Abstract: A heating and cooling system includes an evaporator, a compressor, and a condenser. A heat exchanger, which may be an outdoor heat exchanger, is 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, disposed between the condenser and the heat exchanger, is configured to regulate flow of the refrigerant from the condenser to the heat exchanger in a first mode of operation. Second control valving, disposed between the condenser and the heat exchanger, is configured to regulate flow of the refrigerant from the heat exchanger to the evaporator in a second mode of operation. The system may be operated in a variety of modes by appropriate control of the valving and other system components.

Abstract: A noise control method is provided for a cooling system having at least one refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, at least one condenser fan, and an evaporator. Noise control is only performed periodically in response to requirements for reduced operation at predetermined times. The request for reduced noise triggers the commencement of the noise control method. The noise control method involves reducing the operating speed of the compressor, as well as reducing the operating speed of at least one condenser fan, to within a predetermined range of allowable reduced operating speeds. The noise control method temporarily overrides the ability of the cooling system to fully respond to increased cooling or heating demands.