A guide system including a top end, a bottom end, a lumen and a plurality of openings, the system is disposed within a coil lumen at the bottom end of the heat exchanger coil with the bottom end of the system extending beyond the bottom end of the coil in a direction from the top end to the bottom end of the coil, the system configured in a shape of the coil lumen and the openings are disposed on the bottom end of the system, wherein the heat exchanger is configured to channel the flue flow from a burner through a path to heat a fluid flow of the coil before entering the lumen of the system via the openings to avoid a pressure drop due to a tendency for the flue flow to follow a path defined by a shape of the bottom end of the coil.

Water heaters are disclosed having first and second fluid conduits, where the second fluid conduit is fluidly coupled to and disposed about at least a portion of the first conduit. One or more heating device, and preferably an infrared light source, can be disposed between the first and second conduits, such that water flowing within the conduits can be heated by the heating device.

A water heater insert device positioned within an electrical showerhead or as a standalone liquids heating device. The water heater insert optimizes heat transfer by channeling water through a channel of a spiral or zigzag form where a deployed heating element supplies thermal energy. The channel maximizes water contact while minimizing the space. A temperature limiter adds protection against scalding.

A fluid heater (10), for example, for machines for preparing beverages, includes: a heating core (12) including a first elongated heating element (121) and a second elongated heating element (122), which are co-extensive; and a conduit (14) with an inlet end (10a) for fluid to be heated and an outlet end (10b) for heated fluid. The conduit (14) is wound around the heating elements (121, 122) in a winding pattern including a set of first winding loops (141) wound around the first heating element (121) and a set of second winding loops (142) wound around the second heating element (122), the first winding loops (141) being interleaved with the second winding loops (142).

A heat exchanger, comprising at least a double shell, wherein the lower portion of the inner space of the inner shell is filled with liquid phase change medium, and at least one coiler is provided in the upper portion. The heated fluid flows in the coiler. After the downstream side pipe of the coiler is pierced through the inner shell, at least one surrounding pipe is formed in the cavity between the double shells. The bottom heat exchange plate of heat exchanger of the inner shell is located above the heat source. The cavity between the two shells forms the flue gas passage. After bottom heat exchange plate of the inner shell is heated by the heat source, the flue gas rises from the bottom of perimeter of the inner shell along the flue gas passage and the heat is transferred to the heated fluid in the surrounding pipe. The heat device using the heat exchanger according to the present invention can significantly improve the efficiency of heat utilization.

A sheath heater includes: a housing having an accommodating space formed therein; a plurality of main terminals electrically connected to an outside of the sheath heater through an electric circuit, wherein the accommodating space is filled with magnesia and the plurality of main terminals are disposed in the accommodating space to penetrate through one side and another side of the housing; an overheat preventing means located in the housing, connected in series with the electric circuit, and having a PTC element controlling a flow of current of the electric circuit according to a temperature of the PTC element; and a heating element electrically connected to the electric circuit and generating heat during the flow of current.

A volumetric heating device for beverage preparation machines, along with a beverage preparation machine containing same, are disclosed, along with methods of producing and using same.

The present invention relates to an electric water heater having an instantaneous hot water storage-type structure allowing a continuous outflow of a large amount of hot water instantaneously, without having to heat the water accommodated inside a housing directly. In the present invention, since the water flowed into the housing is heated while passing through the first and second heat exchange pipes, there is an effect that a large amount of hot water is instantaneously provided without having to heat a large amount of the water accommodated in the housing directly.

The invention relates to an electric heater, in particular auxiliary heating system, for a motor vehicle, comprising a volume (15) for receiving and conducting a liquid, in particular water, as well as a liquid inlet (13) and a liquid outlet (14) in such a manner that liquid can flow into the volume (15) via the liquid inlet (13) and can flow out via the liquid outlet (14), wherein at least one heating element (16), in particular a heating resistor, and a flow-conducting device (12) is disposed in the volume (15), wherein the flow-conducting device (12) comprises at least one flow-deflecting and/or turbulence-generating device (25) for deflecting the flow and/or for generating turbulence.

A fluid heater includes: a passage member having a passage formed therein; a heater for heating the passage member; a fixing member for fixing the passage member to a fluid control device; and a connection member connected to the passage member so as to allow fluid to flow into the passage member. The passage has a helical shape.