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ken_6 Member Posts: 33
why do indirects seem to be rated as first hr gal vs conventional tank type are recovery per hr?


  • Bigger numbers.

    It makes them look MUCH bigger. The problem lies in the fact that there really is no industry consensus or standard for rating water heating appliances. It should be first hour, and then each hour thereafter, along with some sort of seasonal efficiency factor.

    I'll just stand over here in the corner holding my breath waiting for consensus, OKay... (I look pretty good in dark blue, don't I)

    If you don't want to turn blue, you could do the analysis on a one to one basis yourself.

    Assume that 80% of the tanks storage volume can be poured out without significant dillution. Add to that the gallons per hour of 100 degree rise output based on combustion efficiency and you have the first hour draw.

    For each hour thereafter, it's strictly based on combustion efficiency.

    I wrote an article about this at www.contractormag.com, specifically,


    Hopefully that will answer your questions. If not, come on back and we can discuss it further.

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