Why do you doubt anyone has calculated the total cost of owning and operating such a system? I bought and paid for two heat pumps twelve years ago and the reduc

Why do you doubt anyone has calculated the total cost of owning and operating such a system? I bought and paid for two heat pumps twelve years ago and the reduction in energy costs resulted in them paying for themselves after 11 years. The cost of ownership was simply the purchase and installation cost as I did not take out a loan or receive any government funding. There was virtually no maintenance required except cleaning the humidity drain half a dozen times. Right now I'm waiting to see how long they last before they fail so I can calculate the total amount of savings. I should also point out that because my heat pumps are 12 years old, they only have a CoP of 3, while new heat pumps have a CoP of 4 and it is expected units with a CoP of 5 will be available within a few years.