The invention relates to a heat exchanger, in particular an water-air heat exchanger or oil-water heat exchanger, comprising at least one first fluid channel for guiding a first fluid, and at least one second fluid channel for guiding a second fluid, the at least one first fluid channel being joined to a fluid receiving volume, in particular on the outlet side, said fluid receiving volume being equipped with an electric heating coating (13).

Methods and systems for water heater system receiving electrical power from an electrical grid. The system includes an electronic processor configured to monitor an average water temperature of the water within a water tank of the system based on a first and second signal from an upper and lower temperature sensor, operate an upper heating element heating an upper portion of the tank and a lower heating element heating a lower portion of the tank in a first operation mode, receiving, via a transceiver, either an add load command or a shed load command from a grid controller, operating the upper heating element and lower heating element in a second mode in response to receiving the add load command, and operating the upper heating element and lower heating element in a third mode in response to receiving the shed load command.

The present invention is directed to an integrated boiler system, comprising: two separate boilers, one disposed inside the other, each of the boilers having: (a) a vertical partition disposed therein; (b) a water passage at a top side of the partition; and (c) a water passage at a bottom side of the partition; a chamber disposed in, or generated by, a gap between the boilers; and a heating element, disposed in the chamber, for heating the boilers simultaneously by the same energy.

A variable heatable radiator for use in a fluid circuit containing coolant therein, and which can generate substantial amounts of heat to heat larger spaces, such as in a home or business, while utilizing minimal power to run, and which can be utilized in various implementations and configurations. The radiator can be selectively activated or de-activated by, for example, a cell phone or the like whereby the fluid circuit in the radiator can be monitored for time of use, temperature and cost of use. The circuit possesses at least one opening defined therein on sides of the radiator and top and bottom thereof which is in communication with the circuit, whereby a heating element can be inserted to heat the fluid.

A heating unit for heating fluid is described having at least one electrical resistance heating element on an outer surface of a tube. At least one indexed groove is provided around a surface of the tube allowing for at least one retention clip to hold the electrical resistance heating element. A heating chamber is also provided to enclose a portion of the tube and to provide a flow channel therebetween. The heating chamber includes an optical sensor to detect overheating of the at least one electrical resistance heating element. Fluid is heated by flowing over the surface of the at least one electrical resistance heating element and through the tube.

The invention relates to an oil-water heat exchanger, in particular for connection to an internal combustion engine of a motor vehicle, comprising at least one electric heating coating (13) which is applied to an outer side and/or in the interior of the heat exchanger.

A water heater that includes a cylindrical storage tank and at least one heating element, is modeled using a one-dimensional model that includes: a vertical stack of disks representing the water volume in the cylindrical storage tank, and a stack of annular segments surrounding the vertical stack of disks. Various temperature measurements are determined via resistance calculations of the at least one heating element. The stack of annular segments represents the cylindrical wall of the cylindrical storage tank. The one-dimensional model may be used by a condition-based maintenance system comprising an electronic data processing device configured to detect a failure mode present in the water heater based on an output of the water heating model component. Some illustrative failure modes include insulation disturbance, heating element failure, excessive sediment buildup, or a drip tube rupture.

A water heater is provided that heats water in a storage tank and discharges the heated water. The water heater includes a storage tank configured to store water, at least one first temperature sensor configured to sense a temperature of the water stored in the storage tank, a second temperature sensor configured to sense a temperature related to an outside of the water heater, a first heat exchanger comprising at least one heating element configured to heat the water, a second heat exchanger comprising a heat pump system and configured to heat the water, and a controller configured to control at least one of the first heat exchanger and the second heat exchanger based on a temperature sensed by the second temperature sensor and a set water temperature.

A tube heater for heating a fluid in an interior of the tube has a stainless steel cylindrical core. The core ranges about 3 to 300 mm in length and about 100 to 200 microns in thickness with an outer diameter of about 8 to 20 mm. An inner surface of the core has dimples and a conductive coating. A patterned resistive layer overlies the core in a thickness of about 9 to 15 microns. The resistive layer is thin- or thick-film printed about a circumference of the core. Two glass layers surround the resistive layer. Each glass layer is electrically insulative. The glass underlying the resistive layer has a thermal conductivity of more than 2 W/mK while the glass overlying the resistive layer has a thermal conductivity of less than or equal to 0.5 W/mK.

A tube heater for heating a fluid in an interior of the tube has a stainless steel cylindrical core. The core ranges about 3 to 300 mm in length and about 100 to 200 microns in thickness with an outer diameter of about 8 to 20 mm. An inner surface of the core has dimples and a conductive coating. A patterned resistive layer overlies the core in a thickness of about 9 to 15 microns. The resistive layer is thin- or thick-film printed about a circumference of the core. Two glass layers surround the resistive layer. Each glass layer is electrically insulative. The glass underlying the resistive layer has a thermal conductivity of more than 2 W/mK while the glass overlying the resistive layer has a thermal conductivity of less than or equal to 0.5 W/mK.