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EDR calculation for old existing boiler, way oversized??

I used this link to figure out the numbers for my existing system:
http://www.smithfieldsupply.com/company_info/forms/radiatorest.pdf

Something seems off...
11 radiators of varying types:
40 sq ft hallway
50 sq ft big kitchen
34 sq ft small sitting room
34 sq ft kid bedroom 1
37 sq ft kid bedroom 2
27 sq ft 2nd floor full bath
34 sq ft upstairs office
16 sq ft small 1/2 bath
24 sq ft living room A
24 sq ft living room B
34 sq ft small 1st floor bed

... This totals around 354 sq ft.

*1.25 factor= ~442 sq ft (under the impression that the extra 25% is allowance for piping loss, etc)

My existing american standard is 713 sq ft (~45+ year old).... I've found one floor hole in the kitchen where there was probably a radiator but that's it, even a large one would add another 50 sq ft.

Did they size boilers huge back in the day? When this sucker runs it eats oil.

I'm starting to do research on boiler replacement for when oil starts to creep up in price. Got the wood stove cranking so I can keep the heat up to a comfortable level during the day.

Comments

  • Abracadabra
    Abracadabra Member Posts: 1,948
    You don't need to add the 1.25 factor. It's already included in the rating of the boiler. If your calculatation are correct you need a boiler around 354 sq.ft. steam. Your boiler is 100% oversized.

    The best thing you can do is check for air infiltration around doors/windows/etc to reduce fuel consumption. After that consider improving your insulation.
  • BobC
    BobC Member Posts: 5,491
    That boiler was probably installed when oil was less than 15 cents a gallon (That's what it was in 1970 when I got out of the army). There were two sizes to choose from - too big and much too big.

    I agree the best thing you can do is find and eliminate any air infiltration; then beef up the insulation. When the time comes find someone who understands steam and put in a properly piped Megasteam.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    John Mills_5
  • SteamingPile
    SteamingPile Member Posts: 14

    You don't need to add the 1.25 factor. It's already included in the rating of the boiler. If your calculatation are correct you need a boiler around 354 sq.ft. steam. Your boiler is 100% oversized.

    The best thing you can do is check for air infiltration around doors/windows/etc to reduce fuel consumption. After that consider improving your insulation.

    Thanks guys.

    Wow 100% oversized. That's insane. Not only that but it's my only hot water source so its burning oil constantly.

    I'm not sure how to find out the year since American Standard sold off their division I guess right around 1970 (?). I figure its ~1970
    at the latest.

    This house is older, 1880-ish but does have some fiberglass wall insulation from when the previous-previous owners did drywall.
    It's new to me so I'm not sure if its throughout.

    Every window in the place was replaced with double pane low E vinyl so at least the windows are sealed well. I've been hunting drafts for a week now and have got most of them I think.