Decommissioning Fire Dampers

by Paul Greenwalt, EIT and Mike Lehner, P.E.

This article is part of Wood Harbinger’s newsletter series.

We have all heard of commissioning, but what is decommissioning? Oddly enough, it does not require the services of a Certified Commissioning Professional (CCP) or other similar licensed commissioning provider. In the case we’ll discuss here, it also does not include dismantling nuclear weapons (although it may seem as daunting a task). We are talking about the trend to label and disable existing fire dampers, smoke dampers, and combination smoke‑fire dampers.

The Big Deal with Dampers

Life safety plans are a combination of the right equipment and sensible policies and procedures that are kept current and implemented properly.  Life safety plans typically show required fire ratings for all walls and egress pathways, that is, the safe passage of people out of the area, to verify code compliance. Where ducts cross fire and/or smoke rated barriers (walls), they need to be rated as well.  Three types of rated dampers maintain the fire rating of various walls in a building to allow for control of the smoke and fire to provide egress..

Smoke dampers are used to prevent the spread of smoke from zone to zone between which is a defined smoke barrier. Fire dampers are applied to fire-rated walls. They use a sensor to detect smoke. Upon smoke detection, these dampers close (usually spring-actuated) to maintain the fire rating of that wall. Combination smoke‑fire dampers are used in walls that have greater than 2-hour rating or that are smoke and fire control barriers. Smoke‑fire dampers use dual sensors to detect smoke and fire. They are typically motor-actuated, must be tied in to the fire alarm system, and require regular testing.

If these devices are so important for life safety, then why would we consider decommissioning any of them? The truth is, they’re only valuable if they’re in the right places. They can even be a risk if they’re not used in the correct location.

In some cases, designs have been over‑using fire, smoke, and combination smoke‑fire dampers. If you need to know where a specific type of damper is required, then you turn to the International Building Code (IBC). The IBC is not the most exciting piece of literature to read through, and it is not always clear when some type of damper might be required. Duct layout can be difficult to identify, requiring a fire or smoke damper based on where the duct originates, what it serves, and its purpose.

Is this why designers over specify? If they’re unsure of which is needed where, they spec the combined one any place there’s a chance it might be required?

Safety + Simplicity

At a local hospital, I was called upon to address an issue with a recent inspection. The agency performing the inspection noticed that there were some deficiencies in the Life-Safety Plan and the HVAC system serving the areas bounded by various rated walls. My job was to determine which walls were changing and if the new boundaries were properly sealed with appropriate devices. Additionally, if there were any dampers that could be disabled in place without disturbing the wall rating, then I was to mark it for decommissioning.

The primary goal was to conform with the code and address the notice issued by the inspection agency. The tertiary goal was to reduce the maintenance cost incurred by having many active dampers spread throughout the facility and often in places that had restricted access and sensitivity to intrusion.  For every damper that’s not required, that can pose additional maintenance costs to the owner that aren’t necessary.

Once you are familiar with the IBC rules, it is easier to design better systems that use each specific damper in the right place. Trying to determine what can be decommissioned and what needs to remain operational is a much more challenging task.

There’s a process to determine which dampers need to stay in use and what can be disabled. First, find out exactly where all existing dampers are, what type of damper they are, and what spaces they serve. Second, compare the life safety plan with the HVAC plan and the collection of dampers. Consult the latest building code to verify compliance. Be sure to have someone QC your work! It is very easy to get yourself confused as the systems are complicated, intricate, and somewhat imprecise.

Despite the challenges of determining which dampers can be decommissioned, owners are finding it beneficial to pay to decommission the dampers to save the headache of having to schedule maintenance and testing especially in sensitive areas. Any device that detects a threat to life safety must be tested periodically, according to NFPA 72. Smoke, fire, and combination smoke‑fire dampers fall into this category and thus require semi-annual testing according to the schedule provided in NFPA 72. This testing involves disabling the fusible link, sensor, or detector and operating the dampers. Physical access to the damper and related components often times is a problem and inconvenient to the surrounding space occupants.

Prepared for the Present and the Future

Another challenge we face is instructing the contractor how to properly decommission these dampers. In fact, you might be asking yourself, “Why not just remove them if they are not required to be there?” The answer is that there is a concern that current Life-Safety Plans may need to be changed to remain compliant.  There is also no guarantee that these dampers are not going to be required in the future, so owners are not removing them, just decommissioning them for the time being.  In this way, owners get the benefit of reduced maintenance headaches, while still better safe than sorry!

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2 Comments

  1. Steve Woolery
    Posted October 23, 2018 at 4:31 pm | Permalink

    How is a fire damper or fire-smoke damper decommissioned, such that it might be used at a later date? Is wire used to tie a smoke or fire/smoke damper shaft in the open position? Or to tie a curtain-type fire damper’s curtain in its folded state?

  2. Paul Greenwalt
    Posted October 30, 2018 at 11:12 am | Permalink

    Steve, thank you for reading our article! Your question is a good one. On past projects we have instructed the contractor to wire-tie the actuator shaft of blade-type dampers open in a non-permanent fashion. For curtain-type dampers, we have asked the contractor to install rods on either side of the curtain to hold the damper in the open position. However, you should always coordinate these methods with the fire marshal to make sure that they allow this and are comfortable with the modification.

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