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taco rmb-1 question

bovide_4 Member Posts: 161
Total heat loss of house = 57,000 btu
Heat emitters = radiant, 13 loops of 1/2" x 200' max. pex
mostly staple up w/plates and insulation.
Piping: P/S with a taco rmb-1

The connections on the radiant supply and return piping are 3/4". I want to pipe in two sets of 6 loop manifolds, with a zoning circulator on each of the two supply manifolds. Should I keep the loop to the manifolds 3/4", or bump it up to 1", so the closely spaced tees will be 1" x 3/4"?
Wondering if it makes a difference with the supply and return of the mixing block being 3/4"


  • Weezbo
    Weezbo Member Posts: 6,232
    something sounds amiss...

    i tend to wonder why how who what where and when a great deal,....you have an injection system, AND you want to add constant circ is what i read? are you using another bridge off the RMB to constant circ loops or are you saying that you need to use circ pumps for each manifold because of flow rate of a Taco 008?

    over sizing pipe is unlikely to incur financial hard ship so i see no problem with using the next two pipe sizes up for the supply and return header at the field side of the RMB.

    larger pipe sizes at the header see slower flow through that pipe so it works something like a swimming pool :) the BTU's swim in ...if they find a small channel they bunch together more ,if they find a lake they slow down and spread out and take their time giving one another plenty elbow room , that keeps the BTU's habby...because they are Habby, they don't act aggressive... therefore they don't start tearing the place up :)
  • bovide_4
    bovide_4 Member Posts: 161

    your btu description sounds like my twins. what I am doing is exactly that-another bridge.
  • Weezbo
    Weezbo Member Posts: 6,232
    I am somewhat curious *~/:)

    Ask anyone ,Here *~/:)

    Whatever ,...:)

    i like doing what i call "step downs"....

    Ahead of the injection system i like set point return to the boiler...by-pass at stations , variable speed injection systems with remote manifolds with branches or stations run out from there...depends ....

    one of the beauties of pex tubing is that you can do some phenomenal things, economically . what is your heat source? oil fired , gas fired, electric?

    unless your 2600 sq ft building is built like a tunnel though ,i cant quite envision a need for it...

    on radiant in slab or gypcrete you can dial the water temp down further and with the new Wilo circulators soon to be available ,dial the flow rates way down too. Do you have radiant panels as well?

    there are reasons to dial down plate water temps... one might be a slow rolling low temp for establishing a constant low temp, base temp, you are "comfortable with" and point of use "spot specific" radiant panel user dialable comfort zones... for example. What is your thought on further dialing down the water temp? is it a comfort thing?
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