Geo Exchange Heating and Cooling System:

http://www.vredevoogd.com

  

http://www.nuenergygroup.com

 
Earth has a feature than can absorb the heat of sunlight and save it. The temperature of the underground is usually stable . These features of earth can be use in order to warm building in winter and cool it in summer .This system consisted of the pips which are located underground and filled with water, heat pipe inside the building and a system to scatter the heat or cool inside the building ( Florides,G 2007). As it can be seen in the pictures in winter  cool water from building will  be delivered to warmer underground to became warm and in summer warm water from building will be delivered to become cold and go back to the building. This system is efficient and use small amount of energy for heat pump. Therefore it can reduce the cost of cooling and warming of the building.
Source:
 http://www.sciencedirect.com/science/article/pii/S0960148107000092