Abstract: The present disclosure provides a method for controlling rate of heat delivery in a hydronic system, which includes receiving, by a control unit, at least a first temperature, a second temperature from two spatially separated points in the hydronic system and a flow rate. The two spatially separated points correspond to inlet of heat transfer device and outlet of heat transfer device. The method also includes calculating at predefined interval, by the control unit, an actual rate of heat delivery to the heat transfer device based on flow rate and temperature difference between the two spatially separated points. The control unit determines heat delivery rate difference between actual rate of heat delivery and target rate of heat delivery. The control unit adapts flow rate of fluid into inlet of heat transfer device based on heat delivery rate difference to maintain target rate of heat delivery in heat transfer device.

Abstract: A heat source system is to be connected to another heat source system. The heat source system includes a heat source device and a control part. The heat source device includes a water regulation valve configured to regulate a flow rate of supply water flowing in the device and is configured to heat the supply water. The control part is connected to the heat source device, and is configured to acquire flow rate information of the supply water supplied to the other heat source system and the heat source device, to close the water regulation valve when a flow rate of the supply water is 0 or more and less than a first set value, and to open the water regulation valve when the flow rate of the supply water is equal to or greater than the first set value.

Abstract: A method for saving energy by shutting down unnecessary equipment in a water heating system and setting back temperature setpoints to reduce energy losses. The present method is aimed at reducing energy wastage due to unnecessary external recirculation and overly high temperature setpoint for the external recirculation flow when no demands exist for an extended period of time.

Abstract: In a hot-water storage type heating unit 1, a liquid-liquid heat exchanger 15, which exchanges heat between a first hot-water circulation circuit 12 through which hot water stored in a hot-water storage tank 11 circulates and a heating circulation circuit 14 in which the hot water flows from a radiator unit 3 for heating, is disposed above the hot-water storage tank 11, and a circulation pump 16 is disposed in the first hot-water circulation circuit 12 on the downstream side of the liquid-liquid heat exchanger 15. In order to return the gas, which is separated by a gas-liquid separator 17 provided so as to be interposed in the first hot-water circulation circuit 12 between the liquid-liquid heat exchanger 15 and the circulation pump 16, to the hot-water storage tank 11, a return passage 18 which communicates between the hot-water storage tank 11 and the gas-liquid separator 17 is provided.

Abstract: A boiler loop system including a primary-secondary piping loop interface apparatus including a flow diversion device, and a drain valve, and a drain port in branches from a circumferential sidewall. In an embodiment, supply branch piping and return branch piping connect the primary-secondary piping loop interface apparatus to a boiler and provide attachment points for auxiliary plumbing equipment. In an embodiment, the boiler loop is integrated into the primary loop.

Abstract: Apparatus for capturing heat from a stove to enable it to be transferred to a central heating system is disclosed. The apparatus comprises an air-water heat exchanger, the heat exchanger having an air side and a water side and being operative to transfer heat between air on the air side and water flowing in channels in the water side. The apparatus includes an air duct through which air heated by a stove can pass by convection to contact the air side of the heat exchanger and control means operable to control the amount of air flowing to the heat exchanger. The control means may include a fan that can be operated to direct the flow of air to the heat exchanger.

Abstract: A mobile surface heater is disclosed having a heat generation loop and a heat dissipation loop. The heat generation loop can include a heat generating device, a storage tank, and a first pump for circulating a fluid. The heat dissipation loop can be placed in fluid communication with the heat generation loop and includes a ground heating system having at least one heat transfer conduit extending between a supply manifold and a return manifold. A control valve can also be provided to deliver a mixed fluid flow stream to the ground heating system by selectively mixing fluid from the heat generation loop with fluid returning from the ground heating system return manifold. In one embodiment, an electronic controller is provided that operates the mixing valve to maintain a temperature setpoint of the mixed fluid flow stream and to maintain a minimum entering fluid temperature setpoint of the atmospheric water heater.

Abstract: A water heater having primary and secondary heat exchanger and a pump to move water between the primary and secondary heat exchangers. The pump may also be used for the purpose of recirculating water within a building. The water heater may be manufactured with a method in which certain steps and components are added to a water heater of a first efficiency to arrive at a water heater having a second efficiency greater than the first efficiency. The additional steps and components may include attaching a condensing recuperator to a traditional power vent water heater.

