Variable volume ratio screw compressor

A refrigerant circuit, comprising:

• a screw compressor, a condenser, an expansion device, and an evaporator fluidly connected, wherein the screw compressor includes:
• a suction inlet that receives a working fluid to be compressed;
• a compression mechanism fluidly connected to the suction inlet that compresses the working fluid, the compression mechanism including one or more rotors;
• a rotor housing, the one or more rotors disposed in the rotor housing;
• a discharge outlet fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism;
• and
• a valve assembly including a rotor sealing member moveable relative to the rotor housing between a first position and a second position to modify a suction port of the compression mechanism based on a discharge pressure of the screw compressor, and the second position disposing the rotor sealing member one or more of closer to a discharge end of the rotor housing than the first position or closer to the one or more rotors than the first position, wherein
• the rotor sealing member is spaced apart in a longitudinal direction from the discharge end of the rotor housing in both the first position and the second position, the longitudinal direction being parallel to a longitudinal axis of the compression mechanism, and
• a longitudinal length along which the compression mechanism compresses the working fluid is longer in the second position is longer than a longitudinal length along which the compression mechanism compresses the working fluid in the first position.