Kitchen suppression systems are designed, tested, and approved to provide fire protection for commercial kitchen cooking appliances, hoods, and ducts. The suppression systems consist of an agent storage tank, manual release station, an automatic releasing mechanism, and supply piping that directs the agent to nozzles strategically positioned at heat sources in the kitchen.
NFPA 17 requires that every 12 years the agent-holding tank, whether it is a pressurized or non-pressurized system tank, must be pulled out of service to be tested.
For all systems, the agent storage tank must be pressure tested to ensure the integrity of the cylinder. There are many types and manufactures of kitchen commercial wet chemical systems, each one has different test pressures for the cylinder, which are set by the manufacturer. Once filled with water, and sometimes oil, the cylinder is capped off, then pressurized to the manufacture test pressure and held at that pressure for no less than 1 minute. These systems are often tested to almost two times the service pressure.
On a non-pressurized system, there is a cartridge that pushes the agent out of the cylinder. This cartridge is replaced every 12 years. In some instances, these systems can have a burst disc that would need to be replaced before the 12-year hydrostatic test is scheduled.
Pressurized systems have valve stems, O-rings, and pins that need to be replaced. This is called a rebuild kit.
Once all of the cylinders are tested, dried, and documented they get filled back up with the proper wet chemical agent and put back into service if there is not any issues with the test pressures. All systems, both pressurized and non-pressurized, get new agent during a 12-year hydrostatic test. For certain suppression systems, hoses will need to be replaced at the 12-year hydrostatic test.
The National Fire Protection Association is a global nonprofit organization devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards. NFPA is widely known for its codes and standards which establish criteria for building, processing, design, service, and installation of fire protection systems. Several NFPA codes are being updated for 2017, here we will discuss some of the changes to NFPA 96, which covers Ventilation Control and Fire Protection of Commercial Cooking Operations.
Carbon Dioxide Extinguishers Not Permitted
10.9.4 was added to state carbon dioxide extinguishers are not permitted for use in Commercial Cooking Kitchens. Class K extinguishers are the recommended extinguisher for kitchen use.
Class K Extinguisher Placard
For each Class K Extinguisher in your kitchen, you need a placard conspicuously placed with each that states the extinguishing system be activated prior to using the extinguisher.
10.5 states that all systems are required to have both automatic and manual methods of actuation, and at least be located in a means of egress or placement acceptable to AHJ, and clearly identify the hazard protected. Sprinkler systems don’t require manual actuation.
Training for Extinguishers and System Manual Actuation
It is now required for managers to provide and document instruction on extinguishers and manual actuation for new employees at hiring, and to all employees annually. Records for training must be maintained and made available to the AHJ. In addition, instructions for use must be posted conspicuously.
Emptying of Grease Cans
11.6.16 was added to require that grease cans be inspected or emptied once every week.
Contact your Life Safety Partner for help updating your kitchen suppression system to comply with all 2017 code updates. This information is based on first and second draft revisions to the NFPA code for 2017. A1 strives to ensure the information we provide in our blogs is accurate, the information we provide is based on research and our understanding of State Fire Codes and NFPA regulations. You should always review the complete NFPA standards and local codes for where you are, as local and state requirements may differ.
Clean Agent Systems are the best fire protection system for your server rooms. For this suppression system to work properly, your server room construction needs to be specifically designed to limit leaks and hold the gaseous agent.
In reports from the NFPA, when automatic extinguishing equipment was reported present, sprinklers were reported in 72% of the fires. Wet-pipe sprinklers were reported for 90% of the fires with sprinklers present, compared to 7% for dry-pipe sprinklers and 3% for other sprinklers.
When wet-pipe sprinklers were present, 56% of fires were reported as too small to activate operational sprinklers. Clean agent systems can activate faster than traditional wet-pipe sprinklers and, since they do not use water, will not damage your electrical equipment when used. Debris, smoke, and water clean-up wreaks havoc on electronic gear. It also prevents your business from getting back to business as usual.
Server Room Construction for a Clean Agent Suppression System
Server rooms are generally constructed with the perimeter walls extending from the true ceiling (as opposed to drop ceilings and the like) to the lowest structural unit, either the floor itself or the concrete slab underneath the floor. This creates a fire rated barrier for the room and reduces the leaks a room will have in an Integrity Fan Test.
Server rooms should be prepared for a clean agent suppression system by inspecting the walls and slab for leakage points, sealing them with fire retardant materials, and fitting the doors with pressure seals around the jams and thresholds.
When constructing a server room, your contractors should ensure the following points are followed to allow for a clean agent suppression system.