Abstract: In a hot-water storage type heating unit 1, a liquid-liquid heat exchanger 15, which exchanges heat between a first hot-water circulation circuit 12 through which hot water stored in a hot-water storage tank 11 circulates and a heating circulation circuit 14 in which the hot water flows from a radiator unit 3 for heating, is disposed above the hot-water storage tank 11, and a circulation pump 16 is disposed in the first hot-water circulation circuit 12 on the downstream side of the liquid-liquid heat exchanger 15. In order to return the gas, which is separated by a gas-liquid separator 17 provided so as to be interposed in the first hot-water circulation circuit 12 between the liquid-liquid heat exchanger 15 and the circulation pump 16, to the hot-water storage tank 11, a return passage 18 which communicates between the hot-water storage tank 11 and the gas-liquid separator 17 is provided.

Abstract: A boiler loop system including a primary-secondary piping loop interface apparatus having unitary construction including a flow diversion device, and a drain valve and a drain port in branches from a circumferential sidewall. In an embodiment, supply branch piping and return branch piping connect the primary-secondary piping loop interface apparatus to a boiler and provide attachment points for auxiliary plumbing equipment. In an embodiment, the boiler loop is integrated into the primary loop.

Abstract: A radiant heating system comprising a substantially hollow housing having detachable baffle plates internally positioned within the housing. The housing has an inlet and outlet for a flow of coolant to enter into and leave the housing, and a top plate sealing the upper surface of the housing has openings defined therein for insertion of heating elements to project into the housing and be in direct contact with the coolant to heat it. The inlet and the outlet are interconnected with piping to form a closed fluid flow circuit. Two or more baffle plates are used to increase turbulence of the coolant within the housing as it flows through, and temporarily keep coolant in the housing longer to heat it.

Abstract: A hot-water supply heat exchanger having a mixing valve and a mixing valve integrated adopter are provided to facilitate control of hot water temperature with a simplified pipe structure. A hot-water supply heat exchanger comprises a heat exchange part (100), a heating water inlet (212), a heating water outlet (214), a cold water inlet (222), a hot water outlet (224), and a mixing valve (230). The heat exchange part allows heat exchange between hot water provided from a main heat exchanger (20) with cold water. The heating water inlet draws hot water into the heat exchanger. The to heating water outlet discharges the hot water heat-exchanged by the heat exchanger. The cold water inlet draws the cold water into the heat exchange part. The hot water outlet discharges the cold water that is heat-exchanged with heating water in the heat exchange part. The mixing valve mixes the hot water discharged through the hot water outlet with cold water provided from the cold water inlet.

Abstract: A heat transfer system comprises a plurality of cells, a plurality of heating elements, and a controller for independently controlling the plurality of heating elements. The heat transfer system is capable of maintaining a fluid temperature within a predetermined range. A second pump pumps fluid through a heat exchanger in operative relationship with the blower upon a call for heat.

Abstract: An air elimination device with a hydraulic separator in a compact format that eliminates numerous separate field installed components and connections and can be cost effectively made by means of spun, bent, bored, milled sheet copper or brass sheet, copper or brass tube or rod utilizing brazing, soldering and threading of parts. The device can be made to include a manifold, particularly with compact end suction pumps and can serve as a transition adaptor to other modular mechanical components.

Abstract: A method is provided for adjusting several parallel connected heat exchangers supplied with a coolant medium. The aim of the invention is to simplify the adjustment. For this purpose, the method consists in a) determining a specific value of heat requirement for each heat exchanger in a predetermined time period; b) comparing the specific values of all heat exchangers therebetween and c) in modifying the adjustment of the heat exchanger having the lowest specific value of heat requirement in such a way that the heat requirement thereof is increased.

Abstract: Heating systems including a boiler for heating a heating fluid, a plurality of heating accessories each requiring input of heat, piping connecting the boiler with the heating accessories, at least one of the heating accessories being placed in series relative to at least one other of the heating accessories, and a valve system including a variable speed pump and an associated control system for varying flow of the heating fluid from the boiler. Each heating accessory is configured such that heating fluid from the boiler delivered through the piping to each successive heating accessory provides heat to each heating accessory and the heating fluid is returned to the boiler at a sufficiently low temperature (e.g., no more than about 120° F.) so as to allow the returned heating fluid to be used to condense water out of flue gas generated by the boiler so as to maximize the efficiency of the boiler.

