A heat transfer tube and a heat exchanger incorporating at least one heat transfer tube are provided. The heat transfer tube and the heat exchanger are optimized for use within an air conditioner (which is configured to operate only in a cooling mode). The heat transfer tube includes a tube body with an interior surface and an exterior surface. The tube body defining an outer diameter (D.sub.o) and a wall thickness (W.sub.T), wherein a ratio (W.sub.T/D.sub.o) the wall thickness (W.sub.T) to the outer diameter (D.sub.o) is between 0.061 and 0.071. The heat transfer tube includes multiple pluralities of adjacent helical fins protruding circumferentially around the interior surface of the tube body at respective helix angles. The multiple pluralities are separated by one or more transition area(s).

In a refrigeration system, a tube-and-fin heat exchanger has spaced fins that extend to an outer periphery of the heat exchanger and has smaller embedded fins in between or in a spaced relationship with each of the other fins. The embedded fins do not extend all the way to the outer periphery of the fins along the airside directions but have a shorter outer periphery such that there is an offset distance. Because of the offset distance, there is space that continues to provide room for fluid movement without fouling of the face of the heat exchanger and that provides an expected appearance while still having the benefit of additional fins elements further inside of the heat exchanger. Other exchangers and condensers are included.

A heat exchanger has an upper manifold with a first curved section; a lower manifold spaced from and extending parallel to the upper manifold and having a second curved section; a plurality of refrigerant tubes, and a plurality of corrugated fins. Each corrugated fin is formed by a strip having radiused portions alternating with planar portions, and the radiused portions are in contact with the respective adjacent refrigerant tubes. Each of the fins has a curve-inner edge and a curve outer edge and at least one edge of the curve-inner edge and the curve outer edge of at least one fin has a recessed portion in the planar portions that is recessed inward toward a center of the core.

A heat exchanger is provided and includes parting sheets flat along a first axis and curved along a second axis perpendicular to the first axis, a fin sheet interposed between the parting sheets and corrugated along the first axis to form fins that are curved along the second axis and diffusion bonds formed along an entire length of a fin to diffusion bond the entire length of the fin to the parting sheets.

A microchannel heat exchanger having: fin segments defined between lower and upper fin tips; at each fin tip, the fin segments have inner and outer facing surfaces; each fin segment having louvers having: an upper transition region at an upper louver end, adjacent an upper fin tip; a lower transition region at a lower louver end, adjacent a lower fin tip; and a straight region extending therebetween, wherein: the transition regions along the inner facing surface at each fin tip have a first transition surface having a first transition length, disposed at a first transition angle; the transition regions along the outer facing surface at each fin tip have a second transition surface having a second transition length, disposed at a second transition angle; wherein: the first transition length is longer than the second transition length; and/or the first transition angle is smaller than the second transition angle.

A composite server heat sink with a metal base having a thermal conductivity of at least 200W/mK. Plural fins extend from the metal base, each fin having an anisotropic thermal conductivity in a range of approximately 300 to 650 W/mK in a longitudinal direction of the fin and less than approximately 30 W/mK in a widthwise direction of the fin. Each fin includes graphite in an amount of approximately 45-70 wt. %, diamond in an amount of approximately 2.5 to 10 wt. % with the balance comprising a metal selected from one or more of copper and aluminum. To create the anisotropic thermal properties, the graphite is aligned along the longitudinal direction of the fin.

A heat exchanger includes a flat tube and a plurality of fins. The plurality of fins are arranged on the flat tube and inclined with respect to a longitudinal direction of a cross section perpendicular to an axis of the flat tube. The plurality of fins may be inclined at different angles with respect to the axis of the flat tube. The flat tube may include a straight portion on which the plurality of fins are arranged, and a bend on which at least one fin other than the plurality of fins is arranged. The at least one fin extends perpendicularly to the axis of the flat tube.

A process for manufacturing a cast metal heat exchanger housing (12) for a vehicle heater having a pot-shape housing wall (14) extending in a direction of a housing longitudinal axis (L) and having a plurality of heat transfer ribs (22) extending on an outer side of the housing wall (14) in the area of a circumferential wall (16) and in the area of a bottom wall (18) of the housing wall (14) in the direction of the housing longitudinal axis (L). The process includes metal casting wherein a sprue cross-sectional area including at least some of the heat transfer ribs (22). The cast metal heat exchanger housing has an axial end face formed upon cutting off metallic material that is essentially at right angles to the housing longitudinal axis and extends into an area of at least some of the heat transfer ribs.

A heat exchanger of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a plurality of microchannel tubes, where each microchannel tube of the plurality of microchannel tubes is configured to direct refrigerant therethrough, and a plurality of fin sets, where each fin set of the plurality of fin sets is disposed between corresponding adjacent microchannel tubes of the plurality of microchannel tubes. Additionally, each fin set of the plurality of fin sets includes a respective fin density based on a location of the respective fin set along a height of the heat exchanger.

A vapor chamber structure including a main vapor chamber, at least one heat dissipation structure, and a plurality of metal blocks is provided. The main vapor chamber includes an upper plate and a lower plate. The main vapor chamber further includes a first cavity formed between the upper plate and the lower plate. The heat dissipation structure is located on an outer surface of the upper plate and fluidly connected to the first cavity of the main vapor chamber. The metal blocks are disposed in the first cavity.