LCREP
Specifier/Regulator
- Feb 14, 2004
- 837
I was at NFPA annual meeting last week and sat in a seminar on this topic. It looks like this can be a big problem for buildings that have these fans. More work needs to be done but based on the info below, IF you have a building owner that wants your install one these fans, tell them NO!
The test below was done with standard sprinklers, NOT ESFR, take a look at how many heads activated during the test. Keep in mind ESFR design is only 12 sprinklers!
The key is to shut down the fan very early in the fire. Fire detection looks like the way to go. Sprinkler water flow switch tied to the fans are too slow. As to spacing, type of detection system, etc. that still needs to be worked out.
If you do not know what these fans are take a look at these mfg web sites:
The May/June 2008 issue of NFPA Fire Journal has info on this topic too.
From the testing by XL Global Asset Protection conducted at UL:
Test 1 was conducted on 15 ft (4.6 m) high palletized storage of a Group A Plastic commodity positioned so that the ignition was located between four ceiling sprinklers with the movable ceiling located 25ft (7.6 m) above the floor . The sprinklers were 286°F(141°C) rated, K-11.2 with a standard response operating link, on a 8 ft x10 ft (2.44 m x 3.05 m) spacing. The sprinklers were arranged to operate at flowing pressure of 18.4 psi upon activation creating a density of 0.60gpm/ft² (24.42 L/min/m²). Ignition was accomplished while the fan was moving air in the downward direction at the fifty percent (50%) power setting. The first sprinkler operated at three minutes twenty-six seconds (3:26) after ignition and the fan power was shut off and the fan was allowed to coast to as stop. A total of seventy-three (73) ceiling sprinkler operated between3:26 and 7:35. The test was terminated eight minutes after ignition. The post test observation and analysis of the test array indicates that the fire spread to the extremities of the test array .
The second and third tests were conducted on 12 ft (3.7 m) high palletized storage of a Class II commodity positioned so that the ignition was located between four ceiling sprinklers with the movable ceiling located 22 ft (6.7 m) above the floor. The sprinklers were 155°F (68°C) rating, K-5.6 with a standard response operating link, on a 10 ft x 12 ft (3.05 m x 3.7 m) spacing. The sprinklers were arranged to operate at a flowing pressure of 18.4 psi upon activation creating a density of 0.20 gpm/ft² (8.14 L/min/m²).
Test No. 2 was a baseline test and the fan was not used. Ignition was accomplished and the first sprinkler operated at one minute fourteen seconds(1:14) after ignition. A total of twenty-one (21) ceiling sprinkler operated between 1:14 and 3:40 . The test was terminated thirty minutes after ignition. The post test observation and analysis of the test array indicates that the fire did not spread to the extremities of the test array.
Test No. 3 had the fan in operation. Ignition was accomplished while the fan was moving air in the downward direction at the fifty percent (50%) power setting. The first sprinkler operated at one minute fifty-seven seconds(1:57) after ignition and the fan power was secured at that time. A total of twenty-six (26) ceiling sprinkler operated between 1:57 and 3:51 . The test was terminated thirty minutes after ignition.
The post test observation and analysis of the test array indicates that the fire spread to the extremities of the test array. High Volume/Low Speed Fans and Sprinkler Discharge Based on some exploratory testing by GE Gap Services, the Foundation has been asked to develop a project to explore the effects of these fans, common in industrial occupancies, on sprinkler discharge.
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Fire Sprinklers Save Firefighters’ Lives Too!
The test below was done with standard sprinklers, NOT ESFR, take a look at how many heads activated during the test. Keep in mind ESFR design is only 12 sprinklers!
The key is to shut down the fan very early in the fire. Fire detection looks like the way to go. Sprinkler water flow switch tied to the fans are too slow. As to spacing, type of detection system, etc. that still needs to be worked out.
If you do not know what these fans are take a look at these mfg web sites:
The May/June 2008 issue of NFPA Fire Journal has info on this topic too.
From the testing by XL Global Asset Protection conducted at UL:
Test 1 was conducted on 15 ft (4.6 m) high palletized storage of a Group A Plastic commodity positioned so that the ignition was located between four ceiling sprinklers with the movable ceiling located 25ft (7.6 m) above the floor . The sprinklers were 286°F(141°C) rated, K-11.2 with a standard response operating link, on a 8 ft x10 ft (2.44 m x 3.05 m) spacing. The sprinklers were arranged to operate at flowing pressure of 18.4 psi upon activation creating a density of 0.60gpm/ft² (24.42 L/min/m²). Ignition was accomplished while the fan was moving air in the downward direction at the fifty percent (50%) power setting. The first sprinkler operated at three minutes twenty-six seconds (3:26) after ignition and the fan power was shut off and the fan was allowed to coast to as stop. A total of seventy-three (73) ceiling sprinkler operated between3:26 and 7:35. The test was terminated eight minutes after ignition. The post test observation and analysis of the test array indicates that the fire spread to the extremities of the test array .
The second and third tests were conducted on 12 ft (3.7 m) high palletized storage of a Class II commodity positioned so that the ignition was located between four ceiling sprinklers with the movable ceiling located 22 ft (6.7 m) above the floor. The sprinklers were 155°F (68°C) rating, K-5.6 with a standard response operating link, on a 10 ft x 12 ft (3.05 m x 3.7 m) spacing. The sprinklers were arranged to operate at a flowing pressure of 18.4 psi upon activation creating a density of 0.20 gpm/ft² (8.14 L/min/m²).
Test No. 2 was a baseline test and the fan was not used. Ignition was accomplished and the first sprinkler operated at one minute fourteen seconds(1:14) after ignition. A total of twenty-one (21) ceiling sprinkler operated between 1:14 and 3:40 . The test was terminated thirty minutes after ignition. The post test observation and analysis of the test array indicates that the fire did not spread to the extremities of the test array.
Test No. 3 had the fan in operation. Ignition was accomplished while the fan was moving air in the downward direction at the fifty percent (50%) power setting. The first sprinkler operated at one minute fifty-seven seconds(1:57) after ignition and the fan power was secured at that time. A total of twenty-six (26) ceiling sprinkler operated between 1:57 and 3:51 . The test was terminated thirty minutes after ignition.
The post test observation and analysis of the test array indicates that the fire spread to the extremities of the test array. High Volume/Low Speed Fans and Sprinkler Discharge Based on some exploratory testing by GE Gap Services, the Foundation has been asked to develop a project to explore the effects of these fans, common in industrial occupancies, on sprinkler discharge.
****************************************
Fire Sprinklers Save Firefighters’ Lives Too!