4 FM quick reads on fire sprinkler
1. Fire Sprinkler Maintenance Steps
Just because the toilets are flushing and the taps are running without issue does not mean it is safe to presume the water supply to the fire sprinkler system is good to go.
Proper sprinkler operation is only ensured through proper and routine maintenance of the system. It's like flossing your teeth — you just have to do it. But when you skip a flossing you don't risk getting caught on the wrong end of a lawsuit or have imperiled lives, so it behooves facility managers to stay on top of their maintenance.
One step is a visual inspection of the sprinkler heads. These can fail to operate due to being painted over, clogged or blocked, says Chris Jelenewicz, program manager, Society of Fire Protection Engineers, in a recent Building Operating Management article. He has even seen a situation where a dropped ceiling was installed without moving the location of the sprinkler heads below the new ceiling heights.
Another step is the main drain test. After establishing a baseline pressure reading, subsequent readings will show if there's a significant drop in pressure. Drops in pressure could be caused by partially shut valves in the underground supply, which would starve the fire sprinkler system of adequate pressure while still seeming adequate in other applications, such as toilet flushing. Another cause could be corrosion in the system, which would interfere with moving high volumes of water at high pressure, he says.
Proper documentation is another important component of testing. Record what tests were conducted when, what the findings were and what is the proposed course of remediation for any issues uncovered.
Hopefully, the fire sprinkler system will never be called into action. But — to borrow the catch phrase from a certain insurance agency — in the event of a fire you won't want to hope the fire sprinkler system is ready. You'll want to know so.
Find the article here.
2. High Volume Low Speed Fan and Sprinkler Operation
High volume low speed fans (HVLS) were invented to keep cows cool in barns, but they've been increasingly adopted in the commercial facilities realm. They can move a lot of air with very little power. Plus they look cool, it's this huge fan, with some models having a kind of industrial chic thing going on.
Dan O'Connor, chief technical officer with AON Fire Protection Engineering, recently spoke on HVLS' impact on automatic fire sprinkler systems for NFPA's Fire Protection Research Foundation. In his presentation, High Volume Low Speed (HVLS) Fan and Sprinkler Operation Research Program Phase II, the scenario he spoke on was a warehouse setting, with boxes of goods stored on racks.
At the heart of the findings of his research is that if the fan or fans are not shut off during a fire, the automatic fire sprinkler system will extinguish the fire, but not before some significant damage has occurred. In one scenario tested with no fan-shut off, between five and 12 pallets were damaged and the fire jumped aggressively across an aisle. In the "fan on" tests, 12 sprinkler heads went off.
In contrast, when the fans were shut off, between a half and two and a half pallets were damaged and only four sprinkler heads activated. Now there were a lot of very specific parameters that you'll have to check out the original research for, but the conclusion was that sprinklers can protect with fan shutdown no later than 90 seconds after waterflow of the first sprinkler. It can take a fan up to a minute to stop rotating after it's shut off. Acceptable ceiling height depends on sprinkler type.
From this research the following proposals are being made for NFPA 13, under the General Design Criteria.
- Fans can have a max diameter of 24 feet.
- The fan has to be centered between four adjacent sprinklers.
- The vertical clearance from HVLS fan needs to be a minimum of 3 feet.
- All HVLS fans have to be interlocked to shut down upon receiving waterflow signal.
High Volume Low Speed (HVLS) Fan and Sprinkler Operation Research Program Phase II
3. Health Care Fire Sprinkler Code Considerations
Here are some fire sprinkler codes to keep in mind when thinking about fire safety in health care occupancies.
In 1991, NFPA 101 mandated automatic sprinklers in new health care occupancies. In the 1996 edition of NFPA 13: Standard for the Installation of Sprinkler Systems, quick response automatic sprinklers were required for all light hazard occupancies including health care.
The unique feature of quick response sprinklers is the faster thermal response to heat. These sprinklers will activate three to five times faster than a normal response automatic sprinkler. This translates to a much smaller fire size at the time of automatic sprinkler activation. Smaller fires generate less heat and smoke.
Renovation, modifications, reconstruction and additions also require the installation of automatic sprinklers. The reliability and robustness of automatic sprinkler protection is addressed in NFPA 101, NFPA 13 and NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems.
NFPA 101 requires the automatic sprinkler system to be electronically supervised and designed in accordance with NFPA 13. NFPA 25 addresses the required inspection, testing and maintenance of all components of the system. The electronic supervision increases the reliability of the automatic sprinklers in health care occupancies. (Most other occupancies do not require this electronic supervision.)
Proper hydraulic design as required by NFPA 13 will provide the robustness to address the typical fire challenges in a health care occupancy. Recent NFPA automatic sprinkler fire data shows that, in sprinklered health care facilities, 99 percent of the fires are contained to the room where the fire started.
4. Fire Sprinklers Statistics in Commercial Property
In the May 2011 National Fire Protection Association report entitled U.S. Experience with Sprinklers, one trend is the steady rise of automatic fire extinguishing equipment across all property types. The term "automatic fire extinguishing equipment" is misleading, says the report, "because most such equipment is designed to control fires and not to fully extinguish them."
In educational property, automatic fire extinguishing equipment was reported in 39 percent of fires between 2005 and 2009, compared to 24 percent between 1994 and 1998. In office space, it rose from 25 percent to 33 percent in the same time periods. In health care, it went from 58 percent to 64 percent.
In a few property types for fires reported between 2005 and 2009, fire sprinkler systems were reported in about half of them. These include dorms and barracks (51 percent), prisons and jails (50 percent), hotels and motels (49 percent), and manufacturing facilities (48 percent).
In every other property type with reported fires, sprinklers were not reported in at least 60 percent of the fires. Office fires between 2005 and 2009 reported a 30 percent sprinkler presence and educational properties reported a 34 percent presence, which makes up the majority of the automatic fire extinguishing equipment presence reported in both property types.
Find a copy of the U.S. Experience with Sprinklers report at http://www.nfpa.org/assets/files/PDF/OS.sprinklers.pdf
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