What are Fusible Link Fire Dampers?

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fusible link fire damper

When you enter a building, you rarely consider the various fire safety protocols that, including fusible link fire dampers, have been put into place to guarantee your safety until you leave again. Fire dampers, including fusible link fire dampers, are one of the many fire protection products woven into your HVAC (heating, ventilation, and air conditioning) system to protect you in the event of a fire.

What is a Fire Damper?

A passive fire protection product professionally used in HVAC ducts to slow the spread of fire inside the ductwork, a fire damper is one of the primary means of slowing a fire at its origin. When a fire breaks out, the heat will trigger the fusible link to close the blades of the fire damper, thereby impeding and slowing the spread, buying fire control and rescue workers valuable time. Fire dampers can be found in commercial and residential properties.

What is a Fusible Link Fire Damper?

A fusible link fire damper is a style of fire damper that is closed via a fusible link, as opposed to an actuator. There are automated systems or smoke alarms that can control some fire dampers, but the fire itself triggers a fusible link fire damper. The fusible link is activated by high temperatures and will remain open until it is exposed to high heat, such as it might be if a fire breaks out.

Fusible links are UL-approved, heat-detecting mechanisms that are soldered together and used to hold the blades of a fire damper open until a set temperature is reached. Generally, they are set to melt, thereby releasing the blades and closing the damper at 165 degrees Fahrenheit. However, when the fire dampers are placed in higher heat environments such as kitchens or laundromats, the temperature will need to be set higher, such as to 212 degrees Fahrenheit, for the fusible link to melt.

How Do You Reset a Fusible Link Fire Damper?

Unlike smoke dampers or other types of HVAC dampers, a fusible link fire damper is only able to be reset when an HVAC-qualified technician installs a new fusible link. These fire dampers are one-and-done pieces of equipment, so it’s of vital importance that a qualified, certified contractor installs your fusible link fire damper to make sure that it is in good working order and will protect you and everyone in your building if and when the need arises.

How Many Types of Fusible Link Fire Dampers Are There?

There are two types of fusible link fire dampers, and each one has a specific purpose, depending on your HVAC system and your building’s particular needs.

The types of fusible link fire dampers are:

  • Dynamic
  • Static

How do Dynamic Fusible Link Fire Dampers Work?

Dynamic fusible link fire dampers are used in vertical barrier HVAC systems. These are needed in systems where the fan will continue to run during a fire event. Spring-loaded, dynamic fusible link fire dampers have the ability to close even in the presence of moving air.

What are Static Fusible Link Fire Dampers?

Static fusible link fire dampers are utilized in barriers where the HVAC system’s fan will be shut off when a fire occurs. They are placed horizontally and have a curtain-like design rather than the blade design of dynamic fire dampers.

What Are Smoke Dampers?

Smoke dampers are another HVAC fire protection product. These are utilized to reduce the spread of smoke and other gases throughout a building’s HVAC system during a smoke or fire event. When activated, they will shut, thereby preventing smoke from moving any further within the HVAC system by virtue of a smoke barrier. Smoke dampers can be activated by several different methods, including:

  • Smoke
  • Fire
  • Smoke damper control system
  • Fire system
  • Smoke detector

Additionally, a smoke damper can assist your HVAC system in two ways. First, they can block smoke from traveling deeper within your HVAC ducts, and they can also be used to remove smoke and dangerous gases from your building by blowing them out of your HVAC system.

Unlike fusible link fire dampers, which are managed by the fusible link, smoke dampers are controlled by an actuator, which is turned on by a system activation. Once this occurs, the smoke dampers can open or close, depending on their type and what action is necessary.

How Do You Care For Fusible Link Fire Dampers?

Making sure that you have fusible link fire dampers as part of your overall HVAC fire protection plan is only the first step. Next, you need to make sure that you maintain your fire dampers according to regulations.

It’s generally recommended that fire dampers need to be inspected one year after installation and then every four years after that initial inspection. One exception to this is hospitals, which will need to be inspected six years after the first annual inspection. Make sure to keep records of your maintenance so that you are able to refer to them whenever needed. 

When it comes to damper maintenance, you should be able to document these key points:

  • The date maintenance was performed
  • The name of the technician performing the maintenance
  • The company that the technician works for
  • All aspects of the inspection, such as which products were inspected and their location
  • Any findings or issues that must be addressed
  • Any paperwork documenting the inspection and maintenance

Make sure to store these documents in a secure location and have copies in case of emergency. If your industry requires additional testing, you should schedule these far in advance so that you avoid missing deadlines and give yourself time to ask any questions you may have.

Fusible link fire dampers play a critical role in your building’s safe fire protection plan. It is critical to make sure you have the right pieces for your HVAC plan, and Lloyd Industries is here to help you get them into place. Don’t hesitate to contact us for all of your HVAC needs. Looking for a contractor or technician? Check our vetted list of professionals in your area!

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