Abstract: A cast metal heat exchanger (e.g. of iron or aluminum) for a hot water boiler having a plurality of flueways and waterways and which is rectangular in plan view down onto the flueways with the waterways extending parallel to the minor rectangular axis. A method of manufacturing a cast metal waterway section of cuboid volume less than 4500 mls for a heat exchanger (which comprises casting the metal into a mould with the waterway core vertically disposed. A heat exchanger comprising a plurality of such sections can be formed integrally by vertically casting such a plurality simultaneously in one mould.

Abstract: An automatic flue gas heat recovery system for supplementing or replacing a conventional, separate hot water system. In the example described, the heat recovery system is applied to a pizza restaurant where large quantities of heat energy are normally wasted up an oven chimney stack, and large quantities of hot water also are required for restaurant operations. An electric motor driven pump circulates water in a closed loop between a storage tank and a heat exchanger tube located in the oven chimney stack. A thermostat control automatically starts the pump when the oven heats the chimney stack to an effective water heating temperature. When temperature in the storage tank reaches a predetermined maximum, the thermostat control stops the pump, opens a drain valve, and dumps water quickly and completely from the heat exchanger tube. Three different embodiments are shown and described illustrating systems with one or more storage tanks and one or more pumps.

Abstract: An apparatus and method for utilizing the heat of waste gases by exhausting the same at the head of a flue from a source into a heat extractor where the hot gases are caused to move and turbulate about heat exchanger walls to release their heat to such walls before being exhausted downward to the atmosphere so that fluids moved through the heat exchanger may be heated to perform useful work.

Abstract: The heat recuperating water heating system includes a water receiving enclosure to which is mounted a burner to provide a source of heat to the water and the products of combustion from this heat source are carried through a flue which is modified to include a manifold equipped with a continuous doubly wound coil defining inner and outer concentric loops, in turn, connected to a pair of conduits; a water circulator is mounted in one of the conduits and is electrically connected to the burner so that each time the burner operates, the circulator is also set in operation and provides a constant determined flow of water in the coil.

Abstract: Furnace structures having smoke and gas return are disclosed. The structures have a closed circuit combustion gas loop and a closed circuit liquid heat transfer loop. The two loops are circulated countercurrent to one another so that maximum heat transfer efficiency is achieved and exhaust emissions are reduced to a minimum.

Abstract: This invention relates to a system for reclaiming or recovering heat which would otherwise be lost from a heating plant. The invention accordingly relates to a heating plant incorporating a plurality of boilers, including a stand-by boiler, there being means for supplying fuel and air to at least one of said boilers, except for the stand-by boiler, and flue gas exhaust ducts associated with each of such boilers. The improvement according to the invention is a waste heat recovery system wherein the flue gas exhaust duct from said at least one boiler is operatively connected to the stand-by boiler for the circulation of hot flue gases therethrough in contact with its heat exchange surfaces thereby to effect the heating of water passing through the stand-by boiler thereby to recover a portion of the heat energy in the flue gases.

Abstract: A heating system including a hot water heater and an air duct distribution system employs a housing having a heat exchanger located within its interior in association with a blower. Water conduits lead between the heat exchanger and the hot water outlet and the cold water inlet of the water heater. Water is passed from the hot water outlet of the water heater to the heat exchanger through a water conduit and then returned to a second conduit which passes through a pump to the cold water inlet of the water heater. The pump forcibly moves the water through the above circuit. Heat is exchanged from hot water flowing through the heat exchanger to air which is passed through the heat exchanger by a blower. After being heated the air is forced into the air duct for distribution. The system can be augmented with a second heat exchanger placed in the flue of the water heater.

Abstract: This device is a box unit, which is attached to the furnace exhaust, between the furnace and chimney. It consists primarily of a unit having, at its top, a reservoir containing fluid. Below the reservoir is an arrangement of tubing, through which the fluid is pumped, and exposed to extremely high temperatures. The unit further consists of a baffle, which causes the heat and exhaust fumes to pass upwards over the tubing, to surround the reservoir, and then downwards, and out of the chimney.

