Dual boiler P/S piping ?

Gary Jansen_3

Did we ever find out what program he used to do the drawings? Thanks, Gary

Ron Schroeder_3

Dual boiler P/S piping ?

Hi Wallies,

I was thinking of a possable P/S piping arangement for dual boilers to prevent too high of return temperature (and short cycling) to the second boiler when both are firing.

I was thinking of 4 closely spaced Tees with the first boiler on Tee 1 and 3 and the second boiler on Tee 2 and 4. Would this work without interaction?

Thanks

Ron

Mark Eatherton1

Instead...

WHy not pull one set of tees of the primary and feed the two boilers in parallel off of that. Then they'll both see the same return and supply water temps.

Don't forget to provide some means of low temp protection for the boilers.

ME

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Boilerpro_3

And don't Forget

check valves on each boilers outlet. If only one boiler pump is running, a large amount of water can backflow through the off boiler. Also, you want to pump the boilers individually so that you don't get cold return water pumping through an off boiler and mixing down the temp of the hot water coming off the on boiler.

Boilerpro

Paul Rohrs

Here is an example of 5 boilers

in a parallel primary loop. This is essential especially if they are condensing boilers. Definately want to read "Radiant Precision" from the RPA and the mind of John Siegenthaler.

Regards,

PR

Ron Schroeder

Hi Mark,

The reason for thinking about the 4 Tees was to use a pre-made copper manifold for the Tees.

Flo-checks of check valve circs. would be used of course.

Thanks,

Ron

Mark Eatherton1

I see...

Well then I guess you could do it like this then...

ME

jeff_51

ya thats the way we do them

with tekmare outside controller and twinning control to cycle each boiler equally so primary boiler is switched back and forth between the boilers.

hr

What about

this?

hot rod

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Ron Schroeder

Hi Mark,

That's exactly what I was thinking of doing. When "thinking like water", I think it will still work even if there is some difference in restriction and flow rate between the two boilers.

Ron

Brett O'Connor

Ron

Mad Dog_2

This place really is remarkable!!!!!!!

One question is answered with several smart and viable options. Mad Dog

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Mark Eatherton1

Nice drawing Brett..

whose program?

ME

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Mark Eatherton1

Negligable...

just make sure you put checks on the outlets of the pumps serving the boilers.

ME

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Bob Knebel

Question for Brett

Very nice schematic Brett! I have a question. If P4 is a variable speed injection pump serving the secondary loop for the three radiant zone pumps, why not just close the boiler loop and draw off the boiler loop with the injection pump (and DHW or "hot zone" pumps)? That would eliminate the need for the primary loop shown near the top of your schematic. I think Hot Rod's schematic shown above may be a more straight-forward and less expensive way to perform the task. Maybe I'm not understanding your schematic. What am I missing here?

Thanks.....Bob Knebel / Radiant Engineering

Floyd_8

In that drawing, both boilers

are seeing exactly the same temps. AND if one boiler springs a leak or goes down for any reason you are not SOL......
simply valve out the offending boiler and at least you can run on one. Also with that drawing you have the potenial to run two different temps. One high temp say for baseboard and one low say for radiant.

Floyd

Maine doug

Hey Brett

what did you use to make the cool drawing??

Paul Rohrs_4

Visio

He is using the same Visio (Microsoft) program that I use. It also looks as if he has a disc of stencils from Wirsbo that are very nice to construct these pictures with.


Regards,

PR

Paulr@biggerstaffradiantsolutions.com

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