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Flue Temp Computations

Mark_46 Member Posts: 312
Heat Transfer, Munchkin 80


  • Mark_46
    Mark_46 Member Posts: 312

    Hi all,

    Is there a standard method for finding boiler efficiency using flue temp measurements? Should the temp be compared to return water temp? Should one value be divied by another?

    I recently measured the following. This is a modulating/condensing boiler type. Is below enough data?

    Boiler set point/supply water temp = 123

    Boiler return water temp = 111

    Flue gas temp = 119
  • Todd_43
    Todd_43 Member Posts: 1

    With a modcon, efficiency is directly linked to the return water temp AND the partial load percentage. The manufacturer should have a graph showing you this. What brand are you using?
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