US Patent 8113011 Apparatus for use as a heat pump

Apparatus (10′) for use as a heat pump comprising: compression chamber means (40′); inlet means (30′) for allowing gas to enter the compression chamber means; compression means (60′) for compressing gas contained in the compression chamber means; heat exchanger means for receiving thermal energy from gas compressed by the compression means; expansion chamber means (124′) for receiving gas after exposure to the heat exchange means; expansion means (120′) for expanding gas received in the expansion chamber means; and exhaust means (100′) for venting gas from the expansion chamber means after expansion thereof.