A heat exchanger includes a tube expansion portion formed by expanding a heat transfer tube so that an outer peripheral surface of the heat transfer tube is pressed against an inner peripheral surface of a hole provided in a side wall portion of a case. The tube expansion portion includes first and second bulge portions positioned respectively on the inside and the outside of the side wall portion so as to sandwich the side wall portion in an axial length direction of the heat transfer tube and configured such that respective outer peripheral surfaces thereof partially bulge outward in a radial direction of the heat transfer tube, an end portion tip end of the heat transfer tube is positioned apart from the second bulge portion, and the end portion tip end and a part in the vicinity thereof are expanded so as to be included in a part of the tube expansion portion. Thus, effects such as improving the precision with which the side wall portion of the case, the heat transfer tube, and a connecting tube are fitted to each other can be achieved, and as a result, the respective parts can be brazed easily and appropriately.

Electric fluid heater for a vehicle, including a heating block with an inlet and an outlet for the fluid, a first channel for the fluid intended to flow between the inlet and the outlet, a first tube and a second tube with opposing ends mounted in headers, the tubes having heating elements. The first channel is delimited by a top plate and a bottom plate sealingly connected to the first tube, the second tube and the headers.

A secondary heat exchanger includes a case and a first heat transfer tube portion. The case includes a box body and a first closing member. The box body is provided with a second opening on one side in a third direction. A first assembly in which the first heat transfer tube portion and the first closing member are assembled integrally is mounted to the box body so that a plurality of first heat transfer tubes are is inserted into the box body from the second opening and so that the second opening is closed by the first closing member.

A tankless hot water heater has a molded body having an inlet and an outlet. The water heater has a clamshell design such that upper and lower portions are removably attached to one another. A channel extends from the inlet to the outlet. Heating elements extend through at least a portion of the channel and are configured to heat water flowing through the channel. Sensors are configured to measure temperature of water flowing through the channel prior to coming into contact with the heating element. Sensors measure flow rates, temperatures, presence of air, and/or other factors. A controller adjusts power supplied to heating elements using data from sensors.

A heat exchanger includes a case, fins, and heat transfer tubes. Combustion exhaust gas passes downward in the case. The fins are disposed at a lower portion of the case and arranged in the first direction. Each of the fins includes a first end and a second end that is an opposite end from the first end in a second direction intersecting the first direction. Each of the fins includes through holes in which the heat transfer tubes are inserted. Each of the fins includes heat receiving portions arranged in the second direction and connecting portion connecting the heat receiving portions. The heat receiving portions include a first heat receiving portion disposed at the first end. The first heat receiving portion includes a first recessed portion recessed from an outer edge of an upper part of the first heat receiving portion.

A heating apparatus is disclosed. The heating apparatus comprises a PTC heating element, a first electrode, a second electrode, a first protection layer, a second protection layer, a first interlayer, and a second interlayer. A hardness of the first protection layer is greater than that of the first interlayer. A hardness of the second protection layer is greater than that of the second interlayer.

A water heating device includes: a heat exchanger having a case to which heating air is supplied, and heat transfer pipes accommodated inside the case; and a straightening vane arranged on the downstream side in a heating air flow direction of the heat transfer pipes, and having a plurality of vent holes. The heat transfer pipe includes a plurality of pipe body portions that extend along a direction intersecting the heating air flow direction and approach the straightening vane. The plurality of vent holes are arranged so as to overlap the plurality of pipe body portions in the heating air flow direction.

A heat exchanger including a gas inlet through which a combustion gas flows in and a gas outlet through which the combustion gas flows out is provided. The heat exchanger includes a housing in which the gas outlet is formed, a partition member, and a plurality of heat transfer tubes accommodated in the housing. The partition member is mounted in the housing so that there is a portion in which a flow area of the combustion gas is smaller than that of the gas inlet between the gas inlet and the gas outlet.

A heat exchanger (1) includes a heat exchanging body (20) disposed within an outer box (10). A supply pipe (21) and a discharge pipe (22) in fluid communication with the heat exchanging body (20) respectively extend through first and second insertion holes (31, 32) in the outer box (10). Elastic seal members (40; 240) are respectively provided around the supply pipe (21) and the discharge pipe (22) and between a first sidewall (11) of the outer box (10) and the heat exchanging body (20). At least one biasing member (50; 250) exerts a lateral biasing force (F1; F2) on the elastic seal members (40; 240), thereby maintaining the elastic seal members (40; 240) in a state of compressive deformation and contacting the outer box (10) and the heat exchanging body (20) in an air-tight manner to block potential leakage paths (LP1; LP2) via the insertion holes (31, 32).

An exhaust duct includes an upper duct being open at opposite ends thereof and a lower duct being open at a tip end thereof. One end of the upper duct is connected, inside an enclosure of a water-heating device, to an exhaust adaptor disposed on the enclosure, and an opposite end of the upper duct communicates with the tip end of the lower duct. The upper duct is connected to the lower duct so as to be slidable along a reference direction in which the lower duct extends from the tip end of the lower duct, and the upper duct is configured to be separated from the exhaust adaptor by sliding along the reference direction.