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TRVs and Alpha2s, Yes, No, Maybe

cnmdesign Member Posts: 102
edited September 2018 in Radiant Heating
My 30x50 1964 ranch has a roughly 150 ft long straight through run with approx 90 ft of Base Ray CI radiators running on one centrally located T-stat.

Is it possible or feasible to add one centrally located TRV (k-value) to the system (making it one big radiator) to help improve the operation of the new Alpha2?

Have lived here for over 22 years, never had a problem with uneven heating through out the house with the old system.
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  • EYoder
    EYoder Member Posts: 60
    If I'm following you right its all in series? Wouldn't it be unbalanced with low flow as the trv opens up?
  • SuperJ
    SuperJ Member Posts: 605
    The Alpha 2 is pretty efficient and low wattage even running at a constant speed. I don't think it goes over 45watts on high. So I don't think you need to optimize for the pump's sake. Better to optimize for efficiency overall, or comfort.

    @EYoder is right, if you throttle flow with a TRV you'll get unbalanced heating. Better to vary the temperature than flow in your case, but if everything is running great maybe you don't have to do anything. The first rads will get heat but there won't be any left for the last ones if you drop the flow. There are ways to use TRV with diverter T's, so that you could zone out the system if you switched to home run or diverter T's. But you would be doing a bunch of work that may not be necessary since you say you have very even heating already.

    You might be able to add an outdoor reset to allow you to run constant circulation at a temperature than matches your load.