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DHW Sizing

Gooz Member Posts: 7
Does anyone know where I could find good reference material to size domestic hot water loads for 1 or 2 family homes.  I'm interested in replacing the atmospheric hot water boiler with a condensing boiler and an indirect hot water tank.  Thanks!


  • Ironman
    Ironman Member Posts: 7,379

    Look at the DHW sizing tables in the attached. Usually, the smallest indirect is sufficient for an average home and family and will have more output than a 40 - 50 gal. gas heater.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Greg Maxwell
    Greg Maxwell Member Posts: 212
    Domestic Water

    The average DHW load - no whirlpools, is 15-20% on top of your heat load. With whirlpools, the load stays the same, but you have to size the tank for the dump load.
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