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Vintage wall hung radiator help

Hi folks. I have a cast iron radiator my client would like in her bathroom. Question is, which is the best orientation for the inlet  and oulet to be. I know regular cast iron radiators go in and out the bottom for the best heating efficiency. I have seen them piped in the bottom and out the top side, but that heats the radiator on a diagonal, I've seen the thrmal scans to prove it. I'm thinking this one shouls be piped in at out at the bottom sides oriented as in the last picture. Any help.is appreciated


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,838
    How large is the bathroom? Will the EASY install using the existing openings make that radiator provide enough heat for that room, even if it is only operating at 75% or 85% of the rated capacity at the given operating temperature? This is not "rocket surgery"! If the radiator is not large enough for the space, then you will need a bigger radiator, however if the room is of a size that the radiator will do the job, then make it easy for your self. The only way to answer your question is to have the bathroom load calculation numbers and convert the EDR of that radiator to BTUh at the system operating temperature.

    I'm guessing that the radiator with a top and bottom connection will be just fine. Will it look fine too? Only the homeowner will be able to say that.

    Mr. Ed
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • ShacktoCastle
    ShacktoCastle Member Posts: 2
    edited March 2023
    Mr Ed, you may have misunderstood my question. I am not asking for help on sizing the radiation,  I have the cast iron radiator btu by surface area and tube length, I have installed many. It makes A LOT of difference BTU wise on how it is connected. The way it was hooked up was in the bottom and out the top, ugly and the diagonal.above the input will be cooler, by a lot. There are 22 tubes that run one direction including the main tubes. There are 4 that run the other. The water needs to "roll" on the inside, circulate with the temp difference of the incoming supply. Going in and out at the bottom sides of this one I am not so sure the upper half will heat well. I figured someone here may have run into these, or have a good head for thermaldynamics and could give an answer. Thanks for taking the time to post a response. 
  • Alan (California Radiant) Forbes
    I'm used to seeing those as in at the top, out at the bottom, either same side or opposing. As the hot water gives up its heat, it will settle slowly and go out the bottom, heating the radiator evenly.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • pecmsg
    pecmsg Member Posts: 4,849
    Is it just me but I see that style as Ceiling mount. 
  • leonz
    leonz Member Posts: 1,130
    edited March 2023
    It is a ceiling or wall hung radiator
  • reggi
    reggi Member Posts: 511
    edited March 2023
    Edit: I'm not sure what country it's in... their water might run differently,⛲
    Unless this is wrong I'd say it's right 🥱

    One way to get familiar something you know nothing about is to ask a really smart person a really stupid question
  • random12345
    random12345 Member Posts: 469
    edited March 2023
    @ShacktoCastle It took some digging, but I believe what you have there is a Rococo Wall Radiator made by the American Radiator Company. Here is a catalog from 1908 explaining how to install them:


    See pages 115-116, and 211-218.

    Here is a later catalog from 1910:


    See pages 107-108, and 206-213.