Abstract: Disclosed is an automatic switching two pipe hydronic system for conditioning a space. In one embodiment the two pipe hydronic system enables automatic switching from a first mode of operation to a second mode of operation or vice versa in a reduced span of time. The present invention saves fuel, energy and water, when there are lower load conditions that affect boilers, chillers, and cooling towers. In another embodiment, the present invention provides a system for simultaneously heating and cooling a first portion and a second portion of a space by utilizing a plurality of boilers, chillers, heat exchangers, condenser pumps and closed loop pumps by using a plurality of sensors indicating the temperatures inside and outside the space and a controlling module controlling the operation of the system. The present invention can be easily achieved by making minor configurational modifications to existing systems thereby increases system versatility.

Abstract: Disclosed herein is a hot/cold water supply system with an improved control part. Cold water that has remained in a pipe is re-circulated through a circulating water pipe and is re-supplied into and heated by a boiler rather than being discharged out of a faucet, and the temperature of the water is adjusted in a thermo-and-geared valve to a temperature preset by a user so that water with a low temperature deviation can be supplied to the user. Further, an excessive load is prevented from being applied to the thermo-and-geared valve. Water of different temperatures preset by users can be supplied to corresponding control zones. A sudden deviation in temperature can be prevented when the boiler re-ignites. When the temperature of water reaches a preset temperature, a control panel indicates it to the user on a display and/or by providing a sound, thus making it more convenient to use.

Abstract: A primary-secondary loop piping system includes at least one boiler in fluid communication with a primary piping loop and at least one primary loop pump in the primary piping loop. At least one secondary piping loop branches away from the primary loop and returns downstream to the primary loop via a pair of closely spaced tees in a primary/secondary piping loop interface apparatus. The primary/secondary piping loop interface apparatus is of unitary construction and includes a secondary loop shut-off valve, drain valve and drain port in each branch of each secondary loop in which it is installed.

Abstract: A primary-secondary loop piping system includes at least one boiler in fluid communication with a primary piping loop and at least one primary loop pump in the primary piping loop. At least one secondary piping loop branches away from the primary loop and returns downstream to the primary loop via a pair of closely spaced tees in a primary/secondary piping loop interface apparatus. The primary/secondary piping loop interface apparatus is of unitary construction and includes a secondary loop shut-off valve, drain valve and drain port in each branch of each secondary loop in which it is installed.

Abstract: A heating system comprising a first flow pipe and a second flow pipe which are interconnected at ends thereof to form a closed loop fluid flow circuit. A housing having a passage extending therethrough for passage of water through the housing is interconnected with the fluid flow circuit, and a pump is utilized to circulate water through the fluid flow circuit. The housing provides at least one opening defined therein separate from the passage, and at least one heating element is inserted therein, projecting into the housing, so as to be in direct contact with the water therein. The heating element is powered by a power source for enabling the heating element to heat the water and operate the pump. Radiator panels are connected to the fluid flow circuit, to radiate the heat from the heated water flowing in the fluid flow circuit to a space heated by the heating system.

Abstract: A method of cooling a plurality of devices operated in parallel and heated by relatively long duration pulses using a single coolant flow channel to the devices in series that transports the heat from the several devices in a contiguous series of heat pulses to the heat exchanger.

Abstract: Disclosed is a heating system. The heating system includes a heating element configured to heat a working fluid and a circulation system configured to circulate the working fluid through a circulation loop. The heating system further includes an energy storage device configured to store and discharge energy. The discharged energy comprises electricity delivered to the heating element and the circulation system. In addition, a recharging element is configured to charge the energy storage device.

Abstract: A heating system in which a warmed fluid is circulated through a delivery network space heaters to provide space heating, further comprising a thermal store and means arranged to circulate the warmed fluid through the thermal store during a heating shut down sequence to recover heat from the warmed fluid.

Abstract: The invention relates to a device for connecting a heating apparatus to the feed and return sections of a heating system of a building, wherein there is a water inlet channel with an inlet and an outlet connection, wherein the feed section of the heating system can be attached on the inlet connection, and the inlet of the heating apparatus can be attached on the outlet connection, there is a water outlet channel with an inlet and an outlet connection, wherein the outlet of the heating apparatus can be attached on the inlet connection, and the return section of the heating system can be attached on the outlet connection, and there is at least one connection, in particular a side connection, to the water inlet channel and/or to the water outlet channel between the inlet and outlet connections for a measuring device, pump, and/or a connecting hose.

Abstract: Disclosed is a fluid heater that can be used as a heater in a residence or an industrial facility or that can be used to heat water in fishery, agricultural, and transportation industries. In particular, a fluid heater heats a fluid using a multi-channel structure of the flow of fluid passing through a branching system, instead of using additional fossil fuels. The generation of vibration and noise while heating the fluid is suppressed.

