O K now that i have all your attention.
I am sorry to post this here but i did not know the right forum . I belong to several forums and i get a sense that this group [coal men] is ..mature , down to earth , intelligent , and will want to save money .
I have had an idea in my head for many years. I do not know how to work out the sizing , or "engineer" it , but i think it will work .
Take several hundred to several thousand feet of , say 1" flexible plastic tubing and bury it 10-12ft below the surface of the yard . Run it into the house to a circulator then to , say maybe a "modine style hanging radiator [the ones in garages , with the fans behind them]
GET IT ??
The ground at that level stays a constant 55 deg.
TELL ME WHAT YOU THINK [ before i start digging for nothing ???]