What Is a Fire Damper and How Does It Work

Fire Dampers

Fires in commercial properties and private homes are not something common. However, nobody is 100% protected against them. One forgotten iron is all it takes, given enough time, to turn into a blazing fire. If you are running an HVAC system or ducting vents, you may have one more way for the fire to spread. Unless you have properly installed and working fire dampers.

A couple of question may arise this instant. What is a fire damper? How does a fire damper work? Where to get them and how to install them? In the following paragraphs, we will give answers to those questions.

What is a Fire Damper

Fire dampers are ducting fittings. They are usually used whenever there is a fire-resistant wall in the property. Because of the ducting vent, there will be a place through which fire and smoke can escape from one room to another. Fire dampers are what stops the flames and smoke from passing through.

Those fittings are often made out of galvanized steel. There could be vertical or horizontal dampers, depending on the way it shuts the ducting close. Each is suitable for different applications.

Fire Damper Types:

  • Dynamic – installed in vertical barriers, these particular fire dampers have a spring-loaded mechanism. In case of fire, the mechanism is released and the doors of the damper shut close. The fan in the system will continue to run and build up pressure. This pressure will help keep the fire dampers’ doors closed.
  • Static – installed in horizontal barriers, these fire dampers have a curtain-like design. In case of fire, the curtain drops, preventing passage for heat, flames and smoke. These dampers are installed where ducting fans will no longer work if a fire is detected.
  • Fire/Smoke – those are the dampers designed to block both, fire and smoke. Usually, those are what you need. However, in some specific cases that may not be accurate. Sometimes you would want to let the smoke escape the room to alert others without unleashing the fire.

But how will the fire damper “know” that there is a fire in the room? Well, that leads us to our next topic.

How Does a Fire Damper Works

There are a few different options. You may want hard-wired solutions for some rooms or programmable solutions for others. Hardwired fire dampers would engage without a command being sent from a sensor, it will just work on its own. Programmable solutions, on the other hand, could be operated from a distance and could be wired in such a way that the process will be fully automated. In case of fire, sometimes power lines are being shut and fire dampers with mechanical engage are needed.

The fire dampers that operate without the need of circuits and sensor are relying on a fusible link. This link will meltdown from the heat (at around 72°C), generated by the fire and will engage the fire damper, closing its doors for good. There is one more option. As you may know, most metals expand when heated. Well, thanks to that fact, designs of fire damper made out of slotted metal plates are present on the market. The slots close while the metal expands from the heat, sealing the ducting while the heat doesn’t drop.

The fire dampers that have circuits can be engaged and disengaged via a control station somewhere or programmed to engage in different scenarios. For instance, you can wire your fire dampers to your smoke detectors. Whenever a smoke detector turns on, it will send a signal to the fire/smoke damper to close. As we have mentioned before, this needs to be implemented in systems where there is a backup power supply. Or in a system with its own power bank.

Considering the important safety features of those devices, they should regularly be checked and maintained. Fire damper maintenance for models with fusible links is a matter of checking if the link is still there and not covered in grime and dust. Fire dampers with circuits should be tested more often. Physical examination of the dampers should be regular, even if the tests are positive.

If you are in a process of building a ducting or HVAC system, make sure to include fire dampers in your plans. In case you are wondering which way should you go, why don’t you ask us at 01455 616444. The competent staff behind the telephone can help you choose your fire damper.