A hot water supply system includes a water supply pipe for supplying cold water, a hot water supply pipe for supplying hot water heated by a hot water supply device, a drain pipe for draining wastewater, a heat exchange device for heating cold water supplied from the water supply pipe using the wastewater, and a flow control mechanism for controlling, when supplying warm water obtained by mixing cold water heated by the heat exchange device and hot water heated by the hot water supply device, the flow rate of the cold water and the flow rate of the hot water so as to maintain the temperature of the warm water. The heat exchange device is a double-pipe, multi-pipe, coil, or spiral heat exchanger.

A first conduit having a cylindrical upper entrance region with the axis of the cylindrical region oriented vertically, which accepts incoming downwardly flowing hot drain water, a central region of said first conduit below the said entrance region having a conical shape of increasing diameter, reaching a maximum diameter 2-7 times larger than the upper region, the shape then transitioning to a decreasing diameter area of a conical shape, the shape transitioning to a cylindrical lower region with a diameter similar to the upper region diameter; a second conduit for the flow of the shower cold water supply, with a diameter 10-40 times smaller than the maximum diameter of the drain water conduit, and a length 10-40 times longer than the vertical length of the drain water conduit, the second conduit tightly wrapped around the first conduit and in close thermal contact with the first conduit.

An exemplary system is for a facility including a first heating/cooling zone and a water delivery system configured to deliver domestic water to a point of water use. The system generally includes a facility loop having a facility loop refrigerant flowing therethrough, a first zone heat pump configured to transfer thermal energy between the facility loop refrigerant and the first heating/cooling zone, and a first water-source heat pump configured to transfer thermal energy between domestic water upstream of the point of water use and the facility loop refrigerant.

A hot water unit fluid supply control system comprises a switching device coupled to a hot water unit, a rainwater tank and a potable water source. The switching device is configured to selectively switch between a first state, which allows fluid communication between the hot water unit and the rainwater tank, and a second state, which allows fluid communication between the hot water unit and the potable water source. The hot water unit fluid supply control system comprises a control unit configured to: receive fluid characteristic information associated with fluid in the hot water unit from one or more sensors; activate or deactivate a pump of the rainwater tank based on a comparison of a fluid characteristic parameter of the fluid characteristic information with requirements of the hot water unit to thereby cause the switching device to assume the first or second state.

A fluid heating device includes a housing defining an inner volume. A combustion chamber configured to produce heat via combustion such that heat produced by the combustion chamber is transferred to a fluid in the inner volume, and a flue is in fluid communication with the combustion chamber and in thermal communication with the inner volume. An electrical heating device is configured to provide heat to the fluid in the inner volume, and a thermoelectric generator is in electrical communication with the electrical heating device. The thermoelectric generator is connected to the flue such that a heat difference between the inner volume of the housing and the interior portion of the flue enables the thermoelectric generator to generate electricity.

A system and method for controlling microbiological growth in a water system and premise plumbing system which uses stabilized hydrogen peroxide as a disinfectant and maintains water energy matrix control. Maintenance of stable hydrogen peroxide residual in the system in combination with active temperature monitoring enables better control of the water energy matrix and reduction of hot water temperature while maintaining microbiological control.

Provided are a heat exchange method of tap water using a heat exchanger, and the heat exchanger. The content of residual chlorine in the tap water is about 2 ppm or more, the heat exchanger comprises a plurality of heat plates, which comprise ferritic stainless steel, and copper brazing configured to couple the heat plates, and the ferritic stainless steel contains less than about 0.5 wt % of nickel, about 0.1 wt % to about 2 wt % of copper, and about 0.03 wt % or less of carbon.

An electric power system is disclosed herein. The electric power system may manage and store electric power and provide uninterrupted electric power, derived from a plurality of electric power sources, to an electric load. The electric power system may contain an energy storage unit and generator assembly. The electric power system may connect to a power grid and renewable energy sources, and may charge the energy storage unit using the power grid, renewable energy sources, and/or generator assembly. The electric power system may be configured to determine load power usage and environmental factors to automatically and continuously modify a charging protocol to, for example, provide high efficiency and/or self-sufficiency from the power grid. The electric power system may operate entirely off-grid and may provide electricity to the load without interruption to power.

A system of capturing waste heat includes a heat recovery unit (20) having a heat exchanger (35) arranged to transfer heat between a fluid circulating in a refrigerant loop (60) and a fluid circulating in a solar loop (70) and another heat exchanger (39) arranged to transfer heat between the fluid in the solar loop (70) and a fluid circulating in a water loop (50). Controllable first, second, and third three-way valves (V1-V3) provide or prevent, depending on fluid temperatures, an A-B, B-C, and A-C flow path through the valve. The first valve (V1) is arranged in the water loop (50) upstream of the second heat exchanger (39). The second (V2) is arranged in the solar loop (70) upstream of the second heat exchanger (39). The third valve (V3) is arranged in the solar loop (70) between the first and second heat exchangers (35, 39).

The purpose of the present invention is to provide a hot water supplying apparatus which enables supply of hot water by utilizing waste heat of a pipe and a boiler as a heat source if there is a small quantity of residual hot water to use therefor, the residual hot water being required when using hot water of an instantaneous boiler, and a method for utilizing waste heat of a hot water supplying apparatus. The hot water supplying apparatus of the present invention for achieving said purpose comprises: a sensible heat exchanger for heating a heating fluid by means of combustion heat from a burner; a hot water supply heat exchanger for generating hot water by means of a heat exchange between the heating fluid heated by the sensible heat exchanger and direct water, and supplying the hot water to a faucet; and a pump for circulating the heating fluid via a heating fluid flow path which connects the sensible heat exchanger and the hot water supply heat exchanger, wherein the hot water supplying apparatus comprises: a signal reception unit for receiving a final hot water use signal; and a control unit for stopping the operation of the burner on the basis of the signal received by the signal reception unit and controlling the pump to circulate the heating fluid.