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.
According to the National Fire Protection Association (NFPA), more than half of the 8,160 structure fires involving commercial cooking equipment or ventilation components that occur annually begin in kitchens or cooking areas. Between 2004 and 2008, these cooking fires caused three deaths, 100 injuries, and $229 million in director property damage each year.
A kitchen hood is important fire protection at it eliminates air contaminants and toxic chemicals from the air, which are released when cooking. The filters in the kitchen hood capture grease and debris in these fumes and prevents them from entering your exhaust system.
Kitchen hood grease filters are an important fire prevention device. With grease or debris in your exhaust ducts, a fire could occur within the hood system. Duct fires can be intense, difficult to extinguish, and are susceptible to re-ignition.
No cook likes to clean the grease filters, however, regular cleaning of your grease filters is critical to maintaining proper function. Let your kitchen staff focus on their real job functions and remove this risk of worker compensation claims by collaborating with a knowledgeable partner to clean your filters. Having your Life Safety Partner perform this service will save you money while also keeping your employees safe, and your kitchen in compliance.
A filter exchange program can be a real benefit to any food service company or restaurant. At the intervals required for your kitchen, based on cooking methods, appliances, and volume of operation, your filters will be scheduled for automatic replacement.
Not only are the dirty filters removed and replaced with clean filters, but also the dirty filters are taken off-site to be cleaned. By not cleaning the grease filters at your restaurant you can reduce the amount of grease going down your drain by up to 70%, and the grease will be disposed of in an environmentally friendly manner. This offsite cleaning will save you money by reducing chemical costs, water usage, and the amount of grease in your traps.
Kitchen Hood systems are one of the most widely used fire protection systems given the fire source and fuel load. Kitchen Hood systems include the hood, exhaust, and ducting systems over your cooking appliances. This system vents airborne grease, combustion products, fumes, smoke, odors, heat, and steam.
These systems are customized for the kitchen layout as well as each appliance. Kitchen Hood systems require regular maintenance and inspections as grease build-up, damage to the hood, or moved appliances can cause the Hood system, along with any interconnected fire suppression system, not to function properly. You can read A1’s blog for more information on the kitchen hood suppression system.
The required schedule for cleaning a Hood system varies based on the type of cooking appliances, methods, and amount of use. According to NFPA 96, general guidelines for cleaning a Kitchen Hood system are as follows:
- Kitchens with solid fuel such as wood or charcoal must have the kitchen hood system cleaned every month.
- Kitchens with a high volume, 24 hour operations, charbroiling, or wok cooking must have the kitchen hood system cleaned every 3 months.
- Kitchens with moderate volume operations must have the kitchen hood system cleaned every 6 months.
- Kitchens with low volume operations, such as churches, day camps, seasonal business, or senior centers, must have their kitchen hood system cleaned once a year.
Because the Kitchen Hood system is cleaned in areas you will not be able to see on a daily basis, such as inside the ducts and vents, it is important that you are provided with before and after pictures of your system such as the ones shown here. You also want to be sure that all areas of your Kitchen Hood system are being cleaned – this includes fans, vertical duct, horizontal duct, plenum, inside and outside of the hood system and cleaning inside access panels.
Most of these areas are not ones that are not regularly visible. However, grease buildups occur throughout the system and it is critical that the full hood system is cleaned to bare metal in order to ensure proper function and continued safety.
Portable extinguisher locations are dependent on both the hazards and the occupancy types. A school will experience different hazards than a doctor’s office. Translating NFPA requirements can be tricky. Here’s the code down to the safest, most basic minimums.
An ABC extinguisher is the most commonly used extinguisher in facilities today. These extinguishers provide coverage for areas with normal combustibles, flammable liquids, and electrical fires. ABC’s are a fundamental necessity for light to ordinary hazard areas such as schools or offices. Typically, though there are small exceptions depending on extinguisher size, these extinguishers should cover a maximum of 50 ft from a hazard.
D Class portable extinguishers suppress combustible metal fires. These extinguishers must be a maximum for 75 ft from the hazard. D’s require more attention during the selection process as their size requirements are dependent on the types of combustible metals present, as well as manufacturer recommendations.
K hazards are those involving cooking oils, grease, or any other combustible cooking media. K’s must be located at a maximum of 30 ft from the hazard. I also recommend using a kitchen hood suppression system for large cooking appliances.
CO2 extinguishers are used in special hazard areas consisting of equipment or processes of exceptionally high value, unique or irreplaceable assets (museums, archives, art galleries, records storage), or production is of greater value than the equipment itself. CO2’s usually accompany laboratories, mechanical rooms, fuel or battery stations, and flammable liquid storage areas. These extinguishes work by removing the oxygen that fire requires and by cooling the material that’s ablaze. CO2’s are best used for BC rated fires and are usually ineffective when used with an A rated fire. CO2’s must be located at a maximum of 75 ft from the hazard.
