The present invention provides a boiler system, for example for use in heating a domestic hot water supply, and which is significantly more fuel efficient than existing boilers, the boiler system comprising a first reservoir and a second reservoir which together defme a combustion enclosure, a storage tank positioned to defme an upper wall or roof of the enclosure and being in fluid communication with the first water reservoir, a heat exchange tube located in the storage tank and being in fluid communication with the second water reservoir; and a burner arranged to directly heat atmospheric gases within the enclosure in order to indirectly heat the walls of the enclosure.

A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EM radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.

A gas water heater includes a bottom housing having an opening, a burner mounted at the bottom housing, and a cover plate assembly mounted at the bottom housing and covering the opening. The cover plate assembly includes a first cover plate and a second cover plate. The second cover plate is located between the burner and the first cover plate. The cover plate assembly has an air inlet channel located between the first cover plate and the second cover plate. The first cover plate has a first flow inlet in communication with the air inlet channel. The second cover plate has a second flow inlet distant from the first flow inlet, and in communication with the air inlet channel and an air inlet of the burner.

A gas water heater includes a bottom housing having an opening, a burner mounted at the bottom housing, and a cover plate assembly mounted at the bottom housing and covering the opening. The cover plate assembly includes a first cover plate and a second cover plate. The second cover plate is located between the burner and the first cover plate. The cover plate assembly has an air inlet channel located between the first cover plate and the second cover plate. The first cover plate has a first flow inlet in communication with the air inlet channel. The second cover plate has a second flow inlet distant from the first flow inlet, and in communication with the air inlet channel and an air inlet of the burner.

A combined heating system comprising a first heating subsystem including a first fluid conductor, a first heating unit adapted to heat a first fluid and output the first fluid at the outlet of the first fluid conductor, and a fluid mover adapted to move the first fluid through the first heating unit, a second heating subsystem including a second fluid conductor adapted to receive a second fluid, a third fluid conductor, a second heating unit adapted to heat the second fluid and output the heated second fluid in the third fluid conductor, a fluid mover adapted to move the second fluid from the outlet of the third fluid conductor to the inlet of the second fluid conductor, at least one heat exchanger operably connected to a downstream location of the first heating unit and a fourth fluid conductor connecting the second fluid conductor and the third fluid conductor.

A jacket for a hot water heater appliance includes a top, bottom, front, back, and a fastener. The top is configured to insulate an upper portion of a hot water tank. The bottom is configured to insulate a lower portion of the hot water tank. The front is configured to insulate a front portion of the hot water tank. The back is configured to insulate a back portion of the hot water tank. The fastener is configured to releaseably fasten the front to the back. The top, bottom, front and back include expanded polypropylene (EPP) configured to provide insulation to the hot water tank.

A jacket for a hot water heater appliance includes a top, bottom, front, back, and a fastener. The top is configured to insulate an upper portion of a hot water tank. The bottom is configured to insulate a lower portion of the hot water tank. The front is configured to insulate a front portion of the hot water tank. The back is configured to insulate a back portion of the hot water tank. The fastener is configured to releaseably fasten the front to the back. The top, bottom, front and back include expanded polypropylene (EPP) configured to provide insulation to the hot water tank.

A storage medium stores a control program including program code for, in the case of increasing a quantity of combustion in the boiler group, after a high-efficiency combustion shift signal that makes the shift to the high-efficiency combustion position is output to all of the boilers subject to high-efficiency control by which control is conducted on the basis of combustion at the high-efficiency combustion position, outputting a control signal that makes the shift to a higher combustion position than the high-efficiency combustion positions for any one of the high-efficiency control subject boilers.

A diffuser is provided for use in a thermal storage tank. The diffuser includes a fluid inlet to receive a flow of liquid into the diffuser, and a fluid outlet to discharge the flow of liquid out of the diffuser into an internal volume of the thermal storage tank. A flow circuit extends between the fluid inlet and the fluid outlet. A plurality of flow sections are sequentially arranged along the flow circuit. Each one of the plurality of flow sections defines a cross-sectional flow area for the flow of liquid. The cross-sectional flow area within any one of the plurality of flow sections is greater than the cross-sectional flow area within any of the plurality of flow sections arranged upstream of said one of the plurality of flow sections.

A diffuser is provided for use in a thermal storage tank. The diffuser includes a fluid inlet to receive a flow of liquid into the diffuser, and a fluid outlet to discharge the flow of liquid out of the diffuser into an internal volume of the thermal storage tank. A flow circuit extends between the fluid inlet and the fluid outlet. A plurality of flow sections are sequentially arranged along the flow circuit. Each one of the plurality of flow sections defines a cross-sectional flow area for the flow of liquid. The cross-sectional flow area within any one of the plurality of flow sections is greater than the cross-sectional flow area within any of the plurality of flow sections arranged upstream of said one of the plurality of flow sections.