Provided is a gas furnace including a primary heat exchanger and a secondary heat exchanger through which a combustion gas produced by the combustion of a fuel gas flows. The gas furnace includes: a coupling box serving as an intermediary to connect the primary heat exchanger and the secondary heat exchanger; a collect box connected to the secondary heat exchanger, for letting in the combustion gas passed through the secondary heat exchanger; an inducer connected to the collect box, for inducing a flow of the combustion gas; and a bypass pipe connected to one side of the coupling box and including a bypass pipe for guiding the combustion gas passed through the primary heat exchanger to a hot water supply tank for supplying hot water to an indoor space.

A blower assembly is attached to a water heater having an exhaust opening, the assembly includes a tank cap attached to a tank of the heater. A recess surface formed in the exterior surface of the cap. A member has a first surface that is connected to the tank cap to form a cover plenum between the cap and the member. The blower includes a motor, an air moving member connected to the motor and a blower housing having an interior containing the fan. The blower housing has an input opening that communicates the blower housing interior with the member output opening. The blower housing, the member and the tank cap provide an exhaust gas flow path from the exhaust opening of the heater through the cover plenum, through the blower housing interior and out the output opening.

A water heater appliance for a recreational vehicle includes a tank and a flue disposed within the tank. The flue forms a U-shape that extends to and from an external side of the tank. A gas supply is in fluid communication with the flue. A burner assembly is disposed at an inlet of the flue. A baffle disposed within the flue. The baffle includes a plurality of restrictors configured to the baffle and the flue, and a flue collar mounted to the flue. The flue collar is configured to secure the baffle to the flue.

A fryer includes a fryer vat and a heating system with at least one heat exchange tube a burner end, an opposite end, and an internal passage from the burner end to the opposite end. A baffle is located within the internal passage for enhancing heat transfer from combustion gases to the heat exchange tube. The baffle has an axial length from a burner facing end to a discharge facing end. The baffle includes a plurality baffle panels that are interconnected and sequentially arranged along the axial length, with each baffle panel extending at least partially across the internal passage of the heat exchange tube. At least one baffle panel includes multiple sets of interconnected openings, wherein the openings of each set are interconnected with each other by one or more panel through slits so as to facilitate thermal expansion.

A coil assembly for a combustion chamber includes a first tube arranged into a plurality of inner coils and a second tube arranged into a plurality of outer coils that surround the plurality of inner coils. Each inner coil contacts adjacent inner coils. The plurality of outer coils are separated from adjacent outer coils by a plurality of spaces. The first and second tubes are configured to transport a heat transfer fluid (HTF). The plurality of inner coils are separated from the plurality of outer coils by a gap. The coil assembly also includes a cylindrical shroud surrounding at least a portion of the coil assembly. The cylindrical shroud has a length that is less than a length of the coil assembly.

A baffle arrangement disposed within the exhaust flue of a fuel-burning water heater promotes heat transfer from exhausted combustion by-products to the water storage chamber. The baffle arrangement has an elongate planar base and plural exhaust-directing fins spaced along opposite sides of the base. Each fin is a planar body extending perpendicularly from the base at an acute upward angle from a longitudinal centerline to a respective side of the base. The fins deflect combustion by-products laterally outwardly within the flue to promote heat transfer. The fins are of selected configurations generally increasing in surface area upwardly along the planar base for selectively controlling pressure drop within the exhaust flue. Hanger tabs project outwardly from the upper end of the base to suspend the baffle arrangement within the flue. The planar base, hanger tabs and exhaust-directing fins are formed integrally from a unitary body of sheet metal.

A structure of the heat exchange pipe is provided for conducting heat generated by combustion inside a burner to the outside. The structure of the heat exchange pipe includes a receptacle and an insertion. The insertion is disposed in the receptacle. The insertion includes at least three petals, each of which includes a first circular arc section and a second circular arc section. The first circular arc section extends toward a center of the receptacle and has a first arc angle. The second circular arc section has a second arc angle. The second arc section is arranged between two first circular arc sections of two adjacent ones of the petals. The first and second circular arc sections define a flue. As such, the insertion forms a flue baffle device.

A blower assembly is attached to a water heater having an exhaust opening, the assembly includes a tank cap attached to a tank of the heater. A recess surface formed in the exterior surface of the cap. A member has a first surface that is connected to the tank cap to form a cover plenum between the cap and the member. The blower includes a motor, an air moving member connected to the motor and a blower housing having an interior containing the fan. The blower housing has an input opening that communicates the blower housing interior with the member output opening. The blower housing, the member and the tank cap provide an exhaust gas flow path from the exhaust opening of the heater through the cover plenum, through the blower housing interior and out the output opening.

A gaseous fuel-air-flue gas burner is described herein. One device includes a housing having a combustion chamber containing a combustion area in which a combination of fuel, air, and flue gas mix to form a flame, a flame arrester having an outer surface for the flame to form, a supply chamber configured to receive the fuel, air, and flue gas mixture at an inlet and provide the combustion area with the fuel, air, and flue gas mixture at an outlet to produce a flame and a quantity of return flue gas, and a return cavity configured to move return flue gas away from the combustion area and into the inlet of the supply chamber.

A water heater appliance for a recreational vehicle includes a tank and a flue disposed within the tank. The flue forms a U-shape that extends to and from an external side of the tank. A gas supply is in fluid communication with the flue. A burner assembly is disposed at an inlet of the flue. A baffle disposed within the flue. The baffle includes a plurality of restrictors configured to the baffle and the flue, and a flue collar mounted to the flue. The flue collar is configured to secure the baffle to the flue.