I've had two months of electric and natural gas bills since the installation of two 2 ton Climate master Tranquilities, a packaged for the down stairs and indoor split servicing the second floor. The home is 2,6oo sf home built in early to mid 70's. As part of the geo project, I had quite a bit of insulation added in attic, in basement and air sealing of home envelop. With all the variables involved, i.e., additional insulation, different temperatures compared to last year and fluctuation in energy costs from previous year, trying to calculate actual dollar savings is like comparing apples to oranges to watermelons. But comparing the last two months' natural gas and electric bills to the last years bills, I'm figuring I'm heating my home for less than $100 per month. We do keep our down stairs thermostat at 69* and the upstairs thermostat at 67*. What I like the most is, the temperature at the thermostat never budges. As a result, my brain never has to recognize a differential in temperature swings so I never feel cold! And in fact, constant swings in temperature differentials is when you feel warm or cold. When there are no swings in temperature, you feel nothing... which is good. It makes it easier for me to keep home at 69 degrees. Over all, I'm very pleased at the operation costs of the units and their performance.