If you’re a bit lost comparing the different types of fire dampers, you’re not alone. Unless you’re an expert in heating, ventilation, and air conditioning or fire safety, understanding the difference between a corridor fire smoke damper, fire damper, smoke damper, and corridor damper – and which one you should use and when – may not be easy. Thankfully, the team at Lloyd Industries is here to help.
What is a Corridor Damper?
A corridor damper, also known as a corridor fire smoke damper or combination fire and smoke damper, is a type of fire damper that is designed for installation in corridor ceilings. These dampers are used when air ducts intersect with horizontal spaces in fire-rated corridors.
Corridor dampers are manufactured to fit within ceilings and operate at a lower air velocity than traditional combination dampers. Like other dampers, corridor fire smoke dampers are available at different leakage levels.
What Is Corridor Fire Smoke Damper Leakage?
Leakage in fire dampers (both static fire dampers and dynamic fire dampers) refers to the accepted amount of air that can pass through a closed corridor fire smoke damper.
There are four ratings for leakage in corridor fire smoke dampers:
- Class IA
- Class I
- Class II
- Class III
Class IA is the least amount of air leakage, while Class III is the most. Any fire damper measured above a Class III leakage will not be certified by the Air Movement and Control Association International (AMCA).
Not only is leakage important for fire and life safety, but it’s also crucial for the efficiency of your HVAC unit. If your dampers are leaking, it can cause an increase in energy use, which is bad for your budget and the environment.
Why Are Fire Dampers Important?
Did you know that more than half of all fire-related deaths are from smoke inhalation, not from exposure to the actual fire? Keeping the amount of smoke that can spread throughout a building to a minimum can be the difference between life and death. Especially in buildings with many occupants, ensuring that people can escape safely in an emergency is vital and is a critical task given to corridor dampers.
Fires can spread instantly throughout a building’s HVAC system, and smoke can be a significant threat to people inside as well as first responders. Therefore, installing fire dampers is necessary, but don’t overlook corridor fire smoke dampers. Many corridor fire smoke dampers are connected to a central panel designed to close all the dampers automatically if smoke is detected.
Testing Corridor Fire Smoke Dampers
Although the saying goes, “where there’s smoke, there’s fire,” you can’t always depend on heat to activate smoke dampers. In order to close, smoke dampers use an actuator connected to an alarm.
The actuator can be internal or external and is operated in one of two ways:
Electrical actuators require power to work. Therefore, if the power is out or if the power is not correctly connected to the actuator, the corridor damper will fail.
Pneumatic actuators require air. If there is no air flowing to the actuator, insufficient air is flowing to the actuator, or an air line hasn’t been connected, the pneumatic actuator will fail, and the corridor fire smoke damper won’t close.
Installation Requirements for Corridor Fire Smoke Dampers
If a fire- and smoke-rated barrier is intersected by ductwork, then where the ductwork penetrates the barrier must have a damper that is at least equal in fire rating to the barrier. For example, if a wall is fire rated for 2 hours, then any corridor dampers must be rated for at least the same length of time.
There are multiple standards and codes that apply to installing and testing fire dampers, including:
- NFPA 1010, Life Safety Code
- NFPA 5000, Building Construction and Safety Code
- NFPA 90A, Standard for the Installation of Air Conditioning and Ventilating Systems
- NFPA 80, Standard for Fire Doors and Other Opening Protectives
- NFPA 105, Standard for Smoke Door Assemblies and Other Opening Protectives
The first step in installing a fire damper isn’t determining which codes apply – it’s following the manufacturer’s installation instructions. For new construction, there is a new regulation that requires inspection access to be given and that the access be approved. The access cannot impact the assembly’s rating, integrity, or continuity and must comply with any requirements stated in the mechanical code.
Corridor Fire Smoke Damper Testing
Underwriters Laboratories, or UL Solutions, is the standard for the evaluation and approval of dampers and many other devices. Each type of damper has its own requirements for testing it must pass to be approved, as well as a timeline of how frequently testing should occur. Both fire and smoke dampers have their own set of standards, and a corridor fire smoke damper must meet both to pass inspection.
The standard for damper inspections is:
- At installation
- One year after installation
- Every four years after its first inspection (except hospitals, which are inspected every six years)
Although it can seem like a waste of time to some, testing is the only way to ensure your fire dampers will work in an emergency. Dampers are useless unless you can ensure they are in proper working order when needed. If you’re responsible for the testing and maintenance of your building’s dampers, you’re a key player in the safety of everyone inside.
Common Corridor Damper Problems
There are several problems that inspectors see when examining corridor fire smoke dampers.
The top 10 that are most common are:
- Actuator isn’t getting power
- Actuator isn’t wired for power
- Inoperable actuator
- No air flowing to the actuator
- Too little air flowing to the actuator
- No air line connected to the actuator
- Broken or misaligned linkage
- Screw obstructing tracks
- Rusted damper
- Damper propped open
Where to Buy Corridor Dampers
Lloyd Industries has been manufacturing all types of dampers for more than 30 years. As experts in the HVAC industry, a partnership with Lloyd Industries means you can rest assured that there are people who care about your staff and building occupants just as much as you do. From answering your frequently asked questions about fire dampers to helping you learn how to get your HVAC ready for winter, the experts at Lloyd Industries are here to help.