Abstract: A heat exchanger (10) including a heat exchanger conduit and fins arranged on the conduit tubes (12, 12') to further heat transfer between the external fluid flowing over the fins (22, 22') and the fluid flowing within the conduit. The fins (22, 22') include a row of apertures through which tubes (12, 12') of the heat exchanger conduit extend. The leading (4, 6) and trailing (48) edges of the fins (22, 22') are contoured to substantially conform to isotherms around the circulating fluid flowing within the tubes (12, 12'). To achieve this edge configuration while also allowing for a dense packing of fins and tubes in a multi-row heat exchanger, the leading and trailing edges are wave-shaped such that adjacent fins can interfit together.

Abstract: A heat exchanger including a heat exchanger conduit and fins arranged on the conduit tubes to further heat transfer between the external fluid flowing over the fins and the fluid flowing within the conduit. The fins include a row of apertures through which tubes of the heat exchanger conduit extend. The leading and trailing edges of the fins are contoured to substantially conform to isotherms around the circulating fluid flowing within the tubes. To achieve this edge configuration while also allowing for a dense packing of fins and tubes in a multi-row heat exchanger, the leading and trailing edges are wave shaped such that adjacent fins can interfit together. Suitable wave shapes include a sinusoidal wave as well as a trapezoidal wave. The isothermally contoured leading and trailing edges result in a fin configuration which efficiently utilizes the materials of its construction as well as results in minimal wastage during construction with a minimal impact on heat transfer.

Abstract: The present invention involves split system air conditioners. Specifically, the present invention provides a condenser unit with cross-flow blowers. A single cross-flow blower may be used to draw air through a heat exchanger and expel the air adjacent to a cut-off portion. Further, dual cross-flow blowers may be provided to enhance the performance of the condenser unit. The combination of air streams from two cross-flow blowers provide better air circulation through the heat exchangers and a more uniform exhaust stream. The condenser unit is more compact and can be mounted on the wall, on the overhang, or on the top of the building. These various mounting locations take advantage of the air boundary layer near the building and thus the air conditioning system operates more efficiently.

Abstract: A method and a tool for expanding the outside diameter and forming grooves on the inside surface of a tube. The tool comprises an axially extending mandrel, a centering portion, and a grooving portion. The centering and grooving portions of the tool are both secured to the mandrel, with the grooving portion located axially rearward of the centering portion. The centering portion radially projects outward of the mandrel, and the grooving portion is coaxial with and radially projects outward of the central portion of the tool. The central portion defines a smooth annular surface to engage and partially expand the tubes, inside and outside diameters, to guide the tube onto the grooving portion, and to maintain the grooving portion centered within the tube. The grooving portion defines an outside surface to expand the tube further, and preferably includes a plurality of external fins to form grooves on the inside surface of the tube.