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Basement Ceiling Radiator - Sq Ft?

Single pipe steam, house built in 1926, needs new boiler so I'm trying to size for it. Rest of house is regular tube standing units, so I just used the chart. I'm at 434.7 so far. Didn't yet allow for a couple that have been removed, the never-ever used one in the garage (groan!) and this basement ceiling radiator.

I'm going to assume it was an add-on since there is a hole gouged out of the plastered basement ceiling for it's vent. It is 28" high, and consists of four sections put together side-by-side such that it is only one section deep. I couldn't reach to measure, son tells me it's 3.5." I should have measured length of entire thing, but did not as plastic grate cover was in the way.

Each of its side-by-side sections consists of 6 tubes-- two fatter ones on each end and four thinner ones in the center.

Anyone ever seen one of these, or have any guidance on how to measure it's sq ft?

Also vent appears badly rusted on. Normally I would not use PB Blaster on a steam radiator vent, but should this one be the exception?


  • Jamie Hall
    Jamie Hall Member Posts: 22,885

    that you don't find such a critter in one of Dan's handy dandy compilations, remember that "EDR" stands for "Equivalent Direct Radiation" and it's an area.

    To a very close approximation, you can get a usable value by determining the surface area of the thing.  And, to a very close approximation, that is going to be the surface area of all the skinny tubes (their circumference times their total length, converted to square feet) plus the surface area of all the fat tubes (ditto).  If you want to be fussy, add in the headers the same way.  Is it exact?  No.  Is it going to be close enough?  Yes unless you are a real fanatic about things.

    Why not use PB Blaster on a radiator vent?  Not down the vent hole, of course, but just around the thread where it screws in.  That is, assuming you have a good reason to want to get the vent off -- but I would check first and see if it's working.  If it's working, leave it be.  Don't fix it if it ain't broke.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Steamhead
    Steamhead Member Posts: 16,714
    That's a standard wall radiator

    where each section looks like 29x13 inches. 9 square feet per section. 
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Overwhelmed_2
    Overwhelmed_2 Member Posts: 18
    Thanks! Onward to Pickup Factor!

    Thanks, both of you! That brings me to 470.7 sq ft. Now, onward to my Pickup Factor thread ...

    I'll get this new boiler ordered yet!

    Then I'll have to figure out how to deal with the current (cracked) boiler's THREE connections to the main.That's how it appears to me at the moment. Clearly I have more to learn-- or this heating system was designed by an extremely crazy person.