How Do Fire Sprinklers Work?How Do Fire Sprinklers Work?

The sprinkler system was designed in the 15th century by Leonardo da Vinci. He installed a super-oven in his patron's kitchen, and in a comedy of errors, a fire broke out. The sprinkler system caused a flood and destroyed all the food and most of the kitchen.

Commercial, academic, and government buildings were the primary users until 2011, when California ruled all new residential construction must include sprinkler systems. Now they are growing in popularity with landlords and homeowners.

Many people still think they are at a greater risk for fires in public places or hotel rooms. The truth is, the most significant risk for being in a fire is at your home.

Hotels are one of the safest places for fire, mainly because of their fire protection technology. This technology typically includes automatic fire sprinklers.

The good news for homeowners is that sprinkler systems can also be installed in your home. Additionally, if you consider sprinkler systems for your home, just like smoke alarms, insurance companies provide you a discount on home insurance premiums.

Meeting NFPA Standards
When installing a home fire sprinkler, it is essential to meet the National Fire Protection Agency's (NFPA) 13D fire safety standards.

How Do Home Fire Sprinkler Systems Work?
A fire sprinkler system has one job; to put out fires. It does that in three rapid steps:

  1. Detect temperatures between 135 - 165 degrees Fahrenheit
  2. That activates water that extinguishes the fire
  3. It minimizes fire, smoke, water damage, and injuries

We describe each below.

  1. Detect temperatures between 135 - 165 degrees Fahrenheit. A home fire sprinkler uses a network of water piping that maintains water pressure. These pipes are installed in ceilings and behind walls. Since water remains in the lines, the sprinklers are always ready to work. If a fire occurs, the air temperature rises, and the sprinkler heads automatically activate when they detect temperatures between 135 - 165 degrees Fahrenheit.
  2. Activate and extinguish the fire. Individual sprinklers forcefully spray 10 to 25 gallons of water per minute onto flames, which is less than a fire hose. In most cases, this will extinguish the fire. If nothing else, the spray controls the heat and limits smoke or vapor development until the fire department arrives.

    The sprinklers closest to the fire are the only ones that activate. Smoke does not trigger the fire sprinkler head, only heat does.
  3. Minimize fire, smoke, water damage, and injuries. The fire sprinkler head reacts fast, reducing the risk of injury, death, and severe property loss by reducing smoke, flames, and heat. In less time than the fire department arrives, a home sprinkler system can contain and possibly extinguish the fire, reducing property damage and saving lives.

    A home fire sprinkler is much more useful than smoke detectors or a fire alarm, which is why insurance companies recommended having one in your home whenever possible.

Types of Residential Fire Sprinkler Systems
There are two types of sprinkler piping systems used in residential homes. Both are automatic sprinklers, and both use water to extinguish fires, but their water pipe systems are different. The two main types of home fire sprinkler systems authorized by the NFPA 13D standard are:

  1. Stand-alone fire sprinkler systems
  2. Multipurpose fire sprinkler systems

We described the differences below.

  1. Stand-Alone Systems. Both use the home's cold-water supply, but a stand-alone system uses its own piping -- not connected to the home's plumbing pipes. Backflow preventers are necessary as it prevents water from entering areas where it is not needed.

    Copper or flexible plastic tubing is essential for these systems, and if the home uses a water well, a storage tank and pump are necessary to ensure the water supply is sufficient. One issue with stand-alone systems is the stagnant water in the storage tank. Depending on the location of the tank, this can become a health issue without proper maintenance.
  2. Multipurpose systems. Multipurpose systems share the home's plumbing pipes. When water runs throughout the house, it moves through the shared home/sprinkler pipes.

    Multi-use plans are installed during new home construction and are engineered specifically for the home. However, adding multipurpose systems during remodels and additions can be difficult.

All residential sprinkler systems include a flow alarm that sounds when the system is activated. Some of these systems alert the local fire department if activation occurs. Other systems tie into the home's security system. Using a security system combined with water mist systems lowers your home insurance premiums.

How Do Home Fire Sprinklers Work?Automatic Fire Sprinklers

Automatic fire sprinkler systems are networks of pipes that utilize water from your domestic water service line. The system includes fire sprinkler heads strategically placed throughout your house.

Sprinkler-heads are bulbs containing a liquid or dry chemical that, when heated, expands, and breaks the bulb. This action causes the wet pipe system to release water. The pressurized water covers the entire fire.

Most of the time, wet and dry pipe systems use a glass bulb containing a glycerin-based liquid. The glass bulb remains in a closed position until specific temperatures are met. The heat-activated bulb then breaks, and water flows from the now open sprinklers.

happy youtube GIF by Rosanna Pansino

There are three types of residential automatic sprinkler systems:

  1. Wet sprinkler systems
  2. Dry sprinkler systems
  3. Non-water sprinkler systems

We described each type below.

