Fire Suppression Enclosure Integrity

Posted October 30, 2020 by Koorsen Fire & Security

Server Room Integrity

Does your facility have a room that is protected by a clean agent fire suppression system? A server room, archive, laboratory, or technical room may have one of these unique systems to help protect your business' valuable assets in the event of a fire.

But did you know that if that room is not sealed correctly, the clean agent system, and the investment it represents, could be all be for naught?

Read on to learn about fire suppression enclosure integrity and why your business' assets depend on it.

What is Fire Suppression Enclosure Integrity?

Fire suppression enclosure integrity – also known as room integrity – refers to the integrity of a room protected by a clean agent fire suppression system.

Room integrity describes how well or poorly the protected room is sealed, impacting how the design concentration is maintained inside the enclosure. Things like loose or missing ceiling tiles, large conduit openings, poorly sealed windows or doors, and holes can negatively impact a room's integrity.

Why is Room Integrity Important?

The reason room integrity matters is because of the way clean agents work.

A clean agent discharges in gas form, filling the room and suppress the fire. The gas must maintain a specific concentration within the space to be effective.

Industry-standard states that the room should be able to maintain the necessary concentration of clean agent for a minimum of 10 minutes to prevent the fire from reigniting at its ignition point, which is especially important in the cases of an electrically charged fire.

If a room has significant leak points, such as missing ceiling tiles or leaky windows, the gas will escape through these holes, decreasing its concentration levels to such a point that it becomes ineffective. The fire could reignite, essentially nullifying the suppression system.

Verifying room integrity for all rooms using a clean agent fire suppression system is vital, therefore, to ensure that your suppression system will be effective in the event of a fire.

How is Room Integrity Verified?

Verifying a room's integrity for a clean agent suppression system involves a number of steps.

The first step is a simple visual inspection to identify apparent leaks, like missing ceiling tiles, holes in walls, gaps between the wall and the floor, conduits open, what are the conditions under the subfloor (if present) or bottom of the walls, are there proper door seals and sweeps and if a double door, are there proper seals.

The second step, which is required by the NFPA, is a more involved test that helps identify less visible but still dangerous leak points where the gas could escape. It is known as the room integrity fan test or door fan test.

During a door fan test, Koorsen or your fire protection vendor will seal the door and use a special fan that is hooked up to a program to record readings. This may also require the shutting down of any HVAC and/or dampers.

Prior to running the fan, the technician will use equipment to identify whether the pressure in the room is positive (pressure inside the room is greater than outside of the room – air flows out of the room) or negative (pressure inside the room is less than the air outside of the room – air flows into the room).

Once that is determined, the technician will run the fan to pressurize, then depressurize the room, all while the fan is hooked up to a program that will capture measurements and the pressure within the room.

Once the room has been both pressurized and depressurized and all of the readings have been collected, the data collected by the program will be able to provide the following information, based on the room's cubic area and the suppression agent you use:

  • Allowable leakage area, in square inches, for a room that size with the selected agent
  • Measured leakage area of your room
  • Worst case retention time – how long the clean agent will stay within the measured room

There are two methods to the room integrity test, descending interface and continual mixing. In descending interface, the ceiling height and the highest protected equipment are measured, and the information is placed into the program. Descending interface is basically measuring the time it takes the agent design concentration to maintained at the highest protected height. So, what is the time from ceiling to the equipment it takes for the agent to be at that height after the initial discharge, and the enclosure has been flooded with the agent?

Continual mixing is when the self-contained air for the enclosure is still on. As the agent discharges and fills the room, the air movement will continually mix and keep the agent concentration within the room. Both methods are acceptable, and one is not necessarily better, but depending on the enclosure's layout, one may be a better option.

If an enclosure has a drop ceiling, then, to ensure that readings are as accurate and helpful as possible, after running the initial fan door test, your fire protection provider should run a BCLA – below ceiling leakage area – test. Some providers may only take the total equivalent leakage area (ELA) and divide it in half, assuming that 50% of the leaks are above the ceiling and the other 50% of the leaks are in the enclosure. However, this is not the most accurate measurement.

