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Boiler Primary Loop Choices

4K views 7 replies 3 participants last post by  Mike Warner 
#1 ·
I'm installing a 110,000BTUH condensing boiler,
with an indirect fired domestic water heater. This
is a closed system with a jacketed indirect-fired
hot water tank. Ascii characters for Tee's and 90º elbows.
Which is the best primary loop design of these five?
The boiler is not shown but is at the top, with three
connections for DHW out, Sys return, and Sys supply.

An attached text file shows the piping configurations.

Any thoughts/opinions are much appreciated,

Mike Warner
 

Attachments

#2 ·
From your description, it sounds like a Weil-McLain unit...am I close? I couldn't open your ascii art file. I just finished a 155 with a 36 gal indirect, I know I don't have all the answers...but I'd willing to help out.

See if you can re-work your ascii file, maybe take a screen shot and post the jpg or bmp.
 
#3 ·
Assuming that this is a residential job, pipe the water heater to have the priority loop and control of the boiler. This is easily done so that the water heater takes priority over heating demand when it needs to make hot water, it usually only takes a few minutes to bring the heat exchanger up to temp.
 
#4 ·
Primary Loop Choices

I'm attaching a picture of my friends system, which corresponds to the first of the five choices in the previously attached text file. I'm wondering if the other four primary loop configurations are any improvement over my friend's working system. Which of the five primary loops in the text file attached in the first post would seem to have the best flow characteristics?

I may post another attachment of a "paint" file with just colored arrows if that would make the other four primary loop configurations more understandable if anyone requests it.

Thanks for the replies so far!

Mike Warner
 

Attachments

#7 ·
From the drawings and my un-professional opinion, I don't think you're altering your flow all that much with any design. I think it's most important to follow the directions and size your pipes correctly. Many times you have to work with what fits your install. Watch the details for example on the W-Mc, the primary loop return legs had to be less than 12" little things like that can trip up a system.

Sorry I can't be of more help.
 
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