Dynamic Fire Dampers 101

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Do you know the difference between an active fire damper and a static fire damper? If your office building or apartment is already on fire, this probably isn’t the best time to be thinking about the answer to that question (or reading this blog). However, knowledge is power. One of the best ways to protect yourself against harm from fire is to be aware of the technology that is keeping you safe. This blog, created by the experts at Lloyd Industries, will tell you what a fire damper is, how dynamic fire dampers work, and why you should know more about your heating, ventilation, and air conditioning system (HVAC) than just how to turn it off and on.

What is a Fire Damper? 

If you’re reading a blog titled Dynamic Fire Dampers 101, you probably aren’t an HVAC expert. To make sure you’re starting with a good base of knowledge, here’s a quick reminder about how fire dampers work. A fire damper is a device that is installed within an air duct, air transfer opening, or air distribution system that is designed to close when it detects that the temperature in the air duct has risen above a certain threshold. Fire dampers are installed by HVAC or fire professionals, at the intersection of fire-rated barriers to help prevent the spread of heat, smoke, and flames during a fire.

There are three styles of fire dampers: staticdynamic, and combination. The most significant difference between these three types focuses on three things:

  • How your HVAC unit operates when it detects a fire
  • The positioning of the fire damper within the air duct
  • How the damper closes when there is an emergency

HVAC Response

How the HVAC system responds to the threat of fire is the most significant difference between static and dynamic fire dampers. During an emergency, an HVAC system will respond in one of two ways: its fans will shut down, or they will keep running. If your HVAC keeps air flowing during an emergency, your HVAC unit will have a dynamic fire damper. However, in situations where the HVAC fans shut down when smoke is detected, or a fire alarm is triggered, experts will install a standard damper, also known as a static fire damper, in your air ducts.

Dynamic Fire Damper Styles

Dynamic fire dampers are designed for buildings where the HVAC system’s fans remain on during an emergency. However, either type of HVAC system can utilize a dynamic fire damper. Dynamic fire dampers are unique because they must possess a powerful enough design to close against moving air. Dynamic fire dampers must be UL 555 rated and carry an airflow velocity rating as well as a pressure differential rating. Experts recommend choosing dynamic fire dampers to operate against the conditions they will be exposed to once installed.

Dynamic Fire Damper Testing 

Each damper produced by Lloyd Industries is subjected to a variety of rigorous tests to ensure it’s suitable to be installed in your building. 

  • Fire Endurance Test: Each damper is required to pass a standard fire test for either one and a half or three hours. This test follows a specific time-temperature curve that exposes the damper to temperatures of more than 1600 degrees Fahrenheit. The hose stream test immediately follows the fire endurance test.
  • Hose Stream Test: The hose stream test is conducted to expose the damper to a severe shock and determine whether the dampers are structurally strong enough to protect against the most extreme fire situations. During this test, water flows at 30psi for one and a half hour dampers or 45 psi for three-hour dampers at a distance of 20 feet.
  • Dynamic Closure Test: This test evaluates the fire damper’s ability to close when exposed to airflow. 2000fpm is the minimum velocity at which a dynamic closure rating can be issued. According to the UL Standards, “Extended ratings can be achieved in increments of 1000 fpm.” If a damper is attempting to achieve a specific classification, the damper is tested at 400 fpm above the desired rating. The damper undergoes three rounds of the test at room temperature air, and then a final time at a temperature that causes the damper to close.  
  • Salt Spray Exposure Test: This test examines a damper’s ability to close after being exposed to harsher elements than it would during its intended use. During this test, the damper is exposed to salt spray for approximately five days. At the conclusion, the damper must be able to close and latch, if a latch is included.  
  • Cycling Test: The cycling test determines a damper’s ability to open and close as intended multiple times. For a non-actuated damper, one that is operated by gravity or spring-force, the damper must be opened and closed 250 times. For actuated dampers, the damper must go through 20,000 cycles. 

Installing a Fire Damper

Dynamic fire dampers are a critical piece of your building’s ability to protect you from harm in the event of a fire. Although every product manufactured by Lloyd Industries comes with detailed installation instructions, we recommend only allowing trusted professionals to install your fire damper products. Consult with an expert knowledgeable in the building codes of your state to ensure that your home or office building remains safe in the event of an emergency. Lloyd Industries also supplies detailed installation instructions on its website.

Do Fire Dampers Require Maintenance?

Inspections are required by the National Fire Protection Association (NFPA) for fire dampers one year after installation, and then every four years indefinitely. During an inspection, an expert will ensure that the dampers in your building are in perfect working order to prevent a failure during an emergency. The NFPA’s building codes require fire dampers. Although many people may feel as though a building is safe, hindsight is 20/20. Ensuring your building is up to code and equipped with a fully operational fire protection system is essential for keeping your employees safe.

Reliable Fire Damper Products

Lloyd Industries has been a proud manufacturer of fire protection products for more than 35 years. Whether you’re shopping for a specific product or want to learn more about our rigorous testing systemLloyd Industries is here to protect what’s most important to you and your company.