I don't think I will ever know the answer to this question ever here is my scenario:
1. Last winter was our first winter in the house, only the second floor was heated for the most part (the downstairs was under renovations). We kept the upstairs at 55 during the day, 62 when home and 58 at night, a little warmer when we had guest. Wife was not a happy camper
, we had a bed warmer that helped out.
2. We kept the first floor at 50 just to keep the pipes from freezing
3. Used $1200 in Natural gas from Nov-March (5 months lets say) with these conservative thermostat numbers
In March I had the idea to get a coal burner to reduce some cost (Wife agreed).
Now the downstairs is completed (still have a 50 year old forced hot air unit), and a 96% unit upstairs.
I estimate that if I kept the house to normal temps 70-72 that $1200 number would be at least triple based on my friends comparable house numbers, because I now have to heat both floors. So if I am conservative and use the $3600 comparable number we will cut that in a third using our Vermont Castings stove while having a comfortable house and happy wife
. Please provide your thoughts.