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Boiler sizing question

Charlie_7
Charlie_7 Member Posts: 2
in THE MAIN WALL
Have a forced hot water baseboard system heat with a house heat loss of 77,000 and want to install 50 gal. indirect on boiler... not sure what Input or net output I should be looking for. Need help

Comments

  • DaveGateway
    DaveGateway Member Posts: 568
    Indirect specs should answer your question

    Many indirect install manuals will have a sizing chart telling what boiler BTU output is recommended for a given hot water load. In general your heat load is less then what most indirects of that size will require. 100K+ will give you reasonable recovery times. You could go smaller, but expect longer waits between showers. Look for some priority controls so you don't wind up oversizing the boiler too much to try to support both heating and hot water at the same time.
  • Ted_9
    Ted_9 Member Posts: 1,718


    Well Charlie what I would do is take your 77,000 heat loss and add about 20% to that. Brings you to a 92,400 BTU boiler. Check you indirect chart and you may find a 100,000 btu boiler would work great.

    And the reason I add 20% is because you did a heat loss at a temp say 5 degrees F. If its colder than that then the boiler will not be able to heat the house. And certainly use domestic hot water priority controls.

    Patriot Heating & Cooling, Inc.
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