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sizing a hot water boiler

allan Member Posts: 1
I am looking to find out how I know what size forced hot water boiler I need to purchase to heat 2500 square foot area.
or 18700 cubic foot area.
any info is appreciated


  • Dan_16
    Dan_16 Member Posts: 11

    Measure the elements only and then add them up and multiply that # by 690. Thats your net.
  • Scooter Libby
    Scooter Libby Member Posts: 21

    You don't size a boiler by square feet or by radiation. You size a boiler by heat load. You'll have to use software that does heat load calculations.

    Think about it. How does square feet matter if you don't account for the weather in the area or the type of construction?

    There are a lot of incompetent hacks in this business who still use a formula like "50 BTU per sq ft", or who still size based on radiation. This leads to oversized boilers and higher gas bills.
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