A water heater can include a baffle and a slab heat exchanger with at least two rows of heat exchanger tubes, each row comprising a plurality of heat exchanger tubes. At least one of the heat exchanger tubes comprises a tube and a plurality of fins on the exterior of the tube circumscribing the tube, wherein the outer edge of each fin of the plurality of fins is bent at least at the same three areas of each fin such that the bends form at least three flat or concave areas running along the length of the heat exchanger tube.

A heat exchanger and a fin are provided. The heat exchanger includes: a fin. The fin includes a fin body and a flange, the fin body being provided with a heat exchange tube hole, the flange being provided on the fin body and surrounding the heat exchange tube hole; and a heat exchange tube passing through the heat exchange tube hole and connected to the flange. The flange includes a first sub-flange and a plurality of second sub-flanges, the first sub-flange is connected to the fin body, the plurality of second sub-flanges are connected to the first sub-flange and spaced apart from one another, and a height of the first sub-flange is less than a height of the second sub-flange.

A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus in which frost melt water is inhibited from reaching an upper surface of a header include: heat transfer tubes arranged in parallel with each other; a fin connected to one of the heat transfer tubes; and a header connected to the heat transfer tubes and having a header end surface along a direction in which the heat transfer tubes are arranged in parallel. The fin has an edge facing the header and extends in a first direction perpendicular to the axes of the heat transfer tubes. An end portion of the fin projects in the first direction relative to the header end surface, and another end portion of the fin in the first direction is positioned closer in the first direction to the heat transfer tubes than the header end surface is.

A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus in which frost melt water is inhibited from reaching an upper surface of a header include: heat transfer tubes arranged in parallel with each other; a fin connected to one of the heat transfer tubes; and a header connected to the heat transfer tubes and having a header end surface along a direction in which the heat transfer tubes are arranged in parallel. The fin has an edge facing the header and extends in a first direction perpendicular to the axes of the heat transfer tubes. An end portion of the fin projects in the first direction relative to the header end surface, and another end portion of the fin in the first direction is positioned closer in the first direction to the heat transfer tubes than the header end surface is.

Embodiments include various water heaters. In one example, a water heater includes a burner, an exhaust vent, a corrugated baffle having a first slit having a first length and a second slit having a second length that is less than the first length, and a heat exchanger. The heat exchanger includes a first set of heat exchanger tubes arranged in a first row, and a second set of heat exchanger tubes arranged in a second row, the second set of heat exchanger tubes having a third tube having a first angled surface and a second angled surface, where the first angled surface and the second angled surface together form a fin. The third tube can be arranged such that the fin is disposed at least partially between the first curved outer surface and the second curved outer surface.

Embodiments include various water heaters. In one example, a water heater includes a burner, an exhaust vent, a corrugated baffle having a first slit having a first length and a second slit having a second length that is less than the first length, and a heat exchanger. The heat exchanger includes a first set of heat exchanger tubes arranged in a first row, and a second set of heat exchanger tubes arranged in a second row, the second set of heat exchanger tubes having a third tube having a first angled surface and a second angled surface, where the first angled surface and the second angled surface together form a fin. The third tube can be arranged such that the fin is disposed at least partially between the first curved outer surface and the second curved outer surface.

A heat exchanger includes a plurality of flat heat transfer tubes each having a flat cross-sectional shape, a flat outer side surface, and an interior defining a passage through which a fluid flows, the plurality of flat heat transfer tubes being arranged with the flat outer side surfaces facing each other, and a plurality of corrugated fins each having a wavy shape, each of the plurality of corrugated fins being disposed between and joined to flat heat transfer tubes of the plurality of flat heat transfer tubes that are adjacent to each other. Each of the plurality of corrugated fins has portions that correspond to peaks of the wavy shape and have lower flexural rigidity than other portions of the corrugated fin.

A heat exchanger includes a plurality of flat heat transfer tubes each having a flat cross-sectional shape, a flat outer side surface, and an interior defining a passage through which a fluid flows, the plurality of flat heat transfer tubes being arranged with the flat outer side surfaces facing each other, and a plurality of corrugated fins each having a wavy shape, each of the plurality of corrugated fins being disposed between and joined to flat heat transfer tubes of the plurality of flat heat transfer tubes that are adjacent to each other. Each of the plurality of corrugated fins has portions that correspond to peaks of the wavy shape and have lower flexural rigidity than other portions of the corrugated fin.

According to certain embodiments, an adsorption heat exchanger (AdHEX) part is provided. The AdHEX part comprises a linear guiding element, and a plurality of planar structures that include fins. Each of the planar structures is: mounted on the linear guiding element via a joint element, the joint element configured to cooperate with the linear guiding element to form a slider joint, coated with an adsorbent coating, and fixed on the linear guiding element, at a respective position, by a fixing means that restricts linear sliding movement of each of the planar structures to form an arrangement of coated planar structures that are stacked along the linear guiding element.

A heat exchanger includes multiple tubes and multiple fins. Each of the tubes has a tubular shape extending in a horizontal direction. Each of the fins is disposed between adjacent ones of the tubes in a vertical direction vertical to the horizontal direction. Each of the fins is corrugated and includes bent portions located near the adjacent ones of the tubes and flat plate portions each of which extends in the vertical direction to connect between two of the bent portions. Each of the fins includes a pair of slits and an offset portion. At least a portion of the pair of slits extends to one of the bent portions. The offset portion is formed by having a portion of each of the fins between the pair of slits recessed inward of the one of the bent portions.