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 method of controlling water heater pilot flame ignition includes receiving, by a controller of a water heater, a user input and controlling a pilot gas valve to start a gas flow to a pilot burner in response to the user input. The method further includes, in response to the user input, controlling, by the controller, an igniter to generate an ignition spark for lighting a pilot flame. The method also includes controlling, by the controller, the pilot gas valve to maintain the gas flow to the pilot burner if the pilot flame is lit.

A hot water supply system decouples an intelligent hot water storage system from a water heating engine system. The water heating engine system includes a plurality of instantaneous water heaters that provide for redundant operation for improved reliability. The intelligent hot water storage system includes a storage tank that encloses a volume for storage of water. The intelligent hot water storage system includes a recirculation loop driven by an integrated pump and operated by an integrated controller. By positioning the tank recirculation outlet and inlet farther apart from each other, additional usable volume of hot water is provided by the intelligent hot water storage system. Isolation valves positioned on the input and output of a recirculation pump in the recirculation loop facilitate repair or replacement of the recirculation pump. The hot water system provides for increased capacity while providing redundant heating engines in a smaller floor space than conventional systems.

A combined heat and power system generates energy and efficiently captures a percentage of such energy that would otherwise be lost to, among other things, control the temperature and humidity of a house or dwelling.

An oil boiler includes an outer container having openings at opposite ends, a combustion chamber that covers an opening at an upper end of the outer container and in which a combustion reaction occurs, a lower cover that covers an opening at a lower end of the outer container, a plurality of flue tubes to heat heating water flowing in the outer container by guiding combustion gas, a burner including a fuel nozzle that sprays fuel, an air nozzle that injects air, and a spark plug that ignites a mixture of the fuel and the air, and a flame tube part that defines a tube space by surrounding a partial space in which the mixture is ignited, the flame tube part including a flame tube having an open lower end and a recirculation hole formed through the flame tube such that the combustion gas is introduced into the flame tube.

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 water heater appliance includes a tank storing water, a first temperature sensor, a second temperature sensor, and a heat source. A method of operating the water heater appliance includes determining a temperature set point of the water within the tank; obtaining a first temperature of the water within the tank via the first temperature sensor; obtaining a second temperature of the water within the tank via the second temperature sensor; determining a heat depletion level of the water indicating a temperature reduction of the water within the tank based on the temperature set point, the first temperature, and the second temperature; and activating the heat source based on the determined heat depletion level.

A heating assembly for heating a liquid storage tank includes a heat exchanger tank supported in one wall of the storage tank to extend into the storage tank in contact with liquid stored therein. The heat exchanger tank contains a heat exchanger fluid therein which is heated by a burner tube extending through the heat exchanger tank whereby heat is only transferred to the liquid in the storage tank through the heat exchanger fluid. A controller actuates the burner head of the burner tube to maintain temperature of the heat exchanger fluid between upper and lower temperature limits. The operation of the burner head is interrupted in response to temperature of the liquid in the storage tank exceeding an upper limit, or fluid level in the heat exchanger tank being below a lower limit as determined by respective sensors.

A portable hot water supply tank is adapted to be used with a heat source, and includes a water storage unit, a heat exchange unit, and a circulation unit. The water storage unit includes a base member defining a lower water chamber. The heat exchange unit includes a heat exchanger connected to the base member. The circulation unit includes an inlet pipe and an outlet pipe. The heat exchanger is movable relative to the base member between an unfolded position and a folded position. When the heat exchanger is at the first position, water stored in the lower water chamber is drawn into the inlet pipe, flows through the heat exchanger to be heated by the heat source, and eventually flows back to the lower water chamber via the outlet pipe.

A hot water supply system decouples an intelligent hot water storage system from a water heating engine system. The water heating engine system includes a plurality of instantaneous water heaters that provide for redundant operation for improved reliability. The intelligent hot water storage system includes a storage tank that encloses a volume for storage of water. The intelligent hot water storage system includes a recirculation loop driven by an integrated pump and operated by an integrated controller. By positioning the tank recirculation outlet and inlet farther apart from each other, additional usable volume of hot water is provided by the intelligent hot water storage system. Isolation valves positioned on the input and output of a recirculation pump in the recirculation loop facilitate repair or replacement of the recirculation pump. The hot water system provides for increased capacity while providing redundant heating engines in a smaller floor space than conventional systems.