a solar chimney is a black painted chimney that attatches to the side of a biulding, it must be taller than the building though. when the sun heats the chimney, the hot air rises drawing the cold air out from under the ground therefore ventialting the house and also cooling on hot days. to cool you can close the vents that the hot air escapes through and insert fans in the chimney and the hot air will be blown around the house.