Are there any requirements pertaining to mixing fire sprinkler k-factors or temperatures in the same room?
We often come across unit heater placement, so at least on the temperatures I suspect that mixing in the same room happens fairly commonly to accommodate heat sources. Posted anonymously by a member for discussion. Discuss this | Subscribe
7 Comments
Corey
2/14/2019 10:02:52 am
Yes, you can mix temperatures within the same area. See NFPA 13, 2016 edition 8.3.2.5 for more detail.
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Dan W
2/14/2019 10:24:14 am
If you are using the different K-Factors to minimize over discharge a system, then not allowed (23.4.4.9.2-16'). 23.4.4.9.3 & 23.4.4.9.4 allows different orifices within small rooms (exposure protection & directional spray sprinklers) with the Annex explanation giving a little more insight.
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PETE
2/14/2019 10:24:22 am
Mixing K-factors is acceptable, however, you will want to either designate areas that certain K-factors are to be used, or be very knowledgeable about fluid dynamics. If you have one K-factor in one area, and another K-factor in another area- both areas should be calculated. This also applies to standard and extended coverage in portions of systems.
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PETE
2/14/2019 10:30:44 am
I should add, after reading DAN W's comment above: the example I gave was a directional nozzle deluge system for a pumping station near an exterior dock; in which non-flammable non-combustible liquids were being pumped- mainly ammonia.
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ZS
2/14/2019 01:49:16 pm
Adding to what others have said.
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Dan W
2/14/2019 05:52:42 pm
For the FR/QR/SR comment, it can be done in accordance with 8.3.3.5 '16. This has saved me on a couple of projects with EC sprinklers.
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Franck Orset
2/19/2019 11:06:26 am
Mixing K-factor is not a good idea, unless you have good reasons for it (such as a deluge system where the K factor may different depending on the area for the entire surface coverage, but this is not a sprinkler system...).
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