Abstract: Disclosed herein are a variable capacity rotary compressor and a refrigerant cycle system having the variable capacity rotary compressor. The compressor includes a cooling unit and a pressure reducing unit to reduce temperature and pressure of a bypassed refrigerant, thus allowing the bypassed refrigerant to have the same temperature and pressure as when entering a cylinder at first. The compressor includes the cylinder in which a refrigerant is compressed. An inlet pipe delivers the refrigerant into the cylinder. An outlet pipe delivers the refrigerant out of the cylinder. A bypass hole is provided at a predetermined position of the cylinder to bypass the refrigerant from the cylinder, thus varying a compression capacity. A bypass pipe connects the bypass hole to the inlet pipe to allow the refrigerant bypassed through the bypass hole to enter the cylinder. The cooling unit cools the refrigerant flowing through the bypass pipe.

Abstract: An air conditioner including a compressor compressing a refrigerant to produce a high temperature gaseous refrigerant, a hot water producing device producing hot water by performing a heat exchanging process whereby heat is transferred from the high temperature refrigerant fed from the compressor to water, an outdoor heat exchanger performing a heat exchanging process whereby heat is transferred between the refrigerant and outside air, and a hot/cold water producing device producing hot water by performing a heat exchanging process whereby heat is transferred from the refrigerant fed from the hot water producing device to water, or producing cold water by performing a heat exchanging process whereby heat is transferred from water to the refrigerant fed from the outdoor heat exchanger.