The present invention provides an outdoor water heater (10) having a lower chamber (12) located in a cabinet (14) which substantially sealingly encloses a naturally aspirated or natural draught burner 16, a combustion chamber, a heat exchanger (18), a flue (20) for conveying combustion gases from the burner (16), the flue (20) extending away from the heat exchanger (18) and passing through a middle chamber (22) located above the lower chamber (12), the flue (20) not opening into the middle chamber (22) and opening into an upper chamber (24) which has two opposed openings (24.2, 24.3), the upper chamber (24) and middle chamber (22) being substantially sealed with respect to each other to prevent combustion gas flow between the middle chamber (22) and the upper chamber (24), and wherein the middle chamber (22) has divider formations (22.1, 22.2) separating one side of the middle chamber (22) from an opposed side of the middle chamber (22), whereby the divider formations (22.1, 22.2) direct air flowing from one side of the middle chamber (22) to pass downwardly into the lower chamber (12) on one side then upwardly out of the lower chamber (12) to exit the middle chamber (22) on the other or opposite side.

A heating apparatus comprising a tank having a tank inlet, a tank outlet, a heat exchanger inlet and heat exchanger outlet. A heat exchanger is located in the tank and comprises a hollow body having a mouth coupled to the heat exchanger inlet and a flue outlet coupled to the heat exchanger outlet. A burner device has a burner head that is located at least partly located in the mouth inside said hollow body.

A condensation exchanger for heating of water and for production of sanitary water, providing a first inner coil with plain surface, and a second outer coil, said second coil being externally spirally wound with respect to said first coil, within said coils circulating a thermal carrier fluid, said first coil exchanging heat with combustion fumes by radiation and convection, and said second coil exchanging heat with the combustion fumes by condensation, wherein said second coil has a plain surface, and in that an insulating septum is provided, said septum dividing said exchanger in a first upper or combustion zone, and a second lower zone, said insulating septum dividing said exchanger in said two areas with a ratio of:
45%?H.sub.1L?60%.

A high efficiency condensing flue gas-fired water heater is provided with a secondary tubular flue mounted inside the water tank and secured thereto by dielectric connectors to electrically isolate the secondary tubular flue from the tank. The secondary tubular flue has an intermediate helical section and opposed connecting end sections which each form a part of the dielectric connectors. The connectors do not require any welding for its installation to the tank and a compression nut and dielectric insulators provide for a leak proof and electrically isolated connection. The method of securing the secondary tubular flue is also described.

A heat exchanger assembly includes a combustion assembly having a combustion chamber, a first heat exchanger, a flue gas passage having a condensation chamber, and a second heat exchanger. The first heat exchanger is located in the combustion chamber. The flue gas passage is configured to receive flue gas from the combustion chamber and to discharge the flue gas out of the heat exchanger assembly. The second heat exchanger is disposed in the condensation chamber and is configured to exchange heat with the flue gas entering the flue gas passage.

The present invention relates to a heat exchanger pipe enabling heat exchange between fluid flowing through the pipe and fluid existing outside the pipe, and a method of manufacturing the heat exchanger pipe. In particular, the present invention relates to a heat exchanger pipe that improves a heat exchange rate by making flow of fluid through the pipe more active and increasing a contact amount, that has an improved contact characteristic and a sealing characteristic between an outer pipe and an insert inserted in the outer pipe in the process of manufacturing, and that is easily manufactured; and a method of manufacturing the heat exchanger pipe.

A heat exchanger tube of a heating boiler, comprising an outer tube, which may be flown through by exhaust gases from the boiler firing and which may be surrounded by boiler water on the outside, and a profiled insert inserted into the outer tube, which comprises ribs running in longitudinal direction of the outer tube to enlarge the inner surface of the outer tube and which is in thermally conductive contact with the outer tube, are to achieve that an even greater heat transfer capacity from the combustion gases to the boiler water in the heating boiler is enabled. A first longitudinal section of the outer tube is formed in a cylindrical, smooth-walled manner and a second longitudinal section of the outer tube has at least one cross-sectional narrowing element narrowing the flow cross section. The profiled insert extends exclusively over the first longitudinal section of the outer tube.

A fin-and-tube type heat exchanger includes: a plurality of plate fins arranged in a case side by side in a fore-and-aft direction of the case; and a heat transfer tube including a plurality of straight-type tubular bodies each passing through these plurality of plate fins. First and second plate fins arranged side by side in the right-and-left width direction of the case are provided as a plurality of plate fins. The heat transfer tube has a connection tubular body connecting the straight-type tubular bodies passing through the first and second plate fins. The heat transfer tube passes through areas in which the first and second plate fins are arranged.

A motor/damper assembly installable on the top end of a fuel-fired water heater includes a support plate structure upon which a flue collar with a pivotally supported flue damper, a drive motor, and a drive shaft interconnecting the motor damper are mounted. The assembly is installed by placing the collar over the upper end of the water heater flue, securing the support plate structure to the top end of the water heater, and positioning a top cover housing on the support plate structure. Using the assembly provides improved support rigidity and alignment for the motor and shaft relative to the damper, improved repeatable precise manufacturing placement of the motor and shaft, improved construction aesthetics, with the cover also protecting the shaft from shipping and handling damages.

A system to reduce standby losses in a hot water heater is presented. The system utilizes a dual safety relay valve between the combination gas controller and the burner. The dual safety relay valve bypasses gas to a rotary damper actuator valve to position a damper flapper valve located over/inside the flue pipe. Once the flapper valve has opened to ensure combustion, the gas is allowed to flow back to the dual safety relay valve. Some of the bypass gas may be diverted to boost the pilot or to supply a booster. The dual safety relay valve is then opened to allow the gas supply to the burner. Once the burner is turned off, bypass gas bleeds out of the rotary damper actuator valve to close the damper flapper valve to reduce standby losses through the flue pipe, and to allow the dual safety relay valve to close tightly.