Pushing the envelope?

Mark Eatherton1

Ran into a problem I never thought I'd see. Not having enough tube and or manifolds to make it from one end of a building to the other, and back.

Using 600 foot rolls of PEX, we normaly limit our runs to 300 feet. However, it was 450 feet round trip, for one loop. It's an airport hanger, 15,000 feet. Not wanting to waste tube, we utilize 600 foot rolls and keep our circuits within 300 feet length. Usually...

So, I whip out my Hydronic Pros software and model the hanger using 600 foot circuits of 5/8" tube with an individual Grundfos pump pushing fluid for each manifold, and by golly, the math said it will work!

Just to be safe, I called Master Siegenthaler and ran it by him before we commited. He said he's done large open expanse warehouses with 500 footers 18 to 24" OC before and had no probelm, and that if his software said it should work, it WOULD work, so thats what were doing.

The guys spend much more productive time on the grade and less time worrying about breaking it off in time to get back to the manifold. Speaking of manifolds, there will be half as many ports as there would have been too.

The tube is 18" OC, and it IS a commercial building, so I don't think we have to worry about people walking around in their bare feet doing the "Ooooh, Ahhh" test on us.

In the future, I think I'd be tempted to do two heat losses on a building like this. One for the exterior 20 foot band, and one for the interior. Siggy said I could probably have gone to a 24" center with no problems in the middle.

As my good friend John Barba said recently in an article in the RPA Newsletter, "DO THE MATH!!".

You might be suprised what it tells you!

Thanks for the help John!

ME

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Thanks for the stretch exercise, ME

That's the beauty of the HDS of Siggys. Play the "what if" game on every design!

I still feel there is some real valid applications for the 1000 foot or longer loops with reverser.

Think how much real estate and build length you could cover with 1000 foot lengths.

15, 18, and 24" need to always be considered on those commercial jobs also. 600 foot 3/4" loops are my main stay for 10,000 square foot buildings.

hot rod



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Weezbo

ok. let me share ....

Murph'_5

How would it Know ??

The reverser that is.. would it be on a timer during run-cycles or sensor for the water temps coming back?



Murph'

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Mark Eatherton1

Time delay relay

set on recycle from Graingers is how I've done it before. Time cycles depend on length of circuit, but typically run 15 to 20 minutes per direction. It's adjustable so you can fine tune it to your specific situation.

ME

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Josh M.

you know I did a 100,000 square foot warehouse like this and it worked great. If anything I overestimated because the solar gain from all of the overhead lighting contributed almost 800,000 BTUH. Something to think about when you guys are calculating heat loss on large buildings.