Patent ID: 6886355

Claim:
An air-conditioning system with a refrigerant medium circulating in a refrigerant loop, said system comprising: a variable-stroke compressor comprising a high-pressure outlet chamber, a drive chamber and an intake suction chamber; a first valve regulating a first flow of refrigerant medium from the high-pressure outlet chamber to the drive chamber; a second valve regulating a second flow of refrigerant medium from the drive chamber to the intake suction chamber; and a control unit; and an evaporator connected to said compressor in said refrigerant loop, wherein the variable stroke of the compressor is controlled by at least one of said first flow and said second flow, wherein said first and second valves are operable independently of each other under the control of the control unit, and wherein said circulation of refrigerant medium through said refrigerant loop can be minimized by simultaneously opening said first and second valves, whereby said evaporator is prevented from freezing over when no cooling power is drawn from the air-conditioning system.