Upgrading an old oil furnace and AC unit to a new high efficiency heat pump has been one of the two keys to making my family’s home in PA produce more energy than it consumes (the other of course was adding a big fat solar array). Now that we’ve lived in the house for over a year I thought it would be a good time to look back at the data and see what sort of return on investment (ROI) this heat pump has given us.

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