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Arco Radiators

targetman74 Member Posts: 4
I'm trying to size up a replacement boiler. I have 8 American Arco radiators. I found some info on hear about heating surface based on 240 BTU. My application is hot water and I want to figure out what a mod/con would like.


  • targetman74
    targetman74 Member Posts: 4
    I used an online Calc and came up with 70,000 BTU heat loss.
  • ratio
    ratio Member Posts: 3,605
    I think 240 BTUH is the steam number. The water numbers change by AWT. In any case, you want the book called EDR, available here & other places. I can't guess at your heat loss calc, but the Slant/Fin app for your phone is well-respected here, if you get similar numbers to your original calculation, I'd feel pretty comfortable about it.
  • targetman74
    targetman74 Member Posts: 4
    I have most of Dan's books, but not that one.
  • Steamhead
    Steamhead Member Posts: 16,732
    That's a "small-tube" radiator, represented in "E.D.R." by the Burnham Slenderized.

    But @ratio is right- don't size your boiler to the installed radiation. Do a heat-loss calculation and use that figure to size the boiler.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • retiredguy
    retiredguy Member Posts: 888
    edited June 2022
    Go to the top of the home page and click on "contact us" . Then click on "museum" and scroll down to "radiators". Click on Arco Cast Iron Radiatoes (1959), then the PDF in red. This will give you a catalog of Arco rads supplied by my first employer McDonald heating Pittsburgh, Pa. The last page has correction factors for hot water temps. This may help.