Abstract: A housing cooperates with an air mover rotating about a rotation axis to move air received from an approach to an exhaust. The approach is generally oriented about a direction intersecting the housing at upstream and downstream limits. The housing presents an interior surface establishing radii between the axis and the surface. The radii have a generally constant radial value across a width in planes containing the axis in a first zone between the downstream limit and a first locus, and in a second zone between a second locus and the exhaust. The radii vary between a smallest and a largest radius across the width in planes containing the axis in a variance zone upstream of the axis. The smallest radius is less than the radial value at the first and second loci. The largest radius is larger than the radial value at one of the first and second loci.

Abstract: An aluminum heat exchanger is provided. In one embodiment, the aluminum heat exchanger comprises a fin having a first aperture therethrough with a flange formed around the first aperture. The fin is made from a first alloy having a first melting point. The heat exchanger includes a refrigerant tube made from a second alloy having a second melting point. The refrigerant tube extends through the first aperture. The heat exchanger also has a tubular coupling made from a third alloy having a third melting point and that is coupled to an end of the refrigerant tube. A fourth alloy having a fourth melting point less than the first, second, and third melting points is interposed the refrigerant tube and the flange, and further interposed the refrigerant tube and the tubular coupling. A method of manufacturing and a refrigeration unit are also provided.

Abstract: In accordance with the present invention, a method of determining refrigerant charge level in a space temperature conditioning system includes the steps of establishing a relationship between at least one selected system operating parameter and refrigerant charge level, independent of ambient temperature conditions; measuring the selected parameter(s) while the system is in operation; and using the established relationship and the measured parameter(s) to determine the refrigerant charge level. In one embodiment of the invention, both condenser subcooling and evaporator superheat parameters are measured and the predetermined relationship between charge level and each of these parameters is used to determine the actual refrigerant charge level.

Abstract: An evaporator for evaporating a phase change refrigerant in a space conditioning system such as an air conditioner, heat pump or refrigeration system, is provided. The evaporator includes an inlet for introducing the refrigerant into the evaporator, an outlet for discharging the refrigerant from the evaporator and plural conduits defining a plurality of hydraulic flow paths between the inlet and the outlet. In accordance with the invention, a separator is provided to substantially separate liquid refrigerant from vapor refrigerant before the refrigerant is introduced into the evaporator to enhance refrigerant distribution within the evaporator, thereby improving evaporator performance.

Abstract: An evaporator for evaporating a phase change refrigerant in a space conditioning system, such as an air conditioner, heat pump or refrigeration system, is provided. The evaporator includes an inlet for introducing the refrigerant into the evaporator, an outlet for discharging the refrigerant from the evaporator and plural conduits defining a plurality of hydraulic flow paths between the inlet and the outlet. In accordance with the invention, a separator is provided to substantially separate liquid refrigerant from vapor refrigerant before the refrigerant is introduced into the evaporator to enhance refrigerant distribution within the evaporator, thereby improving evaporator performance.