The performance of a compressor using the back-pressure control system discussed here is much better than that of a conventional compressor, especially under the cooling half-load condition at a low speed and compression ratio. Nearly optimum performance is obtained under all operating conditions by keeping the back pressure at a level that is a constant amount above the suction pressure. This reduces friction at the sliding portion between the orbiting and fixed scrolls, and eliminating the back-pressure holes decreases the compression loss due to the "breathing action." This back-pressure control system greatly improves the annual performance (reduces annual energy consumption) of household air conditioners.

Units: SI