Abstract: Liquid refrigerant interacts with the stream of gas flowing through in a centrifugal water chiller, downstream of the occurrence of the compression process in the compressor portion of the chiller but prior to the condensing of the gas in the chiller condenser, to reduce the acoustic energy of the gas. The noise emanating from the chiller which would otherwise result from the interaction of the discharge gas with the piping connecting the compressor portion of the chiller to the system condenser and/or with the components of the system condenser itself is thereby reduced without significantly affecting chiller performance or efficiency.

Abstract: A refrigeration system is disclosed which includes evaporator means of the type for producing chilled liquid and wherein a compressor of the centrifugal type is provided for compressing refrigerant which has been vaporized in the evaporator means. Both air cooled and liquid cooled condenser means are connected in parallel flow relationship to the compressor, whereby the heat of condensation and compression may be rejected either to a source of ambient air or recovered through heat exchange with a source of liquid, whereby a heated liquid is produced for use as desired.

Abstract: An air cooled centrifugal liquid chiller is disclosed which includes an air cooled condenser exposed to ambient conditions such that, during those times when the temperature of the ambient is at a relatively low level and the chiller is inoperative, refrigerant will tend to migrate to and condense in the air cooled condenser. If this accumulated condensed refrigerant is permitted to then flow by gravity to the evaporator of the chiller, the heat exchange liquid within the tubes thereof may freeze, causing possible damage. In order to prevent this occurrence, the conduit means connecting the air cooled condenser to the evaporator are provided with a trap portion disposed at a level above the maximum level of condensed refrigerant accumulation within the air cooled condenser, which trap portion is vented to a point in the air cooled condenser above said maximum level.