Abstract: The present invention relates to a heating system using a fireplace which includes a combustion room having a discharge hole installed at the wall body of a dwelling house comprises a water tank installed within the combustion room of the fireplace and having water therein; and a pipe with a predetermined length flatly placed with a zigzag type under the bottom surface with a constant area at the neighborhood of the fireplace, the inlet and outlet of the pipe communicated with a side of the water tank, which the water discharged from the water tank through the inlet is circulated along the pipe with a predetermined length, then returned to the water tank through the outlet of the pipe, whereby the warmth at the bottom surface of the room is maintained by the circulated warm water.

Abstract: According to the present invention, hot water having a desired temperature can be generated in a short time by forcibly mixing low temperature water with high temperature water, the capacity of a hot water storing tank may be a about half of that of a conventional hot water storing tank, and a water heater can be downsized and made lightweight, and the manufacturing cost and installation cost thereof can be saved. A hot water storing tank 1 has a water supply port on a base plate 2B side, and a water supply port 4 on a top plate 2C side. A suction port 14 is formed in the hot water storing tank 1 so as to be positioned at the same height as or lower than the water supply port 3, and a jet port 15 is formed in the hot water storing tank 1 so as to be positioned in the vicinity of the water supply port 3.

Abstract: A multi-stage pressure distribution and pressure regulation system. The system includes at least one heating and cooling load having a supply side and a return side, a heat source supply system for supplying thermo-fluid to the at least one heating and cooling load, and a booster pumping system including at least one booster pump for transferring the thermo-fluid from the heat source supply system to the supply side of the at least one heating and cooling load for maintaining a predetermined head pressure. The multi-stage system also includes at least one pressure regulating system including at least one pressure reducing and sustaining device for reducing the pressure of the thermo-fluid flowing from the return side of the at least one heating and cooling load and sustaining the pressure at the predetermined head pressure.

Abstract: Decentralized centrifugal pumps (62) with variable speed drivers located at cooling or heating coils (74) are utilized to circulate and regulate liquid through the coils, main supply line (42), and main return line (48). Pump speed is controlled to satisfy temperature or pressure settings of a control agent served by the coil. Central distribution pumps, modulating control valves, and balancing valves are no longer required to circulate and regulate the flow. Without the balancing valves and control valves, there will be less pressure drops and waterpower losses in the piping system. Thus, the decentralized pumping system will require less pump power and energy consumption than the central pumping system.

Abstract: A multiloop temperature-control system has a hydraulic bus connected to a plurality of loops for the temperature-control medium and respective hydraulic modules connected to the hydraulic bus, and through the hydraulic bus, to these loops. Plug connectors join each hydraulic module with an electrical supply and control module and the supply and control modules in turn are connected by plug and jack connectors to an electrical bus.

Abstract: An air purging circulator is provided with a frustoconical reservoir, which promotes separation of dissolved and captured air form the water in a hydronic home heating system, to prevent stalling of the circulator and reduction or elimination of noise associated with air contained in the hydronic system.

Abstract: The invention concerns an assembly wherein a tank connects a return orifice to a delivery conduit via pumps. The tank is further connected to a surge tank. The tank is mounted in a steam proof chamber heat-insulated inside but having an air gap separation around the tank. Components are mounted sealed through the chamber. A filter subdivides the tank into a lower return chamber and a higher starting chamber.

Abstract: A control system for the room temperature in large area heating systems comprises a feed-line manifold and a return-line manifold and for each heating loop an electrically activated throttle valve. A control-unit automatically adjusts the throttle degree of each heating loop so that the temperature difference between the feed-line temperature and the return-line temperature of each heating loop is the same.

Abstract: An air purging circulator is provided with a reservoir on the suction side of an impeller chamber in a circulation pump, to allow circulating water to reduce its velocity, and remove air from the lowest pressure point in the system, the suction side of the circulator, where the least amount of dissolved air is present in the circulating water, so that entrained air in the water is released, and vented from the system. The flanged inlet and outlet apertures of the pump housing are axially aligned, and preferably are located at one end of the pump housing opposite from the motor, to allow convenient installation in retrofit of existing systems. Separation media, such as marbles, wire mesh, or crumpled wire, to further slow the water flow and enhance separation of the air from the water, can be provided in the reservoir.

