A storage boiler, a tank of which has a first chamber for housing a given quantity of water; an inlet for feeding water into the first chamber; an outlet for discharging water from the tank; and a first resistor fitted inside the first chamber to heat the water inside the first chamber to, and keep it at, a standby first temperature; the first chamber housing a tubular body, which houses a second chamber communicating with the first chamber and with the outlet, and housing a second resistor selectively activatable to heat the water flowing through the second chamber to a dispensing second temperature higher than the first temperature.

A plasma heating apparatus including a boiler vessel for holding water to be heated, a cathode housed in the vessel, the cathode defining a watertight cathode chamber isolated from the water in the vessel, and, an anode housed in the cathode chamber, the anode including an internal passage for receiving a gas from outside of the vessel when the passage is connected to a gas supply, and wherein the anode is connectable to a power source for receiving power for generating a plasma in the cathode chamber. In another aspect, the present disclosure relates to a heat or power generating system or plant including the plasma heating apparatus.

This invention relates primarily to an electric heater based tankless water heater, though some aspects may also apply to a natural gas or other fuel based tankless water heater. In particular aspects relating to smart communication and coordination of the tankless water heater with other devices, which may be electrically powered or powered by other fuels, may also apply to non-electric flow through fluid heating systems. The subject tankless water heater invention incorporates several aspects relating to energy and construction efficiency which will be detailed further. These include both physical aspects, such as coatings, tubing and heater element design, and electrical aspects, such as power control for individual heater elements, which can make the tankless water heater more compact and more efficient in operation, with reduced instantaneous and long term load on electrical supply systems.

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.

The present invention provides an electric boiler having a heating element surrounded by a thermally conductive inner container to define an inner passage about the heating element, the inner container having an inlet and an outlet for a flow of water and is arranged such as to cause water received at the inner container inlet to flow along the inner passage in close proximity to a surface of the heating element, the boiler further comprising an outer container in which the inner container is substantially located, the outer container defining an outer passage about at least part of the inner container, the outer container having an outlet into the inner container wherein the outer container is arranged such as to cause water to flow along the outer passage in close proximity to a surface of the inner container, such that water received in the boiler makes at least a double pass through the boiler to increase the potential heat transfer to the water.