With the inextricable role of sprinklers in fire protection systems, an important consideration to make is how to optimize the efficiency of your sprinkler system. After all, different occupancies have different water supplies, building construction, fire hazards, and will contain different types of equipment or goods. What sprinkler system would suit a document archive versus an industrial facility? One factor you may want to consider is whether or not a water mist system would suit your fire suppression needs over a fire sprinkler system. Water mist systems use less water than sprinkler systems, effectively cool down fires, and mitigate damage to electrical equipment. We will discuss the pros, cons, and more for water mist systems in this blog.
Water mist fire suppression systems release small water droplets, which can size between 10 and 1000 microns in diameter. Water mist systems produce these fine water particles by forcing high-pressure water through specially designed nozzles in the system. Due to this property, water mist systems can deliver effective fire control, while lowering the overall consumption of water. It follows that this would reduce water damage after the event, since less water is used. Not to mention the lower environmental impact from using less water. Also, the smaller droplet size means that damages to electrical equipment and other stored goods are drastically reduced.
Water mist systems come in low pressure and high pressure variations. High pressure water mist systems can work with an operating pressure of up to 200 bar. In comparison, low pressure mist systems operate at 12 bar or less. Generally, the higher the pressure, the smaller the water particles. Particle size is also affected by the type of nozzles used in the system, which can change the particle size and the conical spray angle of the mist. For fire suppression applications, high pressure systems are usually preferable, as they have smaller droplet sizes, higher cooling potential and displace oxygen more effectively.
The working principles behind water mist systems are increasing cooling effects on the fire, displacing oxygen, and wetting fuel surfaces with fine water particles. One major advantage of the atomized water particles is its high surface coverage. Meanwhile, the small particles also attenuate radiant heat on solid fuel fires, while reducing dangerous splashing on oil and grease fires. This means that water mist systems are highly effective for class B fires, which involve flammable liquids. In addition, mist systems can be used to suppress fires caused by combustible materials, like wood, cloth, and paper, and fires caused by electrical equipment, like appliances, wires, and motors.
Water isn’t the exclusive extinguishing agent used in mist systems. Hybrid mist systems are sometimes used, which contain a mixture of air or nitrogen with water to create even smaller droplets. Hybrid systems utilize two separate piping systems to combine the agents. Subsequently, the system is able to cover even larger areas, and enable precise fire control in high-risk environments. The hybrid system excels in industrial facilities, where water mist cools the flames, while the nitrogen effectively suffocates the fire from oxygen.
A water mist system has many key differences with a traditional sprinkler system. For one, Water mist systems use lighter and thinner piping, thus consuming less water. As a direct result, mist systems allow you to save water and utilize municipal water supplies for efficient fire suppression. If you do opt to use a fire pump, you can use a smaller and less expensive pump when you are using a water mist system. Compared to traditional sprinkler systems, water mist systems can use up to 90% less water than traditional systems. When using a low pressure mist system, you can use thin walled stainless steel or galvanized steel pipes, which will further lower the weight of your system. Overall, water mist solutions allow you to save space and operate at a lower cost.
Water mist systems also have applications outside of traditional firefighting systems. Water mist is useful for air and gases cooling, dust control, vehicle or equipment cooling, HVAC humidification processes, greenhouse applications, and more. The atomized water particles released by mist systems wet airborne dust particles, which make it an effective solution for trapping silica dust in constructions sites, or dust that is produced by heavy machinery. This special property of water mist systems also result in reducing smoke levels in the event of a fire when compared to sprinkler systems.
Keep Reading: The Difference Between Standard and Quick Response Fire Sprinklers >>
Dust control with water mist in a manufacturing plant
Some of the disadvantages of water mist systems include higher initial costs, maintenance of water nozzles, and lower fire suppression effectiveness outdoors. When outdoors, high winds may disperse water droplets before they reach the fire. Also, water mist suppression will struggle to suffocate the fire in outdoor or large volume applications.
Compared to traditional sprinkler systems, there are also more design considerations when using water mist systems. For example, some ways to apply water mist protection in your building include local application, total compartment application, zoned application, and occupancy protection systems. Equally important, you must also account for the room size, the type of fire, ventilation, and the shape of the mist itself. Water mist systems are more effective the closer the nozzles are, unless you opt for a total flooding solution.
The NFPA code for water spray systems and water mist systems is the NFPA 750. According to the NFPA, water mist systems can be effective on both liquid fuel and solid fuel fires. With liquid fuels, large water droplets will agitate the surface of the fuel and increase burning intensity. At the same time, having larger droplets may help with wetting solid fuel fires. According to the NFPA standard, water mist systems have proved effective in controlling many types of fires. This includes the following:
The NFPA 750 emphasizes the importance of maintenance for water mist systems. Periodic inspections and tests make sure that the system is in good working condition. They recommend that inspections consist of the following:
In conclusion, water mist fire suppression systems offer a highly effective, water-efficient alternative to traditional sprinkler systems. They provide optimal fire control with reduced water damage and environmental impact. While these systems come with certain challenges, such as higher initial costs and design considerations, they offer significant advantages, including enhanced protection for sensitive environments like industrial facilities and electrical equipment.
Ultimately, a proactive approach to fire safety—incorporating proper system design, regular maintenance, and staff training—is essential to minimize the risk of fire and ensure that your facility is prepared for emergencies. By adhering to fire safety codes and regulations, you create a safer, more resilient environment for staff. At FireAlarm.com, our expert team is ready to assist you with system design, installation, inspection, and maintenance services tailored to your needs. Reach out to us today to discuss how we can get your business compliant with the codes.
$3,920.58
$4,555.19
$307.62
$16,469.89
$11,821.95
$157.28
$85.33
$144.93
