A heat supply system with a first temperature detection unit that detects a first temperature of hot water in a tank and a second temperature detection unit that detects a second temperature above the first temperature detection unit. When the first temperature is a first lower limit temperature or less, where a temperature increase operation by a combined heat and power supply device is permitted, a control device operates the combined heat and power supply device and flow state adjustment devices such that a heat medium circulates between the combined heat, power supply device, and hot water storage device. When the second temperature is a second lower limit temperature or less, where a temperature increase operation by a boiler device is permitted, the control device operates the boiler device and the flow state adjustment devices such that the heat medium circulates between the boiler device and hot water storage device.

The present disclosure provides a computer-implemented method of defrosting a heat pump of a water provision system installed in a building, the water provision system comprising the heat pump configured to transfer thermal energy from outside the building to a thermal energy storage medium inside the building and a control module configured to control operation of the heat pump, the water provision system being configured to provide water heated by the thermal energy storage medium to an occupant of the building at one or more water outlets, the method being performed by the control module and comprising: determining, based on performance of the heat pump, an expected start time of a next defrost cycle; and preparing the water provision system before the expected start time of the next defrost cycle.

A water heater includes a heat exchanger. A controllable three-way proportional valve provides a proportionally controllable flow to the hot water inlet of the heat exchanger and a boiler return water outlet. A mixing tank mixes a cold water and a hot water. The mixing tank provides a time delayed mixed water. A temperature sensor is disposed in or on the mixing tank to measure a temperature of the time delayed mixed water to provide a time delayed mixed water temperature. A feedforward control process running on a processor adjusts a proportional operating position of the controllable three-way proportional valve to regulate a temperature of hot water at the hx domestic hot water outlet based on the temperature of the time delayed mixed water temperature. A method for controlling a hot water temperature of a water heater a water heater using a flowmeter based feedforward control are also described.

A heating system and method for heating by means of at least one processing unit having at least one processor for performing computational tasks. A container unit is arranged for holding a medium, wherein the at least one processing unit is thermally coupled with at least a portion of the container unit for transferring thermal energy produced by the at least one processing unit to the at least one portion of the container unit for heating medium inside the container unit.

The concepts relate to reducing energy loss associated with hot water systems. One example can monitor hot water use in a system. Upon completion of the hot water use, the example can recover some of the hot water from hot water lines into a water heater that heated the hot water. The method can also deliver the recovered hot water to the water heater in a manner that affects operation of a heating element of the water heater.

A combined heat and power system, or an energy system, is provided. A four-stroke opposed-piston engine provides efficient power from a generator set or genset. A heat exchange system is provided within the energy system to provide efficient waste heat recovery as the engine is operated.

The concepts relate to reducing energy loss associated with hot water systems. One example can monitor hot water use in a system. Upon completion of the hot water use, the example can recover some of the hot water from hot water lines into a water heater that heated the hot water. The method can also deliver the recovered hot water to the water heater in a manner that affects operation of a heating element of the water heater.

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 hot water system and method are provided. The system includes a tank configured to receive hot water, a heat recovery system for heating water, and a controller configured to use the heat recovery system to maintain the hot water in the tank at a temperature within a predetermined range of temperatures. The method involves receiving a flow of water and heating the water using the hot water system.

A system and method for providing hot water to a point of use such as a shower. Waste warm water from said point of use passes through a heat exchanger, where it initially warms incoming mains water, typically to about 34 C. The initially warmed water is heated to its final temperature, typically about 42 C., in a smart boiler. The smart boiler, which typically has a volume of about 40 liters, comprises two chambers with a flexible barrier therebetween. Each chamber is separately heated as needed. Hot water is drawn from one of the two chambers; simultaneously, the other chamber fills with initially warmed water and is heated to its final temperature. When the volume of water in the chamber from which water is being drawn reaches a minimum, the system begins to fill that chamber and to draw water from the other one.