Question Regarding SprinkCalc Output For Antifreeze Systems > 40 Gallons

[stookeyfpe]

We are currently reviewing a Group R-2 apartment building where the FP contractor is using an antifreeze system to protect the Reception Center/Leasing Office attic of the Type V construction building. The volume of the system is > 40 gallons, and we are enforcing Section 22.4.4.5.1 of NFPA 13, 2010. When calculations were requested for the antifreeze system, the FP contractor produced a set of calculation from Tyco FP Products. The calculation info. portion of the report indicates that Darcy-Weisbach is employed, the antifreeze solution (48% glycerine in this case), the density and its kinematic viscosity.

What we are troubled by is what the software produces versus the requirements of Section 22.4.4.5.1. As I read this section, the software is supposed to generate a Moody diagram based on the pipe's design roughness factor and an adjusted K-factor. For this to be determined, the Reynolds Number needs to be calculated to determine if the flow is laminar or turbulent, because the friction loss is influenced by this.

The only results we see is a conventional hydraulic calculation based on Hazen-Williams. We can't find anything in the calculations that creates an adjusted K-factor for Q at different pressures based on the requirement in Section 22.4.4.5.1.

Are we missing something?

I appreciate your assistance.

 

[TravisMack]

Ken Isman did a paper on adjusted K-Factors for anti-freeze calculations around 2007. You may be able to find it on the NFSA website. It is basically the formula that all of the programs are using from my understanding.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[cdafd]

Oh no Texas is going to freeze, Stookey asking a question

I have asked a contractor to calc per Darcy. But did not know how to interpret what they gave me

http://www.vikinggroupinc.com/techarticles/frictionloss.pdf

 

[stookeyfpe]

Travis:

I tried to find it on the NFSA website. Since I'm not a member I was pretty much out of luck. I'll call them tomorrow.

CDA:

Thanks for the paper.

 

[cdafd]

Looked at the calculations today and appears in the note section they showed the K factor adjustments and showed in other places roughness, vel, friction factor