If you are thinking of a heating and cooling system for your new home, try to look at geothermal heating. Alliantenergygeothermal.com provides information on the science behind geothermal home systems including economic and environmental advantages. A recent study showed that geothermal heating saves up to 30% more compared to natural gas systems, the nearest best alternative. It also creates more energy (a range of 2.5 to 3.5 units) for every unit of energy used. Talk about efficiency!