What Are Home Fire Sprinkler Systems?
Using quick response sprinklers and approved piping, homes can be built or even retrofitted to include low-cost automatic sprinkler systems connected to the domestic water supply.- Sprinkler systems offer advantages to the homebuilder:
- A low-cost reliable safety option that would attract many buyers.
Trade-offs between sprinklers and code requirements that can result in lower construction costs, more units per area of land, etc. For homeowners, the advantages include assurance of a safer environment for their families, protection of their investment and irreplaceable family possessions, and lower insurance rates 5 to 15 percent. Advantages of Newly Designed Home Sprinkler Systems
Fast Response
Residential sprinklers, listed by Underwriters Labs, are now
available. They are designed to respond to a fire much faster than
currently available standard commercial and industrial sprinkler
systems. The new home sprinklers react automatically to fires more
quickly because of their improved sensitivity.
Low Cost
At the present time, cost of a home sprinkler system is targeted at
approximately $4.00 to $5.00 per square foot of occupied space where there is a public water supply available. It is
hoped that the cost will decrease as the use of home fire protection
grows. It is possible to integrate sprinkler systems in new construction, or in retrofitting existing homes.
Small Size
For residential systems, the sprinklers will be smaller than
traditional, commercial, and industrial sprinklers, and can be
aesthetically coordinated with any room decor.
Minimal Installation Work
When homes are under construction or being remodeled, a home sprinkler system will require minimal extra piping and labor.
Low Water Requirement
These systems will require less water than the systems installed in
industrial or commercial establishments and can be connected to the
domestic water supply.
Piping Requirements
In addition to metallic pipe, the use of plastic pipe has brought
down the cost of installation in new construction and the retrofit of
existing structures.
Sprinklers
Based on the unique floor plan of the home you’re
building, the sprinkler designer determines the piping design and
the appropriate number, type and layout of sprinklers along the
piping. Since sprinklers cover a minimum 12 x 12 foot area,
while extended sprinklers can cover up to a 20 X 20 foot area,
in many rooms you’ll have a single sprinkler.
Larger areas will be protected by additional sprinklers or special
extended coverage sprinklers. For example, in a typical unfinished
basement, three pendent sprinklers would be used to protect the
far sides of the area and near the center stairway. The NFPA 13D standard permits positioning sprinklers
in basements to anticipate future ceiling finishing – a flexibility
selling point for your buyers who are thinking ahead. If you finish
the basement, concealed sprinklers can be used immediately. When you get up into the finished areas of the home,
concealed sprinklers can be used in the ceilings. Wall-mounted,
semi-recessed sprinklers are used when you want to avoid placing
pipes in an unfinished attic.
Concealed Sprinkler Sidewall Sprinkler Pendent Sprinkler
Typical
Water Sprinkler Supply
Here’s what you’ll have
with a typical stand-alone system. The water supply for the sprinklers
usually comes from the household water main, but can also be supplied by a water tank and pump. There will be a “T” connection
between the main and the water meter, feeding the sprinklers.
This is called the “riser.”
The riser is really the brains of the system. It includes the
pressure gauge, a flow switch and a backflow valve (where required)
and the test and drain assembly. NFPA 13D doesn’t require
a flow alarm, but your local codes might.
The flow switch monitors any water flow through the system and
is wired to an inside bell. The flow switch can also be wired to
an outside horn or strobe to alert neighbors to sprinkler activation
in case fire strikes when no one is at home. The switch can also
be tied in to a monitored security system.
Backflow prevention devices are installed to isolate the water
used for sprinklers from the water used for domestic purposes,
to prevent any cross-contamination of potable water. Many local
jurisdictions require these.
Backflow prevention devices and water meters reduce the available
pressure for the sprinkler system, however, so when they are used
it is necessary to use larger water taps and meters of at least
one inch or more. Your sprinkler contractor will ensure you have
the information you need to know about taps and meters before you
install the system.
Sources
U.S. Fire Administration. "Residential Sprinkler Systems." U.S.F.A. 14 April 2009. web. 7 May 2009.
<http://www.usfa.dhs.gov/citizens/all_citizens/home_fire_prev/sprinklers/>
Pictures and descriptions for the types of sprinklers and the typical water supply
provided by the Home Fire Sprinkler Coalition. web. 7 May 2009.
<http://www.homefiresprinkler.org/Build/BuildNewDesigns.html>
<http://www.homefiresprinkler.org/Build/BuildwaterSupply.html>