Abstract: A hydronic heating system having a source of hot supply water and a reservoir of cooler return water, a main hot supply water circulation path (loop) from the supply water line to the return water line including a pump maintaining continuous flow of hot supply water through the main loop, a satellite injection water connection and a satellite return water connection along the main loop, a satellite distribution station including a satellite heating loop, a satellite supply header and satellite return header at opposite ends of the satellite heating loop and a satellite station pump having an input and an output for pumping satellite water from the satellite return header to the satellite supply header, whereby the satellite water flows through the satellite heating loop, a satellite injection water line from the satellite injection connection to the satellite pump input and a satellite return water line from the satellite pump output to the return connection along the main loop, whereby heat from the main loo

Abstract: A method of operating a fluid control system and a distribution valve thereto. The fluid control system comprises a heat source (1) for a heat medium and several distribution valves (6) for distribution of heat medium to several heat consumers (8). Cold return heat medium from each heat consumer is returned to the heat source via a pump (10). To each distribution valve is transmitted warm heat medium from the heat source and cold return heat medium, which are mixed in the distribution valve in accordance with the heat requirement of the corresponding heat consumer. The fluid flow to each heat consumer is constant and is adjusted at the installation of the fluid control system. Thence, the fluid flow is maintained constant and the mixture ratio is adjusted independent of the fluid flow. This means that the fluid flow pump will work under constant flow leading to constant pressure over the pump.

Abstract: A hydronic heating system having a source of hot supply water and a reservoir of cooler return water, a supply water line from the source, a return water line to the reservoir and a multitude of heating loops through which water flows to deliver heat, including: a main distribution station having a supply header, main heating loops, and a return header with a pump compelling circulation within the main station so that heat from the source flows to the main heating loops; and one or more satellite distribution stations, each with a supply header feeding water to satellite heating loops, and a satellite return header and pump compelling circulation within the satellite station; and a satellite injection water line and return water line for circulating some hot water from the main station to each satellite station so that heat from said main station flows to each satellite station.

Abstract: A hot water supply system is provided, which includes a ring pipeline which extends through a water heater and in which water circulates, before going through tap pipelines to taps. The circulation pipelines have a substantially smaller cross-section than that of the tap pipelines. The circulation pipelines extend, for a portion thereof, in the interior of the tap pipelines before terminating openly in a region of a tap. A pipe branch piece is included, which is in the form of a continuous pipe and forms a component of the tap pipeline. A branch pipe of the pipe branch piece receives the circulation pipeline. The branch pipe forms an acute angle with the tap pipeline, with the angle being opened opposite to the flow direction in the tap pipeline. The section of the circulation pipeline, which extends to the tap, is inserted endways into the branch pipe, while the remaining section of the branch pipe joints at the branch pipe and at the ring pipeline.

Abstract: A pool heating and circulating system incorporates an internal combustion engine that drives a pump for developing a flow of water. The internal combustion engine has associated therewith an exhaust pipe which is connected to a heat exchanger. An outlet of the pump is also connected to the heat exchanger such that the water extracts the heat generated by operation of the internal combustion engine. The water flowing out of the heat exchanger is then delivered to a filter and a return line. A heat insulating shield is provided about the exhaust pipe to shield the exhaust pipe from excess exposure to cool air. A bypass line can be provided between the outlet of the pump and the heat exchanger so that water can bypass the heat exchanger and flow directly to the return line and filter when it is determined that the pool water temperature is at a desirable temperature. A valve is actually positioned in the bypass line to vary the flow through the heat exchanger.

Abstract: A portable water heater unit is used to warm a source of ambient temperature water for field use. Warm or hot water is provided for food warming, making hot beverages, showering, and article washing purposes. The unit comprises a housing, a water heater mounted within the housing, a hot water holding tank mounted within the housing, an optional heat exchanger positioned in the hot water holding tank and a temperature control mixing valve operably associated with ambient and hot water lines. An ambient water inlet line leads from an external source of ambient temperature water to the water heater. A hot water line leads from the water heater to the holding tank. Water within the holding tank is directed to an external use source or is continuously recirculated back through the water heater and to the holding tank. An inlet line and an outlet line connected to the heat exchanger within the holding tank is used to supply hot water to make coffee, tea, soup or similar hot drink/food products.

