Abstract: A solid state heating and cooling apparatus for controlling the temperature of a room includes a plurality of series-coupled thermoelectric modules having first and second sides which become hot and cold, respectively, when current passes through said modules in a first direction and which become cold and hot, respectively, when current passes through in a second opposite direction. First and second heat sinks are placed proximate to the first and second sides to be either heated or cooled thereby. A first inlet duct having a fan therein cooperates with a first outlet duct so as to cause air to flow from the room whose temperature is to be controlled past the first heat sink and back into the room. A second inlet duct has a fan positioned therein so as to cause waste air to flow past the second heat sink and through a second outlet duct to an area apart from the room whose temperature is to be controlled.