Measure Heat Load Instead of Calculating it?
I have tried several free software packages to calculate the heat load of my 3,100 sq ft home near Boulder Colorado. The numbers from the software (and websites) all vary a lot. So I started thinking why not measure the actual load?
My design heating temperature is 0°F for my area. My gas furnace is 98.7% efficient.
This coming winter when our temperature will drop to 0°F for at least a few hours during the night why not measure the therms used during those hours to keep my house warm and then subtract the 1.3% because my furnace is not 100% efficient?
For instance if the temp is a 0°F outside between the hours of 1AM – 3AM (no solar heat gain) and I measure 1.5 therms during those hours:
1.5 therms X .987 = 1.4805 therms (Furnace efficiency)
1.4805 is 148,014.659 BTU
148,014.6 BTU / 2 hours = 74,007 BTU Heat Load
Does that seem right?
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