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primary/secondary sizing

Brad White
Brad White Member Posts: 2,398
right out of my mouth...

Use flow rate and delta-T to your advantage. If you are not using a ModCon boiler, a little very hot water makes a lot of tepid water for radiant. Oooh.

A low loss header does a number of good things for one cost, one instrument.
"If you do not know the answer, say, "I do not know the answer", and you will be correct!"



-Ernie White, my Dad

Comments

  • george_33
    george_33 Member Posts: 1
    pipe sizing

    Designing primary secondaty job w/ 2-150k boilers 2-55gal Indirects and 8 zones BB OK on the secondary loop pipe sizing looking to keep the primary piping as small as possible to avoid $1000 air seperators Thanks
  • ALH_4
    ALH_4 Member Posts: 1,790
    Flow

    Flow is directly dependent on temperature rise/drop. Widen your delta-T and you may be able to drop the required flow rates. Increase the delta-T from 20°F to 35°F, and you can move 300,000btu/h (assuming this is the boiler output) with 1-1/2" pipe. Will these will be mod/con boilers?

    However, in my opinion, a well-placed auto air vent will work as well as a Spirovent. I'm not sure if this system will have a hydraulic separator or not, but that would be the perfect location for air removal/expansion tank connection. You could also accomplish the same thing with tees.
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