Patent ID: 7938634

Claim:
A self-modulating scroll compressor comprising: a first scroll member having a first base and a first generally spiral wrap extending from the first base; a second scroll member having a second base and a second generally spiral wrap extending from the second base, the first wrap of the first scroll member and the second wrap of the second scroll member interfitting to define compression chambers, the second scroll member being driven to orbit relative to the first scroll member to compress a refrigerant entrapped in the compression chambers during a compression cycle, wherein the compression chambers define a first volume at a beginning of the compression cycle and a second volume at the end of the compression cycle; the self modulating scroll compressor operating at least at a higher capacity and a lower capacity, wherein a ratio of the first volume to the second volume defines a built-in volume ratio at the higher capacity that is modified to optimize overall compressor efficiency; the built-in volume ratio decreasing to an effective volume ratio at the lower capacity operation; and the built-in volume ratio being modified to be at least 2.4.