Performing a proper BCLA test requires two fans - the original fan used for the enclosure and the another fan placed on top of the first fan with a flex duct that is ran up into the ceiling. Once both fans are turned on, adjustments are made until both the ceiling and the room are neutral. This eliminates the ceiling space from the equation and allows you to determine what leaks there are beneath the ceiling and how significant they may be.

Getting accurate BCLA readings matters because leaks from low points in the room could negatively impact the suppression agent's concentration faster than higher, above ceiling leaks because the gasses used as suppressing agents are heavier than air – the agent will naturally sink toward the floor. However, it will fill the whole room effectively.

While a low leak could quickly dissipate the gas from the room, a high leak may not ever end up impacting the agent's concentration levels at all. Think of these enclosures as a gallon water jug. By removing the cap and turning over, the water kind of gurgles out until air can get behind the water, then the water will quickly run out of the jug. But if you take the same one gallon water jug, remove the cap, then place a hole on the bottom, the water will flow out fairly quickly. With these enclosures, the lower leaks are or can be the most critical and the effect can be greater if there are leaks above the ceiling or higher in the room.

A quality fire protection company, like Koorsen, will be able to perform the fan door test with thoroughness and accuracy, attaining the correct ELA and BCLA readings to ensure the integrity of your fire suppression enclosure.

What Jeopardizes Fire Suppression Enclosure Integrity?

Ideally, rooms where clean agents will be used to protect sensitive, valuable contents, such as server rooms, archives, etc., should be constructed as such – meaning they should be built specifically as fire suppression enclosures.

This ensures minimal leakage because walls for such rooms will be sealed at the floor and run up through the ceiling to the roof deck. They will also be built to cut off or damper airflow from the HVAC system should the suppression system trigger. Doors and windows will have special jams and sweeps to seal them off and prevent leakage.

Where enclosure integrity frequently becomes jeopardized is when a room that was not designed to be a fire suppression enclosure is turned into a server room or the like. The facility manager may pay to have a clean agent suppression system installed for the room. But, if the room was not designed for room integrity, these efforts may be a waste of money and effort since the clean agent will be ineffective in an insufficiently sealed space.

However, even in rooms designed explicitly as fire suppression enclosures, there are things people may do that could jeopardize the efficacy of the suppression system.

Following are some critical dos and don'ts to follow to protect your room integrity:

Don'ts:

  • Don't move a ceiling tile and neglect to put it back.
  • Don't put a hole in the wall to run wires or install outlets and neglect to seal it properly.
  • Don't leave fire suppression enclosure doors open if they do not have door releases installed that automatically shut the doors in the event the system triggers.

Dos:

  • Do have an enclosure integrity test if one was never performed or if there have been any significant changes to your protected room (server rooms in particular).
  • Do consult your fire protection vendor if you have changed the airflow / HVAC system to your server rooms as it may have impacted your suppression system's ability to perform.
  • Do insist on having a Room Integrity Fan Test done on any room before you install a clean agent suppression system in it.

Will Your Fire Suppression System Work?

If your fire suppression enclosure has not been properly constructed or sealed, it may not matter if your clean agent system discharges in the event of a fire or not. Leaks may cause the agent to dissipate and be unable to suppress the fire long enough to keep it from reigniting. Valuable assets could be lost, and your business fatally harmed by the loss.

If you're not sure whether your room's integrity is sufficient, don't wait. Call Koorsen today to schedule an appointment. One of their expert technicians will take a look and determine whether your room and its suppression system are ready.

If you plan to install a clean agent suppression system, make sure the vendor you are using can help you create a properly sealed room so that your investment is not wasted. At Koorsen, they are ready to help you design a properly sealed room so that your assets are protected.

Give Koorsen a call today to get started.

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Topics: Fire Protection, Fire Suppression

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Disclaimer: The information in this article is for informational purposes only. It is believed to be reliable, but Koorsen Fire & Security assumes no responsibility or liability for any errors or omissions in the content of this article. It does not constitute professional advice. The user of this article or the product(s) is responsible for verifying the information's accuracy from all available sources, including the product manufacturer. The authority having jurisdiction should be contacted for code interpretations.