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Sizing

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Tim_14
Tim_14 Member Posts: 23
in THE MAIN WALL
Do I size a hot water boiler to the connected load?

Exsample: the radiators come out to 168,000 btu.
Do I replace with a 250,000 in and 178,000 out?
Thanks
Tim

Comments

  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
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    With Hot Water...

    ...size the boiler to the heat loss of the structure. Sizing it to the radiation (as with steam) would almost certainly result in a terribly oversized boiler.

    For whatever reasons; added insulation, storm windows, change of fuel, change of lifestyle etc. hot water radiators are almost always ENORMOUSLY oversized. 2x - 3x oversized (assuming 170 degree average supply temp) is common.

    The good part of this is that the rads run at a MUCH lower temp. As the rad temp drops the proportion of radiant to convective heat increases. This reduces drafts and increases comfort.

  • Tim_14
    Tim_14 Member Posts: 23
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    Mike I bought the boiler all ready.
    If it is oversized how can I bail myself out
  • Tim_14
    Tim_14 Member Posts: 23
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    HELP
  • Unknown
    Unknown
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    sizing

    gas or oil??

    who's make boiler??

    what model??

  • frank_2
    frank_2 Member Posts: 6
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    too large?

    Some guys here may yell at me, but I've seen "Heating Engineers" from utility companies have a burner tube removed and plugged at the manifold. I'm guessing that if it's oil you could down-fire by using a smaller nozzle.
  • Bill Brobst
    Bill Brobst Member Posts: 4
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    Just use the finger rule. Its been a wile but it goes something like stand at the curb, hold hand arms length away and hold up fingers untill it covers the house. How ever many fingers you have up is how many section boiler you will need. Now, take that to your broker and loose it.
  • kevin
    kevin Member Posts: 420
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    \"Down firing\" ....i have tried

    to get info. on doing this for both gas and oil but no manufacturer has been willing to say OK. All i get is a lot of no's And don'ts. (and maybe w/ good reason)
    I would get the boiler back to the supply house. Even if it meant paying a restock fee...
  • Steve Miller
    Steve Miller Member Posts: 115
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    oversized boiler

    If we come across oversized boilers that are short cycling, which is what will happen if it's already oversized, is to add a buffer tank. It's a solution to undersized boilers as well, so you have plenty of BTU's on hand to get a jump start on a heating load. It also eliminates the need to use primary/secondary piping. We like buffer tanks and try to use them on all the condensing boilers we install. Just make sure you get one with large enough taps if you have a specific flow rate you need for the boiler. We've been using Raypac's, you can get them up to 2'' taps for your boiler connections.

    Steve M.
  • Tim_14
    Tim_14 Member Posts: 23
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    SOLUTIONS to Sizing

    Well,I must say, that since I have met Dan I have changed my ways What I desided to do was to return the boiler for the correct one no big deal. I can sleep better(when i have time)But thanks for all the imput.
    Tim Kosturko
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