Patent ID: 8381538

Claim:
A heat pump refrigerant system comprising: a compressor assembly including at least two stages of compression connected in series, with a lower compression stage compressing refrigerant from a suction pressure to an intermediate pressure and passing this refrigerant to a higher compression stage compressing refrigerant from an intermediate pressure to a discharge pressure and with an intercooler positioned intermediate of said lower and higher compression stages; a switch operable to route refrigerant from said higher compression stage to an outdoor heat exchanger in a cooling mode of operation, and from said higher compression stage to an indoor heat exchanger in a heating mode of operation; an expansion device positioned intermediate of said indoor and outdoor heat exchangers; and a secondary fluid moving device for moving a secondary fluid over said outdoor heat exchanger, said intercooler being positioned such that it is in the path of the secondary fluid driven by said secondary fluid moving device, with the secondary fluid being moved over the outdoor heat exchanger and the intercooler in both the holing mode and the cooling mode.