Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Pre 1935 Steam Wall Radiators

Chris Maderia
Chris Maderia Member Posts: 120
Can anyone out there help in figuring out how to calculate SqFt EDR for some old Wall Steam Radiators and turning them into btu. I have attached a picture of the type of radiator. It is firgure 21.

In Room 1 I have 4 on 2 walls that are 2'x 1' in a bank of 4 and 1 wall that has 1 2' x 1' in a bank of 10.

In Room 2 I have 2 that are 2'x 1' in a bank of 20.

Thanks in advance for any help you may give....


  • Steamhead
    Steamhead Member Posts: 16,899
    Each section of standard wall radiation

    whose measurements are probably closer to 21 x 13 inches, is rated at 7 square feet EDR. On steam, each square foot EDR gives off 240 BTU. On hot water the output will vary with the water temp, but with a boiler temp of 180 degrees F and a 20-degree delta-T, each square foot will emit 150 BTU.

    BTW, #24 is definitely pre-1935.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Looking Through \"EDR\"

    Can positively identify only one: #23 It is an American Rococo #7-A. Should measure 13 5/16" h x 21 7/8 l. EDR is 7 sq. ft.

    The Rococo was made in other sizes: 13 5/16" x 16 5/8" has 5 sf EDR; 29 1/16" x 13 5/16 has 9 sf EDR.

    Sizes were rather standardized so you should be able to compare #21 and #22 to the Rococo measurements. Looks like #22 is either 5 or 7 sf; #21 probably 14 but maybe 10 sf.

    #24 unlike anything in EDR. Looks like they tried to pack some "extra" radiation surface into a smaller area. By eye I'd say 5 or 6 sf.

    #20 looks like it could be a Lincoln Wall Radiator. If so, EDR is 3 sf per section (38"); 2½ sf per section (32"); 2 sf per section 26"; 1½ sf per section 20".

    You should be able to use the measurements for the Lincoln for #19 as well.
This discussion has been closed.