Here are 2 possible configurations of homes using Geothermal heat transfer of Ammonia or Alcohol units. the first is a desing also utilizing a heat sink florring designed to passively circulate heat thorugh teh passages in cinder blocks. this design is from Lotus and Rocky Mountain Solar. http://RockyMtSolar.com. The second is a basic design showing tha the heat exhcnager will cool in summer and heat in winter using teh same heat differential of the roof and ground. (less info)