What is Stirling? or, The Stirling Cycle
The Stirling cycle can be applied as a heat engine cycle in which heat is accepted at a high temperature, rejected at a lower temperature, and net work or power is produced. Or the cycle can be applied as a refrigeration/heat pump cycle in which net work is done on the Stirling device and, heat is accepted at a low temperature and rejected at a higher temperature; if the useful heat is that which is accepted at the low temperature, then the device is being used as a refrigeration or cooling device; if the useful heat is that which is being rejected at the higher temperature, then the cycle is being used as a heating device.