In the beginning of this year, I blogged about the air-to-water
which is taking care that all the programmers in my office have it warm in winter.
It is now running for more than one full year, so I have some more data to show: The graph below shows the temperature and the needed electricity. It also contains the electricity needed by the full building, but at least 80% is used for the heat pump:
Easily to see that if it gets cold outside, the needed power goes up quite a lot. It looks maybe a bit scary, but interestingly, this system now is 50% cheaper than the old oil based heating: Our electricity bill is now only half of what we paid yearly for oil.
I'm quite impressed by that, I thought it would be cheaper with a heat-pump, but not by that amount. Nice to see that we will have it still warm inside, while paying less AND keeping the environment clean - our electricity is generated by water power.