Heating Calculator

[Paul Bailey]

Here is a free heating calculator that includes a column for ground source numbers. You can adjust the Efficiencies and cost accordingly based on fuel prices in your area. Paul:)

[Rob Beckers]

Thanks for the calculator Paul!
Just entered in the numbers for an open-loop water-source heat pump vs. my current high-efficiency gas furnace; the savings in case of switching to a heat-pump are not quite as large as I was hoping for. Goes to show that your spreadsheet is a useful tool! Derating the heat-pump efficiency for the water pump losses as reported by Mel takes quite a bite out of potential savings.

For those that want to use your calculator, be careful when entering electricity and natural gas prices. Officially the electricity rate here is 5.0 cents per kWh. However, when looking at my use vs. what I paid for, the actual cost turns out to be 13.1 cents per kWh, thanks to a "debt retirement charge" (due to the cost of nuclear power plants if I understand this right), "adjusted usage" (due to line losses), and of course taxes. Quite a difference. For natural gas the same is true.

-RoB-

[Paul Bailey]

Hi Rob: How much of a derating factor did you see Versus what you had expected??? Now even with a closed loop ground source I think the pump runs the whole heating season... and then of course for the cooling season. Lets face it Mels' report is the best Real world report I've seen by someone willing to remain objective and share the numbers good or bad....Paul:) Thanks again Mel.

[Rob Beckers]

Paul, according to Mel's measurements the open-loop water-source heat pump he's using comes in at 482% efficiency by itself (so 1kWh of electricity netts you 4.82kWh of heat). The energy needed to pump the water makes the overall efficiency 348%. A derating of 28%.

Mel, what's the listed COP for the Geomax2 heat-pump that you are using?

-RoB-