Standby Loss for Commercial-Grade Boiler or Water Heater

Modified on Thu, 24 Apr at 4:37 PM

If standby loss is not available in Btu/hr, convert using this equation: 


Btu/hr = Standby Loss [%] x Tank Size [Gallon] x 8.33 x (Hot Water Set Point [°F] - Ambient Temperature [°F] ) / 100


Example (Note: Sample Values Used): 1% x 120 Gallon x 8.33 x (135°F - 67.5°F) / 100 = 674.73 Btu/hr Standby Loss 


You may also use the below Commercial DHW Standby Loss Calculator Spreadsheet.

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