  1. Wet Sprinkler System. Wet pipe sprinkler systems are more prevalent. They always keep water in the pipes. Once they detect fire temperatures, they activate and douse the fire with water.

    Wet sprinklers are easy to maintain and restore after a fire. However, they do freeze in areas prone to low temperatures and can leak if damaged by impact.
  2. Dry Sprinkler System. A dry pipe sprinkler system fills the water pipes with pressurized air or nitrogen instead of water. The air holds the dry pipe system valve closed. This remote valve is in a heated space and will prevent water from coming into the pipe until a fire's heat activates the sprinkler heads.

    When the sprinkler detects a fire, the air escapes, and the dry pipe valve releases. Pressurized water then comes into the pipe and sprays, extinguishing the fire.

    Dry pipe sprinkler systems are ideal in spaces at risk for freezing. Obviously, the sprinkler system will not work if it has frozen water in the pipes.

    Their downside is that they are more complex and harder to maintain. Dry sprinklers also have a 60-second delay before the water reaches the fire. After each use, they must be cleaned and dried, which introduces possible corrosion.
  3. Non-Water Fire Sprinkler Systems. Clean agents are alternatives to water for extinguishing fires. One of the most common clean agents is 3M™ Novec™. Inert gas systems are non-conductive and non-corrosive. That makes clean agents ideal for sensitive areas or areas with unique hazards, such as electronic equipment.

    A gaseous container will have a set amount of pressurized clean agent. This material will discharge through a piping network to strategically place nozzles.

    Some benefits of using non-water sprinkler systems include:

         No residue left behind
         Safe for people
         Eliminates damage from water
         Electrically non-conductive

    Non-water sprinkler systems are mostly in businesses. However, they can be in-home fire detection systems as well. For those who worry about damages water might cause to their home during a fire, the non-water sprinkler system is optional.

    However, the damage water sprinklers cause is minimal compared to smoke and fire damage. Also, a fire hose will often do more harm than the sprinkler system.

Do Sprinklers Detect Smoke?
No. It is essential to know that a fire sprinkler system is not a replacement for a smoke detector. Residential sprinkler systems do not detect smoke and will only operate when it meets a specific temperature.

Regardless, sprinkler systems have become standard features in many homes and office buildings. When properly installed and used correctly, they can save your home from thousands of dollars that fire damage could cause. Also, these systems can save lives.

Do All Sprinklers Go Off at Once?
No. One concern about a home sprinkler system is whether all sprinkler heads will activate at once. The short answer is no. The only sprinkler head that starts flowing water is the one closest to the fire. If the fire is in the kitchen, the kitchen sprinkler will douse the flames.

The ones in your bedrooms or other areas will not activate unless heat is in those rooms too.

Advantages & Disadvantages of Fire Sprinkler Systems
As you can see, a fire sprinkler system's main advantage is that it can put out a fire quickly without human activation, which minimizes damages and can save lives.

However, there are some disadvantages to these fire sprinkler systems as well.

The first issue is cost, roughly $1.35 per square foot. A fire sprinkler system's price varies depending on your home's size, risk profile, and even your home's aesthetics. Additionally, the cost of putting a design into a home that is already built compared to one that is under construction varies greatly.

Another disadvantage to consider is that these systems require maintenance. Once you have it in place, it is vital to have a maintenance routine. Keep the sprinkler heads clean. Also, check the system for damage at least once or twice each year.

Does Homeowners Insurance Cover Fire Sprinkler Systems?
It depends. Your insurer typically will pay to repair or replace your sprinkler system if the pipes or system break suddenly and accidentally due to a covered catastrophe. This Covered Perils by Policy Types article lists the covered perils most standard insurance policies include.

It is not covered if it breaks down over time; that is wear and tear and maintenance, which home insurance excludes. If it malfunctions, it is not covered; that's maintenance too. A warranty would cover mechanical issues, or you can buy an equipment breakdown endorsement to cover mechanical problems.

For example, if your front yard tree falls onto your roof, into your attic, and breaks your system's pipes, you are covered.

You are covered if your system goes off and water damages your furniture, carpet, walls, and anything else, even if a fire did not trigger the system.

You are not covered if the pipes corroded or developed a leak and water dripped out over time damaging your walls and ceiling. That is considered wear and tear and maintenance, which is not covered by home insurance.

Do I Get a Home Insurance Discount if I Install Fire Sprinklers?
Yes. Insurers love home alarms and fire prevention technology because it saves them money on fire damage claims. They will give you up to 5-25% off your home insurance premiums for installing a fire sprinkler system.

Is a Fire Sprinkler for Your Home Worth it?
To summarize, there is a cost to install a home sprinkler system. It is roughly $1.35 per square foot, which can equal the cost of replacing your carpet. However, when it comes to your home's fire safety, the cost-effectiveness seems worth it.

'Hope that helps!

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At your service,
Young Alfred