Doors & Windows
- All doors must have a threshold and sweep installed
- Egress doors should swing out of the protected space
- Doors may require weather stripping around the jam to ensure an air tight seal
- Latching mechanisms are necessary and door closures are required
- If doors to the server room must remain open, an electromagnet door holder will be required which can be released prior to agent discharge
- All types of windows, pass through, or openings must be fire caulked and sealed
- Porous block walls must be sealed from slab-to-slab to prevent gas from leaking out of the block; two or three coats of paint are typically required
- Server rooms should be enclosed with wall partitions that extend slab-to-slab; in areas where this is not possible, all ceiling tiles should be clipped and openings caulked
- All walls should be caulked around the inside perimeter of the room where the walls rest on the floor slab and the walls intersect with the ceiling slab above
- Upgraded, noncombustible ceiling tiles are recommended
- Drywall should be caulked at the joints of the walls and floor, and at the roof or floor above
- Any penetration to the walls, including conduit, cable trays, outlets, switches and wire troughs, must be fire caulked and sealed
- If a raised floor continues out of the protected space, bulkheads must be installed under the floor directly under the partitions; these bulkheads must be caulked top and bottom
- All floor drains should have traps which are designed to have water in them at all times
- To ensure the protected area is air tight, dampers may be required in the ductwork at the perimeter walls of each protected space
- Dampers must be spring loaded or motor operated to provide 100% air shut off
- A 5% minimum leakage requirement must be met so the dampers must be UL #5555
- With clean agent fire suppression, the HVAC will be shut down prior to discharge, self-contained HVAC units may continue to run (if included in design calculations)
- HVAC shut down control relays should be installed to within 3 feet of each unit
- All exhaust fans should be dampered; fire alarm system control relays are used to shut down any fans
- All fresh air intakes should be dampered and closed using fire alarm system control relays
Power and Interface Wiring
- 120 VAC dedicated 15 AMP circuit to the suppression control panel is required
- Power to all dampers – control relays within 3 feet of damper
- Fire alarm monitoring – contacts for alarm, supervisory and trouble conditions are available within the fire control panel; connection is handled by your fire system contractor
- Purge system control wiring to HVAC units and exhaust fans are interfaced with fire alarm system control panel; connection is handled by your fire system contractor
Pressure Relief Vents
While ensuring that your server room is sufficiently sealed to contain the suppression agent for at least 10 minutes, you also have to take into consideration the maximum amount of pressure the room’s construction can withstand. The suppression agent is released with force, in a sealed room, if not calculated properly the pressure could be higher than the room can withstand. NFPA 2001, Section 5.3.7 states, “if the developed pressures present a threat to the structural strength of the enclosure, venting shall be provided to prevent excessive pressures.” Your suppression system designer should calculate Peak Pressure equations for your server room to determine if you need Pressure Relief Vents installed.
In addition to calculating if a pressure relief vent is necessary, and what size it should be, your designer should also calculate the leakage rate for the vent to ensure it will open and close at the correct pressure and will vent the proper amount of pressure to outdoors.
If Pressure Relief Vents need to be installed, here are some guidelines for optimizing performance:
- Install vents as high as possible so that the lighter air, not the denser agent, is vented
- Vents should open at pressures no lower than .007 PSI (50 Pa) so they don’t open unintentionally under normal HVAC pressures and no higher than .02 PSI (100 Pa) so the pressure is vented early enough to prevent it from becoming excessive
- Specify the correct direction for venting with the Pressure Relief Vent. Inert agent discharges always create positive pressures and must have venting out of the enclosure, but halocarbons may create positive and/or negative pressures creating a need to be vented in either direction or both, depending on the agent and the humidity
- All Pressure Relief Vents should be inspected annually to confirm they will open according to their specifications and to verify that the vent path to outdoors has not been accidently restricted
What type of fire extinguisher should I have to supplement the suppression system in my server room?
In 2006 to 2010, there were an estimated 209 reported U.S. structure fires per year that started in electronic equipment rooms. The annual, average estimated losses from fires in 2006 to 2010 include five civilian injuries, and $11.9 million in direct property damage.
While your building and server room should have fire protection in the form of sprinklers and a Clean Agent Suppression System, it is important to have a fire extinguisher near your server room to use for small fires before your Clean Agent Suppression System activates.
CO2 fire extinguishers have traditionally been used in small spaces. However, as CO2 fire extinguishers work by displacing oxygen in the space with carbon monoxide they pose a risk of asphyxiation to the user, especially in a small space such as a server room. Also, these extinguishers can create condensation which can lead to corrosion and damage to your equipment.
A better option is an extinguisher with a clean agent chemical in it, such as a Halotron Extinguisher, as this is not harmful to the user or the equipment. Clean Agent fire suppression utilizes inert gases and chemical agents to extinguish a fire. The clean agent is waterless and does not cause condensation so it is completely safe to use on electronic equipment.