Abstract: A primary-secondary circuit hydraulic interface is disclosed for use in chilled water and hot water systems in which a suction manifold header is used to tie in the secondary return water, the primary supply water, and the suction side of the primary and secondary pumps. The hydraulic interface is installed within the suction manifold at the location where the secondary return water enters the suction manifold. The hydraulic interface allows the bypass water (which is excess primary supply water) and the secondary return water to easily enter the hydraulic interface into a downstream portion of the manifold through large openings and forces the two streams of water to collide together, thereby ensuring a turbulent mixing to take place. The hydraulic interface forces the mixed water to exit the hydraulic interface through much smaller openings into a downstream portion of the manifold, thereby ensuring that the bypass water and secondary return water are thoroughly blended together as they exit.

Abstract: A method and apparatus for saving energy in a chilled water air conditioning system employing secondary pumping for supply chilled water and primary pumping for return chilled water wherein the primary pumping is eliminated comprising directing all of said supply chilled water to the secondary pumps and eliminating any flow of return chilled water through the secondary pumps.

Abstract: A pulsing combustion device is disclosed including a combustion chamber with a poppet valve mounted for reciprocation in the combustion chamber. A pressurized combustible mixture is supplied to the poppet valve with the combustion gases ignited in the combustion chamber. The poppet valve is reciprocated in the combustion chamber by the pressure of the pressurized combustible mixture and the pressure of the combustion gases. The poppet valve regulates the flow of the combustible mixture into the combustible chamber. The pulsing combustion device may be utilized in a steam cleaning device wherein the pulsing combustion device is surrounded by a flow of liquid.The pulsing combustion device may also be utilized for home heating with a fluid heated by the combustion device.

Abstract: An improved forced-liquid flow, circulatory system for removing gas entrained or dissolved in the liquid. The system includes a circulatory liquid-flow network and means for forcing the liquid to flow through the circulatory network. A by-pass line is situated around the region where the lowest gas solubility in the liquid occurs in the circulatory network. Such lowest gas solubility occurs at the point of generally highest temperature and lowest pressure, as determined most precisely by Henry's Law. Gas-liquid separator means is located in the by-pass line. The separator means separates the gas from the liquid and expels the gas from the circulatory network.

Abstract: A selected segment heating system including: means for heating a fluid; conduit means for conducting the fluid from the outlet to the return inlet of the means for heating through a plurality of areas; means, interconnected with the conduit, for moving the fluid through the conduit; gauging means for operating the means for moving to move a segment of the heated fluid in the conduit as far as the return point of the farthest area to be heated; and delay means for suspending operation of the means for moving for permitting a predetermined heat exchange to occur between the heating fluid and the air in the area to be heated.

Abstract: In contrast to reducing the temperature of the heat exchange medium or water so as to conserve on fuel consumption in response to an externally located thermostat or the like upon the occurence of favorable ambient weather conditions, said reduction in accordance with the present invention is, instead, made based on nominal operation of the pump circulating said heat exchange water. The within control that is exercised over the temperature of the heat exchange water to take advantage of mild ambient weather conditions is thus not dependent upon the specific location selected for the thermostat, which location may have more sun and less wind than the spaces or zones being heated. In this and other ways, as hereinafter described, the supervision of the pump provides an accurate and effective control for a hot water heating system that significantly contributes to savings in fuel consumption, but without adversely affecting heating comfort.

Abstract: An electric control device for a central heating boiler which is provided with a water pump or an air ventilator (6), a burner with an electrically operated shut-off valve (5) and an electric control circuit comprising a supply transformer (1) and a series circuit connected to the secondary winding of said transformer and composed of the control winding (4) of the shut-off valve (5), the contact of a room or regulator thermostat (3) and, if present, the contact of a maximum thermostat (2) and in which the water pump or air ventilator (6) is connected in parallel with the primary winding of the supply transformer. The control device comprises a circuit to be connected to the contact of the room or regulator thermostat (3) including a high resistance value series resistor (R.sub.s) to be connected into the mains supply circuit of the boiler, a relay (13) with a normally open contact (k) connected in parallel to said series resistor (R.sub.

Abstract: A system for improving efficiency and effecting fuel conservation in buildings with multiple units heated by forced hot water from a central gas-fired boiler. Each unit or apartment is provided with a circulator pump in the return water pipe and an associated gas valve and meter. When the user in a unit turns on the heat, the circulator pump in that zone is activated to automatically open the associated gas valve which is operated by means of hydraulic pressure differential. The gas from all units flows to a common gas reservoir for discharge to the boiler.

Abstract: A compact heating and cooling system in which air ducts are connected to a host exchanger system through which a coolant fluid from a condensing unit or a heating fluid from a compact water heater is selectively directed by a control circuit so that the system may be mounted outside a building to be heated and/or cooled.