A method for controlling ozonation in a water supply system including an ozonator, a controller functionally connected to the ozonator, a flow meter configured for detecting a flowrate through the water supply system, a valve configured for turning on or off of the water supply system, the method including using the controller for; determining at least one event from flowrate data of the flow meter over a time period of a plurality of days, the at least one event including a time span of a day in which the flowrate remains below or at a threshold value over the time span of a day within each day of the plurality of days; determining overlaps of the at least one event of all days within the time period; determining a frequency of the overlaps of the at least one event over the time period and determining a requirement for ozone.

An aspect of some embodiments of the current invention relates to an integrated system for heat distribution among a plurality of users. In some embodiments, the system includes a separate automatic control of heat distribution to each user and/or separate billing to each user. For example, a system may supply hot fluid to a plurality of apartments in a building and/or in multiple buildings. Optionally, each apartment has separate remote controlled valves controlling flow of heated fluid to the apartment and/or a sensor sensing how much heat enters and leaves the apartment in the hot fluid. In some embodiments, a processor controls the valve and/or receives data from sensors. The processor optionally controls devices that generate and/or store and/or dissipate heat. Optionally the processor predicts energy availability, costs and needs controls valves and/or devices to provide for predicted and/or unexpected needs while reduce cost of the energy.

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.

The invention relates to a container (1) for recovering the heat energy of wastewater. The container (1) comprises a shell (10) and a continuous spiral pipe (2) for conveying wastewater through the container in a vertical direction. A first heat transfer space for a heat transfer liquid is arranged between an outer shell of the spiral pipe (2) and the shell (10) of the container (1), and a second heat transfer space is arranged inside the spiral pipe (2). The shell (10) is provided with at least one openable inspection hatch (6) having fastened thereto a manifold (7) as well as a shell and tube heat exchanger (3) having its inlet and outlet ends coupled to said manifold (7). The spiral pipe (2) consists of acid-proof or stainless steel and its internal surface is adapted to have a higher chromium content than the other parts of the spiral pipe's wall.

Systems and methods are disclosed for exchanging thermal energy between a drain liquid and a source liquid for heating or cooling of the source liquid. One method for heating a source liquid may involve transferring heat from a drain liquid using a heat pump. A system may include a refrigerant, a source liquid and a drain liquid, two or more heat exchangers that facilitate an exchange of thermal energy, and a means for transporting the refrigerant.

The present invention relates to a method and apparatus for transferring heat energy from a waste-liquid, wherein the apparatus (100) comprises at least one heat exchange element (107) for transferring heat energy from waste liquid in a first container (101) to a first target fluid, at least one heat pump element (111) for transferring heat energy from waste-liquid transferred from the first container to the further container (102), at least one selectively operable exit-valve element (115) for selectively providing at least one fluid communication path for allowing waste-liquid to exit from the further container, and at least one controller element for selectively operating the heat pump element to transfer heat energy from waste-liquid in the further container to a further target fluid and/or for selectively operating the at least one selectively operable exit-valve element.

A gray water heat recovery apparatus has first and second passes in counter-flow orientation. The hot side is gray water. The cold side is fresh water. It extracts heat from the gray water. The fresh water is carried in tubing bundles in series immersed in gray water sumps in a unitary cylindrical plastic, mild steel, stainless steel or copper pipe section that defines multiple flow passages. Both ends of the fresh water bundle assembly extend from the same upper end pipe closure, without a pressurized line wall penetration in the walls of the pipe. There is a non-electrically conductive barrier between the fresh water and gray water flow paths. The apparatus has a leak detection circuit and co-operable bypass valves. The lower manifold has gray water passages between the centering ears. The entire assembly is enclosed in a unitary external housing with axially accessible connection fittings.

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.

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.

The invention relates to a heat recovery unit to transfer heat from a gray water source discharged from a bath or a shower to preheat fresh cold water supplying a bath, a shower, a boiler system or hot water heater. The heat recovery unit comprises an inner tube, an outer tube, a non-return valve, an anode, deflectors as well as associated piping and fittings. Fresh water from a pressurized public network or well flows through the inner tube while the gray water flows between the inner and outer tubes. The non-return valve installed in the fresh water pipe prevents contamination of the drinking water system. A translucent pipe may be installed in a section of the gray water piping system to detect any leaks. An insulated jacket may be placed around the unit to reduce heat loss. The heat recovery unit may be used in domestic, commercial, industrial and institutional buildings.