A heating system including a thermal battery including an opening, a storage container configured to hold a first fluid therein, the opening configured to expose the first fluid to atmospheric pressure; and a fluid conductor disposed through the first fluid from an inlet point at the storage container to an outlet point at the storage container, the fluid conductor configured to receive a second fluid at a first temperature at the inlet point and to supply the second fluid at a second temperature higher than the first temperature.

A water holding tank for electric water heaters is described and particularly an improvement to the bottom end construction of the tank to prevent bacteria proliferation and the elimination of the cavitated circumferential area where sediments deposit to form a culture bed for bacteria to proliferate. Instead of modifying the shape of the bottom wall the improvement is a simple solution in that a filler material is set in at least a lowermost portion, and preferably a major portion, of the cavitated circumferential area to isolate that area from the interior of the water holding tank and form smooth flat surface areas which are planar to cause sediments to disperse and not form beds for bacteria to proliferate.

A device and water system for preventing the proliferation of living beings in the water pipes of buildings and that can be applied to taps with a supply of hot and cold water to improve the health standards of public and private constructions with hot water circulation systems, or without, by recirculation within the hot, warm or cold water system. The same permits the prevention of the freezing of the piping. The device has a bypass between the hot and cold water pipes that supply a tap, with a pump that causes recirculation of the water via the bypass, a mechanism for regulating the flow of water located in the bypass, a temperature probe in the water pipe above the bypass, a mechanism for activating and deactivating the pump, and a system for controlling the flow regulation mechanism, the activation and deactivation of the pump and functioning of the pump.

A method may measure a respective temperature at a respective remote location or at the respective water pipe with the respective temperature sensor. A method may determine from the respective temperature measured by the respective temperature sensor a water usage event at the respective remote location. A method may determine during a determined water usage event a temperature profile from the temperature measured by the respective temperature sensor. A method may determine from the temperature profile determined during the water usage event a risk factor of microbiological growth at the respective remote location or of microbiological growth within the respective water pipe. A method may execute a disinfection cycle for the respective remote location or the respective water pipe if the respective risk factor of microbiological growth is above a respective risk threshold.

An electric water heater is described and wherein the bottom portion of the water holding tank is provided with various forms of electric heating elements to heat the water in the lowermost region of the tank adjacent the dome-shaped bottom wall to a temperature sufficient to prevent the proliferation of bacteria growth such as the Legionella bacteria in such lowermost region. The insulating foam support base of the water heater also provides a thermal barrier to the heating elements while biasing the heating element on the dome-shaped bottom wall in a region to insure excellent heat transfer to the cavitated zone surrounding the dome-shaped bottom wall where sedimentary deposits occur to create a culture medium for bacteria growth. In one embodiment a heating wire transfers heat to the lowermost region from the lower end of the surrounding side wall of the tank and access to the heating wire is provided for connection and removal thereof.

A method of detecting stagnant water includes flowing a water in a pipe and producing electrical energy via the flow of the water. The electrical energy is stored in an energy store. A change of state of the energy store is detected and information about possible stagnation of the water is obtained from the change of state of the energy store. An apparatus for detecting stagnant drinking water includes a generator for producing electrical energy, an energy store for storing that energy, a control and analysis unit which detects the charge state of the energy store and a signal transmitter which emits a signal depending on the charge state of the energy store.

A hot water pulsating alarm system and method for electric or gas-fired water heaters is described. A sensor senses the water temperature in an upper region of the water tank of the water heater and feeds temperature signals to a controller. The controller operates an electromechanical valve connected to the pressurized cold water supply line of the water tank. Upon detecting a low temperature value stored in the memory of the controller, the controller causes a shut-off electro-mechanical valve to close and open in a predetermined sequence and during a predetermined time period. This causes interruptions of hot water being drawn from the upper region of the water tank to feed a hot water supply conduit and creating a pulsating water temperature change in hot water being discharged through fixtures connected to the hot water supply conduit. The pulsating temperature change is detected by a user person having a body part in contact with water dispensed from fixtures secured to the hot water supply conduit and indicating to the user person that the water heater will be shut-off.

A hot water pulsating alarm system and method for electric or gas-fired water heaters is described. A sensor senses the water temperature in an upper region of the water tank of the water heater and feeds temperature signals to a controller. The controller operates an electromechanical valve connected to the pressurized cold water supply line of the water tank. Upon detecting a low temperature value stored in the memory of the controller, the controller causes a shut-off electro-mechanical valve to close and open in a predetermined sequence and during a predetermined time period. This causes interruptions of hot water being drawn from the upper region of the water tank to feed a hot water supply conduit and creating a pulsating water temperature change in hot water being discharged through fixtures connected to the hot water supply conduit. The pulsating temperature change is detected by a user person having a body part in contact with water dispensed from fixtures secured to the hot water supply conduit and indicating to the user person that the water heater will be shut-off.

A heat exchanger includes a fin, the fin including a metal base and a porous anodized layer formed on the metal base. A surface of the porous anodized layer has a submicron-order uneven structure, the uneven structure including a plurality of recessed portions whose two-dimensional size viewed in a normal direction of the surface is more than 100 nm and less than 500 nm.

A controlled system and method for operating a lower resistive heating element of an electric water heater is described to kill bacteria in a lower portion of a water holding tank of an electric water heater. A controller having a timer circuit operates the lower resistive heating element bypassing the control of the thermostat associated with the upper and lower resistive heating element to maintain the lower resistive heating element active during a predetermined sanitizing time period whereby the temperature in the lower portion of the tank is maintained at a predetermined temperature sufficient to kill bacteria. The controller is programmed to override a load shedding function during the predetermined sanitizing time operiod.