Clean Agent Extinguishers
Clean agent extinguishers consist of halons, halotrons and FE-36’s that leave no residue and cause no damage. Like the CO2’s extinguishers protect high-value assets such as computer rooms, telecommunications facilities, process control rooms, museums, archives, marine, hospitals, banks, laboratories, and airplanes. Clean agent extinguishers are ABC rated and must be located at a maximum of 75 ft from the hazard. As an additional note: Halon extinguishers have been discontinued due to their negative environmental effects. FE-36 extinguishers are the recommended replacement for halons.
Extinguishers require a monthly visual inspection to pinpoint any physical damage or tampering with the device. All extinguishers need an annual inspection performed by a certified professional.
Cooking is the leading cause of death and destruction from fires in the U.S. Cooking fires account for $16.4 million in property damage annually. Additionally, cooking was the leading cause of fire in all healthcare facilities (nursing home, hospital, mental health facility, clinic or doctors office) according to NFPA US Structure Fires in Health Care Properties Fact Sheet (download it here). Keeping up with your required kitchen hood system inspections is an important part of protecting lives and your facility.
Kitchen hood suppression systems are designed, tested, and approved to provide fire protection for commercial kitchen cooking appliances, hoods, and ducts.
Kitchen hood systems have an efficient, automatic detector response that acts fast to suppress flames. Kitchen hood systems eliminate the need for a constant supply of the suppressing agent and manual shut off of the appliance’s gas and electric, while blocking any danger of a violent reaction that may spread flame or spill cooking oil.
Facilities that should have kitchen hood systems:
- Gourmet Restaurants
- Sports Complexes
- Fast-Food Chains
- Retail Food Courts
- Convenience Stores
- Hotel Kitchens
- School Cafeterias
- Food Service Kitchens
Kitchen hood systems will extinguish fires caused by the following:
- Deep Fryers
- Upright Boilers
- Plenum Chambers
How Do Kitchen Hood Systems Work?
When a fire starts in a protected area, heat sensitive links activate the kitchen hood system. The system stops the cooking appliance’s gas and electric supply. An extinguishing agent releases through nozzles and onto the appliances, plenum and duct.
At the first sign of fire, remember to evacuate the building and call 911. Stand by with a K class extinguisher just in case the system fails to act or a re-flash occurs.
Types of Restaurant Fire Suppression Systems
Wet Chemical Systems
Wet chemical systems are the most commonly used kitchen hood system. The wet chemical agent suppresses fire by cooling and reacting chemically to produce a foam layer on the grease. The foam seals combustible vapors, stopping the flames from re-igniting.
Dry Chemical Systems
Dry chemical systems were used to extinguish flammable liquid fires involving live electrical equipment. Dry chemical interrupts the chemical reaction of fire by removing the oxygen from the source. When the multipurpose dry chemical is discharged, the agent leaves a residue on the burning material. The residue seals the material from the oxygen to suffocate the fire. Unfortunately, because deep fryers are much more insulated than in the past, dry chemical systems are not capable of extinguishing kitchen fires. UL 300 Systems are recommended as a good replacement for dry chemical kitchen hood systems.
UL 300 Wet System
UL 300 systems use wet chemicals to smother the fire (like dry chems) and to prevent re-ignition by cooling the flammable liquids (unlike dry chems). The UL 300 standard represents the heightened suppression innovation to accommodate new, hotter cooking methods and is currently the most effective way to suppress a kitchen hood fire. If you are due to change your kitchen hood system soon, most states will require you to update to a UL 300 system.
Living and Caring for Your Restaurant Fire Suppression System
Have a certified kitchen hood system professional inspect your kitchen hood system every 6-months and immediately after any major hood/duct cleaning. The system should be inspected overall and tested to verify that it is fully operational. Keep in mind that menu, preparation, and layout may require an update to your system. Any updates, again, require a professional.
While a professional should service, test, inspect, recharge or repair a system, NFPA asks system owners to perform a monthly inspection. This inspection is for visible problems with the kitchen hood system.
Check the following during your monthly visual inspection:
- The extinguishing system is in its proper location.
- The manual actuators are unobstructed.
- The tamper indicators and seals are intact.
- The maintenance tag or certificate is in place.
- No obvious physical damage or condition exists that might prevent operation.
- The pressure gauge(s), if provided, is in operable range.
- The nozzle blow-off caps are intact and undamaged.
- The hood, duct, and protected cooking appliances have not been replaced, modified, or relocated.
Supplement Your Kitchen Hood System
K-Class fire extinguishers are used to protect against kitchen hazards without leaving residue. These extinguishers are a great supplement to kitchen hood systems and should be present in any commercial cooking environment.