A heat exchange system for transferring heat energy to control the temperature of a building comprising: a first heat exchanger having a first and second inlet and a first and second outlet wherein waste water flows through said first inlet of said first heat exchanger and out said first outlet while a water supply flows through said second inlet through said first heat exchanger and out said second outlet so as to transfer heat energy between said waste water and said water supply; and a second heat exchanger having a first and second inlet and a first and second outlet wherein domestic water flows through said first inlet, through said second heat exchanger and out said first outlet while said water supply from said second outlet of said first heat exchanger flows through said second inlet, through said second heat exchanger and out said second outlet so as to further transfer heat energy between said domestic water and said water supply from said second outlet of said second heat exchanger and control the temperature of said building.

A heat exchanging to exchange heat between a first fluid and a second fluid has a thermally conductive conduit with a double wall construction with an inner wall and an outer wall fixed thereto and defining a plurality of leak channels therebetween. Any fluid entering the leak channels is conveyed and detected to indicate a potential breach of the inner wall or outer wall. One of the fluids may be warm waste water and the other fluid may be clean water under pressure to recover heat from the waste water. An interleaving baffle located in the fresh water conduit increases heat transfer.

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, 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.

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 waste water, a heat exchange device for heating cold water supplied from the water supply pipe using the waste water, and a flow rate 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 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, 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.

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.

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 clement (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 heat pump system is disclosed comprising a heat-exchanger extracting latent heat from liquid stored in a reservoir, thereby forming an ice slurry. The heat pump also includes a device for delivering the heat to a heat consumer. The heat pump system includes a random input of extrinsic liquid into the reservoir and a device for removing ice slurry stored in the reservoir outward the system.

A heat exchanger that includes a portion for heat exchange with gray water, a portion for heat exchange with clean water, the heat exchanger being arranged to transfer heat between the gray water heat-exchange portion and the clean water heat-exchange portion during a distribution of water and thereby heat a feedwater to a first temperature, wherein the heat exchanger includes a first heating means arranged to achieve the heating of the feedwater, for heating the feedwater to a second temperature, and wherein the heat exchanger includes a second heating means arranged to keep the clean water heat-exchange portion at a temperature greater than or equal to the first temperature during a period without water distribution.

The shower system has a heat exchanger located in compartment vertically adjacent to the wall of the shower space and closed off by an openable or removable panel. The heat exchanger comprising a helically winding heat exchange conduit with successive windings around a vertical axis in said compartment above the floor of the shower space. A pump coupled to the shower drain pumps warm water to a warm water feed of the heat exchanger, from where it is sprayed on a top winding of the heat exchange conduit. Tap water is fed to the shower head successively via the heat exchange conduit and a heater and/or a mixing element for mixing water from the heat exchanger with water from a supply input for external hot water.