Patent ID: 8539789

Claim:
A heating and cooling system comprising: an evaporator configured to vaporize a refrigerant to cool a first fluid stream; a compressor coupled to the evaporator and configured to compress the vaporized refrigerant; a condenser configured to condense the refrigerant compressed by the compressor to heat a second fluid stream; a heat exchanger configured to receive the refrigerant from the condenser, to selectively extract heat from or to add heat to the refrigerant, and to transfer the refrigerant to the evaporator; first control valving between the condenser and the heat exchanger, configured to regulate flow of the refrigerant from the condenser to the heat exchanger in a first mode of operation of the system; and second control valving between the condenser and the heat exchanger, configured to regulate flow of the refrigerant from the heat exchanger to the evaporator in a second mode of operation of the system.