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    Sizing new boiler (7 Posts)

  • bhinkle50 bhinkle50 @ 1:23 PM
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    Sizing new boiler

    First I wanted to say thank you for all the info you guys put out here. I've been lurking this forum for about a year learning as much as I can for what I hoped would be a boiler replacement this spring. Well, as they say "best laid plans". I don't think we're going to make it as the old boiler has started to leak and it seems to be getting worse.

    In reading this forum and a couple of Dan's books, I've learned that I have about 7 different problems that I plan to correct as a part of this replacement. The first step I am doing is measuring out the size of my boiler as I think it was oversized to what I need.

    I have a total of 16 radiators. 14 of them are American Radiators "Murray" fin style. I found an article on this site that shows the EDR for the various sizes (enclosure and radiator combined). The remaining 2 I have I can't find using the search. They are Trane fin style.

    I've attached a picture here is someone could help with the EDR info for these it would be great.

    They are 54" long and the enclosure itself is only 13" tall.
  • bhinkle50 bhinkle50 @ 1:43 PM
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    Currrent info

    The current boiler I have is WM EG75 that has a gross BTU rating of 300k and a net I=B=R rating of 180 MBH.

    So far, my EDR calculation is about 350 without these 2 radiators, so unless I'm doing something wrong it appears the current boiler is overrated by a decent margin.

    The Murray sizing I used was from this link:

    http://www.heatinghelp.com/files/articles/1273/55.pdf
  • ALIGA ALIGA @ 1:58 PM
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    U can probably get a eg45 or eg 50

    Or a Williamson. Which is a rebadged weil
  • kcopp kcopp @ 4:15 PM
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    what is the depth .....

    of the convector?
  • Steamhead Steamhead @ 4:25 PM
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    Maybe one of these?

    http://www.heatinghelp.com/files/articles/1280/218.pdf

    As our host would say, it pays to wander off the Wall.
    "Reducing our country's energy consumption, one system at a time"

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    Baltimore, MD (USA) and consulting anywhere.
  • bhinkle50 bhinkle50 @ 4:42 PM
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    Looks about right, but convector depth seems different

    The convector is 5 3/8" wide. I couldn't tell some of the dimensions in the pdf on that link, but it looked like the one that was closest was 6 1/16".

    These are also in a cabinet that is only 13" high, so I'll probably have to work up a custom number.

    Using the table in the doc for the enclosed 6 1/6 at 55", the 18" yields a 31.

    Do you think it's reasonable to estimate these radiators at 25 since the cabinets are only 13" and this convector isn't quite as wide?

    Thanks again for all the help.
  • Steamhead Steamhead @ 5:44 PM
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    In another reference

    the Hydronic Rating Handbook, a flat-top, 6" deep, 14" tall, 56" long Trane wall-hung convector has a rating of 46.5 square feet EDR. I could not find anything else that was close to your units, so this is the rating I would use.
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
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