Darcy weinbach calc procedure

[rrewis]

Does anyone use the Hydracad stand alone calculation program? If so can you tell me the procedure. The program doesn't differentiate between the anti-freeze portion of the system and the non anti-freeze portion.

Thanks
Russell Rewis

 

[TravisMack]

Russell:

The program does not differentiate at all with heated and unheated areas. That is one of the drawbacks of the DW method. You could in theory do an equivalent K-calc, like we used to do with in-rack systems.

Unless it really kills me on the calcs, I just typically treat the entire thing as it is in the freezing area. But, if you are in a really cold area, you will be looking at some large swings in pressure.

Also, don't forget to adjust your k-factor. HASS automatically adjusts the k-factor, but Hydratec does not do that. There was a paper by Ken Isman, PE that gave the formula for doing the k-factor adjustment for AF systems.

Give me a call if you have any more questions that I can clarify. I do A LOT of antifreeze systems each year. More than I care to, but that is what the customers want in some areas.

Travis Mack
MFP Design, LLC

 

[rrewis]

Thanks Travis. I would very much like to talk to you about this post. I'm not experienced on how to best use this forum so I do not know how to connect with you off this forum.
Thank you very much,
Russell

 

[SprinklerDesigner2]

"There was a paper by Ken Isman, PE that gave the formula for doing the k-factor adjustment for AF systems."

Looked around the web and couldn't find it.

Where was it published?

 

[rrewis]

The Hydratec calc program does adjust the K-Factors. I can successfully do a DW calc with this program as well of course a HW calc. My problem is doing a correct calc of the anti-freeze in DW and the non-anti-freeze portion of the system suppling the anti-freeze portion of the system with HW. If the complete system is done with DW there is a large difference in the results as far as required psi.

Russell

 

[TravisMack]

Russell:

I sent an email to your email address at Brown Sprinkler. I recognized your name from the AFSA forums.

Travis Mack
MFP Design, LLC

 

[KGBeast42]

Travis,

If it is possible I would also like to get a link to this paper. The AHJ's in our area have just started requiring the DW calc.

Chad Johnson
Flow FIre Protection

 

[TravisMack]

KG:
It is frowned upon to post email addresses on this forum so that it keeps the spammers away. However, if you go to AFSA.s website and search for designer companies in AZ, you will find contact information. Shoot me an email and I can send you a PDF of the article.


Travis Mack
MFP Design, LLC