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Pipe size, layout, and heat loss questions
I am switching from an all electric house to a gas boiler. I plan to run this system @ 120 degrees. The above image is my planned piping layout. If there are any changes I should make, please let me know.
My specific questions are regarding pipe size.
1) The boilers inlet and outlets are 1". Is there a formula I can use to determine what the main supply and return should be? Should I keep it say 1" until after the hydraulic separator, then increase to 1.25-2", or what?
2) The home run manifolds available seem to only come in 1" or 1.25" trunk, so that makes choosing the pipe size off of the main supply/return either 1/1.25", once I have the formula, correct?
3) Once at the home run manifolds I plan to transition to 1/2" Uponor expansion pex. Again based on what is sold, it seems that 1/2" pipe size is already decided for me. Only option would be to decrease the size to 3/8", which does not seem appropriate in any situation.
My delta T/temp difference is 63 degrees, using 7 degrees as my outdoor temp and 70 as my indoor temp. The 7 degrees was used based on the 99% rule. (This is one variable needed for pipe sizing?)
I drew my house floor plan, you can take a look here: https://imgur.com/a/p9TT3IV
I am currently calculating my room by room heat loss, but heat loss is a tricky beast for someone doing it for the first time. I currently have a total loss of 44,384 BTUs calculated, however, I am not exactly sure all my calculations are correct, especially my air infiltration and slab loss calculations. I have an entire excel spread sheet I attached to this post.
Appreciate any help, thanks!
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