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Radiant floor heating pump calculator

Is there a website where I can plug in my radiant floor information ( pex tubing loops, manifold and supply? return piping) and find out what circulation pump I should be using.


  • hot_rod
    hot_rod Member Posts: 21,898
    Two steps
    Determine the loop pressure drop, Most all of the radiant tube manufacturers have those charts online. For instance 1/2 Pex, 300’ long what is the pressure drop

    Then the pressure drop in the boiler and piping

    How many btu or gpm?

    Next use pump curves to select the circulator based in the gpm and head required. A heat load calc gives you the btu load requirement.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,618
    edited April 2020
    Here is the best information available for a non-engineer to answer your question.


    I went to a seminar in the late 1970s to better understand how to answer your exact question. At that time, I did not even know that I needed to know how to answer the question. i went to the same seminar each year for 3 years (@$125.00 per) and each year I learned a little bit more.

    In the 1990s I went to @DanHolohan seminars whenever I could. And then I got to be good at answering your question. So you need to study the booklet more than once to get the answer. Or you will need to find the expert in your area who can give you the right answer. The local plumbing & heating supply house can guide you to the correct professional.

    it all depends on how soon you need the answer.

    Are you Designing or Trouble shooting an existing?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • johnwalcott
    johnwalcott Member Posts: 2
    Thank everyone for the help. Looks like I have some research to do.
  • SuperTech
    SuperTech Member Posts: 2,127
    > @DanHolohan said:
    > Thanks, @EdTheHeaterMan I wrote that Zoning Made Easy booklet years ago. I was at a meeting at B&G's place in Morton Grove, Illinois where I submitted the draft of the booklet. An engineer there read it over and then told me that my writing style made him want to vomit. It offended him as an engineer. I explained that I hadn't written it for him.
    > They paid me. It's a lovely memory. ;-)

    This made me smile and laugh. I needed that!
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,492
    Retired and loving it.