Have you been reading the 'Why Dig' posts?
http://ecorenovator.org/forum/geothe...html#post11196
There is some discussion about using gas..
At night or on cloudy mild days, when it's in the 35-68 deg F range, this Sanyo can keep
the house at a nice warm 72 F for peanuts. It could very well be cheaper than gas..
I have a friend up the street who installed a cooling-only min-split.
He is kicking himself for not spending an extra $200 to add heat.
He's using oil heat, like 90% of the people in this area.
It's now over $3 a gallon..
That's a nice looking heater. Not too costly either..
I like the sound of your design.. If I wasn't so old, I would love to start over again
in a house that was insulated to my specs..