Abstract: A coil system for an outdoor heat exchanger in a HVAC system. The coil system comprises an integrated subcooler coil section positioned between the primary coil section and the expansion valve. A distributor combines the individual refrigerant streams from the coils of the primary coil section into a single refrigerant stream before separating the stream among the different coils of the subcooler section. The subcooler coil section is positioned such that the incoming air stream is directed directly at the subcooler coil section to maximize the difference in temperature between the air stream and the refrigerant within the subcooler section.

Abstract: A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. A cooling system provides direct, two-phase cooling of the rotor by combining gas refrigerant from the evaporator section with liquid refrigerant from the condenser section to affect a liquid/vapor refrigerant mixture. Cooling of the stator with liquid refrigerant may be provided by a similar technique. A noise suppression system is provided by injecting liquid refrigerant spray at points between the impeller and the condenser section. The liquid refrigerant may be sourced from high pressure liquid refrigerant from the condenser section.