A dual fluid heat exchange system is presented that provides a stable output temperature for a heated fluid while minimizing the output temperature of a cooled fluid. The heated and cooled fluids are brought into thermal contact with each other within a tank. The output temperature of the warmed fluid is maintained at a stable temperature by a re-circulation loop that connects directly to the mid portion of the tank such that the re-circulated fluid flow primarily warms only a re-circulation section of the tank. The other, lower flow rate, section of the tank may be positioned so that it has a cooler temperature and thus serves to increase the efficiency of the heat exchange by extracting extra heat energy out of the cooled fluid before it leaves the tank. Alternatively, the low flow rate section of the tank may be warmer than the re-circulated section, and thus allow the re-circulated section to be cooler than the output temperature of the warmed fluid.

The invention relates to a method for operating a circulation system (10) comprising a heating device having an inlet port and an outlet port for controlling the temperature of water, and comprising a pipe system having a plurality of strings which include one or more sections of a given thermal coupling to the surroundings and are connected by means of nodes, one or more of the pipes of the pipe system being designed as a supply pipe (4, 5, 6), at least one individual delivery pipe (7) connected to a removal point (9) and at least one pipe designed as a circulation pipe (10a) being connected to the supply pipe(s) (4, 5, 6), said method comprising the steps: —setting a water temperature at the outlet port to a value Ta by means of the heating device; —setting a volumetric flow rate at the inlet port to a value Vz, and comprising the following steps: —determining, in particular calculating, a temperature change of the water between the start region and the end region according to a model of the axial temperature change for the first section connected to the outlet port, starting from a temperature start value TMA* and a volumetric flow rate start value Vz*; —determining, in particular calculating, a temperature change of the water between the start region and the end region for each further given section according to the model of the temperature change, subject to the boundary condition that the water temperature in the start region of the given section is the same as the water temperature in the end region of the section to which the given section is connected; and —selecting the value Ta of the water temperature and the value Vz of the volumetric flow rate at the outlet port in such a way that in the end region of each section the water temperature TME is in a specified temperature range around Tsoll, in particular at the inlet port (12a, 14b) the water temperature Tb<Tsoll is set with Tsoll−Tb<Θ, where Θ>0 is a specified value. Furthermore, the invention also relates to a circulation system for carrying out the method.

A smart circulation control instantaneous-heating storage heat exchanger includes a heat exchanger, a cold-water pipe, a hot-water pipe, an internal circulation pipe, and a control unit. The heat exchanger includes a storage space. The internal circulation pipe includes a two-way valve and a circulation pump. The control unit is connected to the two-way valve and the circulation pump. The internal circulation pipe functions to return a part of heated water back to the storage space to enhance thermal conversion efficiency and save energy and improve controllability. Positions for supplying cold water and returning water are made at different sites, and the circulation pump and the internal circulation pipe are used to selectively execute functions of anti-freezing, pre-heating, and heat balancing. An external circulation pipe is additionally included such that by means of the two-way valve and the circulation pump, switching can be made between internal and external circulations.

A water heating and treatment system includes a water heater, a hot water outflow line from the water heater, and a cold water supply line to supply water to the water heater. The cold water supply line includes at least one of an anti-scale device, and a UV sanitation lamp. A mixing station supplies a temperature regulated heated water to one or multiple temperature zones. A mixing station supplies heated water to at least a first temperature zone at a first hot water temperature. The water heater, the anti-scale device, the UV sanitation lamp and the mixing station are contained in a single enclosure having at least one sliding transparent wall through which components can be viewed. A plurality of pipe connections passing through a rear panel of said single enclosure are also described.

Hot water heating system comprising one or more water heaters with at least one water heating mechanism, and a heating-control storage tank generally configured to store heated water in a temperature stratified manner where hotter water tends to be separated from cold water. The heating-control storage tank can receive thermal energy or hot water from the water heater, send thermal energy or water to the water heater as its makeup water, and provide hot water directly to end users. The water heater may or may not be used to provide hot water to end users. The system is electronically controlled using a processor, various sensors, a recirculation pump, and electronically actuated valves. Depending on hot water needs and energy costs, the system controls water heating schedule and amount of hot water stored in the heating-control storage tank by changing system operation modes to minimize energy costs while providing reliable service.

A water heater system includes a water heater having a first water outlet and a second water outlet. The water heater system further includes a flow detection device coupled to the first water outlet to detect a water flow through the first water outlet. The water heater system also includes a flow control valve fluidly coupled to the second water outlet. The flow control valve is configured to control a flow of water through the second water outlet based on whether the water flow through the first water outlet is detected by the flow detection device.

A hybrid tank and tankless hot water system with an inlet bypass and an outlet bypass are configurable between a hybrid heater configuration and an on-demand configuration. In the hybrid heater configuration, the inlet bypass supplies cold water to a cold water inlet of a storage tank and the outlet bypass supplies hot water from an outlet manifold to a recirculation inlet of the storage tank. In an on-demand configuration, the inlet bypass supplies cold water to a cold water manifold for directly providing cold water to hot water heaters and the outlet bypass supplies hot water from the outlet manifold directly to a system hot water outlet. In the bypass configuration, a storage tank and/or recirculation pump are fluidically isolated from one or more hot water heaters to facilitate their maintenance, repair, replacement while still supplying hot water on demand from the hot water heaters.

The present disclosure relates to a heat pump system for transferring heat using a body of water. The heat pump system includes a water pumping system and a heating and cooling loop that directs a working fluid through a heat exchanger where heat is transferred between the working fluid and water from the body of water. The water pumping system includes an inlet line, an outlet line, and a pump. The pump moves the water from the body of water through the inlet line to the heat exchanger then through the outlet line and back to the body of water. A biocide generating device is positioned along the inlet line for providing real-time generation of biocide in the water flowing through the inlet line. A recirculation line directs water from a tap location on the inlet line positioned downstream from the biocide generating device to the water intake.

A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.

A manifoldhead and expansion tank combination is provided. The manifoldhead comprises an outer housing having an inlet channel and an opposed outlet channel extending laterally from the manifoldhead and a connection means, surrounding a third opening from the outer housing, for sealably connecting the manifoldhead to the to the expansion tank. The manifoldhead further includes, secured internally within the outer housing, a baffle plate extending longitudinally within the manifoldhead and having an opening extending through the baffle plate, the opening being preferably aligned with the inlet and outlet channels. The baffle plate extending into AND through the third opening to continue to separate the flow moving through the entire expansion tank into inlet and outlet flows, entering and leaving the third opening. There is also preferably provided another set of baffles extending across the third opening limiting the inlet and outlet flows through the expansion tank. There are also provided recirculation systems for potable water that include a manifoldheaded expansion tank for providing both cool and heated potable water to a building where people live or work.