A method of forming a cast heat exchanger plate includes forming at least one hot core plate defining internal features of a one piece heat exchanger plate and at least one first set of interlocking features. At least one cold core plate is formed defining external features of the heat exchanger plate and at least one second set of interlocking features. A core assembly is assembled where each hot core plate is directly interlocked to at least one cold core plate. A wax pattern is formed with the core assembly with an external shell formed over the wax pattern. The wax pattern is removed to form a space between the core assembly and the external shell. The space is filled with a molten material. Once the molten material has solidified, the external shell and the core are removed.

A water heater according to the present invention includes: a heating unit that includes a burner provided to cause a combustion reaction from air and fuel, and that is provided to generate heated water by using heat generated by the combustion reaction; and a humidifier unit that generates water steam by evaporating water using a combustion gas generated by the combustion reaction and discharged from the heating unit, and provides the water steam together with the air to the burner.

A method of forming a cast heat exchanger plate includes forming at least one hot core plate defining internal features of a one piece heat exchanger plate and at least one first set of interlocking features. At least one cold core plate is formed defining external features of the heat exchanger plate and at least one second set of interlocking features. A core assembly is assembled wherein each hot core plate is directly interlocked to the at least one cold core plate. A wax pattern is formed with the core assembly. An external shell is formed over the wax pattern. The wax pattern is removed to form a space between the core assembly and the external shell. The space is filled with a molten material and cures the molten material. The external shell is removed. The core assembly is removed. A core assembly for a cast heat exchanger is also disclosed.

A heat exchanger includes: flat pipes each including a passage for refrigerant that are arranged side by side in a predetermined step direction; and a header collecting pipe extending along the predetermined step direction that is connected to the flat pipes. The header collecting pipe includes: a flat pipe-side header forming member; and an opposite-side header forming member facing the flat pipe-side header forming member. The flat pipes are inserted in the flat pipe-side header forming member and an internal space exists between the flat pipe-side header forming member and the opposite-side header forming member. When viewed along the predetermined step direction: the flat pipe-side header forming member has a flat pipe-side curved portion protruding toward the flat pipes and the opposite-side header forming member has an opposite-side curved portion protruding toward a side away from the flat pipes.

A heat exchanger and an air conditioner are provided. The heat exchanger includes fins and flat pipes arranged in parallel. Each of the flat pipes includes a first finned region, a second finned region, and a finless region. The first finned region is the second finned region via the finless region. The fins are provided both between adjacent two first finned regions and adjacent two second finned regions. An end of the finless region connected to the first finned region is twisted and defined as a first torsion section, the other end of the finless region connected to the second finned region is twisted and defined as a second torsion section.

A heat exchanger includes a first channel with at least one first wall for porting a first fluid and a second channel with at least one second wall for porting a second fluid. The heat exchanger includes a barrier chamber located between the at least one first wall and the at least one second wall such that a rupture of one of the at least one first wall and the at least one second wall does not result in mixing of the first fluid and the second fluid. The heat exchanger includes a support member that extends between the at least one first wall and the at least one second wall.

A compact heat recovery unit which includes separate and distinct thermal cores housed in their own channels. Each thermal core and its respective channel is moved at intervals. When a thermal core and its channel is inserted into a high temperature fluid flow, the thermal core absorbs the heat. When this heated thermal core and its channel is then later inserted into a low temperature fluid flow, the low temperature fluid is preheated by the heated thermal core. This operation is repeated with at least two independent thermal cores and their respective channels to maintain substantially continual pre-heating of received low temperature fluid. Similarly, the compact heat recovery unit can be used in a cooling application where pre-cooling of received higher temperature fluid is executed.

A chilling unit includes: air heat exchangers each including heat transfer tubes and fins; and a machine room unit on which the air heat exchangers are provided. The air heat exchangers each have a long-side portion that extends in a longitudinal direction of the machine room unit. The air heat exchangers includes a pair of air heat exchangers that are inclined such that a spacing between upper end portions of the heat exchangers is greater than a spacing between lower end portions thereof. In each pair, the long-side portion of at least one air heat exchanger has a heat-exchanger end portion located at a unit end portion of the machine room unit in the longitudinal direction, and from the heat-exchanger end portion, heat transfer tubes that protrudes from an outermost one of the fins in an arrangement direction thereof and that extend linearly in the lateral direction do not extend.

In a heat exchanger installed on an intake path or exhaust path of an internal combustion engine and configured to cool gas by transferring heat between the gas containing exhaust and refrigerant, a water-repellent portion is formed at part of a portion that contacts the gas in a gas path through which the gas flows, and a hydrophilic portion is formed at another part of the portion. The water-repellent portion is a portion provided with water-repellent treatment. The hydrophilic portion is a portion provided with hydrophilic treatment. The hydrophilic portion is formed at a part having a temperature lower than the temperature of the part at which the water-repellent portion is formed while the heat exchanger is actuated.

A web for a rotary heat exchanger is configured for transfer of thermal energy and/or moisture to and/or from a fluid. The web includes first profiled sections and second profiled sections configured to protrude in opposite directions, each a fluid passage. The first and second profiled sections form a plurality of fluid flow channels, each fluid flow channel having a main fluid flow axis and being configured to allow fluid flow at least partially along the main fluid flow axis. Each fluid flow channel is formed by alternating at least one first profiled section and at least one second profiled section along the main fluid flow axis and by aligning the fluid passages of the alternatingly arranged first profiled section(s) and second profiled section(s). Each fluid flow channel has at least one lateral opening allowing fluid flow to at least partially travel between adjacent fluid flow channels.