5 Things You Didn’t Know About Smoke Dampers

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Corridor Fire Smoke Damper

Smoke dampers, like fire dampers, are part of your overall HVAC (heating, venting, and air conditioning) fire defense system. They protect your building in case of a fire or smoke event. While they serve a potential life and building-saving purpose, we do not think about them except when they are pulled into service. Read on to learn five things you did not know about these fantastic inventions!

What are Smoke Dampers?

Smoke dampers are HVAC fire protection products that reduce the spread of smoke and other gases through a building’s HVAC system during a smoke or fire event. They will shut, preventing the continued movement of air and smoke through a duct or ventilation opening by virtue of a smoke barrier. Sheet metal contractors or HVAC experts will install smoke dampers into air conditioning and ventilation ductwork or physical smoke barriers such as walls and/or ceilings when installing your HVAC system. 

What Do Smoke Dampers Do?

A smoke damper does several critical things within the HVAC system. First, it is activated by either smoke, fire signal, smoke damper control system, fire system, or local smoke detector. When a signal is received, the smoke damper actuator, which holds the damper open, will close it.

When installed within a smoke barrier, the smoke damper will restrict smoke passing through the duct when activated during a smoke event.

These dampers also:

Assist in smoke extraction from the building 

Operate pressures within the building to prevent smoke spread

Aid in the effectiveness of a gas suppression system          

How Often Do Smoke Dampers Need to Be Inspected?

Like fire dampers, smoke dampers need to be inspected, maintained, and repaired, if necessary, to ensure that your fire protection is kept up to date. Once installed, they need to be inspected at the one-year mark. After that, they should be tested and inspected every four years unless they are in a hospital, in which case, the inspection, and testing should be done on a six-year schedule.

5 Things You Didn’t Know About Smoke Dampers

1. Two styles

2. Activation varies

3. Will open or close when activated

4. Has an actuator

5. Two types

1. They come in two shapes – Smoke dampers come in a rectangular shape or round shape. The type of smoke damper the specialist chooses will be dependent on your HVAC system needs. 

2. Activation styles can vary – Smoke dampers can be activated in several ways. First, they can be activated by a fire alarm system. However, they are generally initiated by smoke detectors or looped into a fire suppression system. Additionally, some are activated solely by the presence of smoke.

3. Depending on placement, smoke dampers will open or close – Smoke dampers, depending on where they are installed, will either close when activated or open. When smoke is detected, and the smoke damper is installed in a smoke barrier within the building, it will close. This way, it creates an effective smoke protection system.

If it is installed along an exterior wall and activated, it will do the reverse instead. By opening, it will usher smoke out of the building into the outside air, effectively helping to remove smoke and clear the building of dangerous fumes.

4. Smoke dampers have actuators –Spring-loaded actuators or electric actuators trigger smoke dampers. The spring-loaded actuator, also known as a pneumatic actuator, needs air to function correctly, whereas the electric actuator needs electricity to work.

5. There are two types of smoke dampers – Smoke dampers are made of two types, passive and active. The passive smoke dampers only need to close, effectively blocking the smoke and creating a smoke barrier. Generally, the fans will be disabled at the same time.

The second type is active. The active system depends on the ventilation system to create either a pressurized system or an exhaust air system. The pressurized system will provide supply air and exhaust air at specific locations within the building to allow different pressures across smoke barriers, allowing smoke to be kept in or out of an area.

The exhaust air system allows and maintains the smoke level in a space above escaping occupants. Mechanical means achieve this, and the dampers are controlled to open and close. 

Is There a Difference Between Smoke and Fire Dampers?

Both fire dampers and smoke dampers are meant to protect life and property by limiting the spread of smoke and fire in the event of a fire. So, what makes them different? Several critical differences separate the two.

Fire dampers operate by virtue of a fusible link. This holds the fire damper blades in the open position. When heat from a fire reaches a set temperature (generally 165 degrees Fahrenheit), the fusible link melts, and the fire damper blades close, effectively creating a fire barrier. When this happens, the fire is prevented from traveling past the fire damper and further in the ductwork.

As we have seen, smoke dampers are operated by an actuator, which is triggered by a system activation. Once this happens, the smoke dampers will open or close, depending on their type and the necessity of their action. 

Fire and smoke dampers are those specialty dampers that are utilized to restrict fire spread and smoke movement. Whereas the fire damper closes when it senses heat and the smoke damper closes in the presence of smoke, the combination fire and smoke damper will close when it is in the presence of either fire or smoke.

Smoke dampers, like fire dampers, may seem like minor marks on your HVAC system’s blueprint, but they can have massive returns if a smoke event ever occurs in your building. Having them installed, however, is only half the story. Making sure you keep up with repair and maintenance will keep your building safe and worry-free.

If you have more questions, please contact us at Lloyd Industries! For 35 years, we have been trusted leaders in the HVAC product industry, and you can count on our list of vetted professionals for your installation needs.

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