an essential element of any fire containment system. They are installed in the heating, ventilation, or air conditioning (HVAC) systems, when ducts are required to breach an otherwise fireproof barrier.
Fire dampers are generally triggered by heat – when the temperature in the duct reaches a certain level, a fusible link melts and the damper closes. They can also be closed via an electronic signal triggered by the fire alarm system. Once the damper has closed, the barrier is sealed and the fire is contained.
Of course, in order for fire dampers to work as intended, they must have been properly installed, correctly maintained, and not have been subject to misuse.
Let’s take a look at some of the reasons why a fire damper might fail.
Incorrect installation
This could be for several reasons, including:
- the damper is the wrong size – even if it operates correctly, if it doesn’t fill the duct space, it won’t contain the fire.
- the damper has been installed upside down – if that’s the case, then gravity will work against it and it won’t close.
- the damper is facing the wrong way for the airflow direction – if the HVAC system fan will continue to operate during a fire, then positioning the damper correctly in relation to the airflow means that the air pressure will help the damper to close and to stay closed; put it in the opposite way round and the opposite is true.
- the wrong type of damper has been installed – if you have a smoke damper instead of a fire damper, then it doesn’t matter whether it works, it won’t contain flame.
Lack of proper maintenance
There are various component parts of a fire damper that can be subject to failure.
When a fire damper is triggered, the blades are closed by springs, to seal off the opening. If the springs have corroded or jammed, or the blades have collapsed or been damaged, then the system will fail.
It’s also possible for the fusible link or the electronic trigger to fail.
An element of maintenance is cleaning – a build up of dirt can also prevent a fire damper from working correctly. Dampers need to be kept clean – especially important if building work has been carried out, causing additional dust and debris.
Damper has been subject to misuse
Never underestimate human idiocy! People have been known to run cables through dampers, so preventing them from closing fully, and also, for reasons best known to themselves, to chock them open.
What happens when a fire damper fails?
If a damper doesn’t operate properly, it might as well not be there. It means that your fire containment system is compromised and barriers that are intended to be fire resistant no longer are.
When flame and smoke can pass through a barrier, it spreads through a building more quickly. This can threaten people’s safety – and lives – as the time available to evacuate the building can be reduced. It can result in more damage being done to both the building and its contents. It can also mean that the fire service has a more difficult job when it comes to putting out the blaze.
How can I be sure mine are okay?
The only way to be confident that your fire dampers are working properly is to get them tested. After all, if there is something amiss, it’s better that a fire damper should fail during a test than during an emergency. With the enactment of the Regulatory Reform (Fire Safety) Order 2005, it is now the employer’s responsibility to maintain their fire safety systems. Compliance with this and BS9999 requires that fire damper testing is carried out annually as a minimum.
Prevention is always better than cure, so contact us today for a quote for fire damper testing.