Abstract: Flue gases from a glass-melting furnace, after passing through an elevated recuperator, descend through a vertical cooling column into a horizontal convective boiler before being exhausted into a smokestack. Entering water, circulating essentially in counterflow to the flue gases, is preheated in an exit compartment of the boiler and passes via a flow regulator into the main boiler chamber and thence into a bank of vertical pipes on the periphery of the column. On rising through these pipes, the water is partly converted to steam which is superheated in an entrance compartment of the boiler before being fed to a load, the remaining water being returned to the boiler chamber.

Abstract: A heat recovery device for boilers with a blower-type burner. A heat exchanger is located in the stack gas stream and through which is passed a medium to be heated and comprises a pot-shaped vessel (2) which can be inserted into the stack gas duct and is closed on all sides. A stack gas inlet (4) leads into the upper zone of the vessel (2) and at least one stack gas outlet (6, or 30 or 31) leads out of the upper zone of the vessel (2) at a distance from the inlet. A substantially vertical partition wall (7; 21) is located in the vessel (2) and extends downwards from the cover (8) of the vessel (2) and ends at a distance from the bottom (9) of the vessel to interrupt the direct stack gas path from the inlet (4) to the outlet (6). Thus, a siphon-type stack gas path is formed with an inlet chamber (10; 26) and an outlet chamber (11; 27). A draft-interruption damper (15; 32) is fitted in the outer vessel wall in the zone of the outlet chamber (11; 27).

Abstract: A closed-loop heat-transfer system includes in combination an exhaust chamber for positioning in series with a chimney flue of a heating system wherein the exhaust chamber has an exhaust inlet and an exhaust outlet opening adapted for connecting the chamber to the chimney flue. The exhaust chamber includes a first heat exchanger having a fluid inlet opening and a fluid outlet opening and a coiled conduit positioned interior to the chamber interconnecting the fluid inlet and outlet openings. The heat-transfer system also includes a second heat exchanger for positioning in a location remote to the chimney flue, and the second heat exchanger also has a fluid inlet opening and a fluid outlet opening. A conduit couples the fluid openings of the first heat exchanger to the fluid openings of the second heat exchanger to form a closed circulatory loop for a heat-transferring fluid.

Abstract: An enclosure containing rotating blades for mechanical stirring of gaseous fluids may be a heat exchanger, flue gas energy recovery device, gas generator or combustion device. A high rotational stirring velocity increases the convective heat transfer rate, rendering it independent of the lower throughput velocity of primary fluid which can be controlled independently of the stirring speed. Primary fluid is isolated from a secondary fluid by a thermal transfer surface which is continuously swept by the swirling primary fluid and which may be the peripheral wall of the enclosure or a flow tube located proximate the peripheral wall. In one embodiment, swirling is achieved by radially-extending blade assemblies secured to a rotatable shaft at longitudinally spaced locations to establish discrete swirling zones in which fluid recirculates from the shaft outwardly, along the wall, and back toward the shaft.

Abstract: A system for producing hot water for a residential dwelling by recovering heat from the hot combustion gases in the flue and chimney of the dwelling's heating system. The system uses the usual hot water tank and furnace of the dwelling without any substantial modifications thereto. The hot water tank is located in an upper floor of the dwelling and is connected to the furnace which is located on a lower level by a first section of pipe which extends from adjacent the water heater to the furnace flue within the chimney. A cold water supply is connected to the first section of pipe by a second section of pipe which also extends through a portion of the chimney and the furnace flue to recover heat from the hot combustion gases passing therethrough. The heated water in the sections of pipe flows into the hot water tank through the usual cold water inlet line for subsequent discharge from the tank throughout the house.

Abstract: An apparatus for recovering energy that can be incorporated in the flue gas discharge duct of a gas or oil fired heating installation which uses a liquid circuit to transfer heat. The apparatus is comprised of supply and discharge connections for the flue gas, a heat exchanger to be incorporated in the liquid circuit, a condensate collection and discharge device, and a fan to force the flue gas flow past the heat exchanger.

Abstract: An apparatus for the recovery of heat from waste gases is disclosed. The apparatus generally comprises a heat recovery coil which is located above the combustion chamber of a furnace and in the path of waste gases psssing through a flue, a circulation pump and an expansion manifold. The apparatus is equally useful in new as well as retrofitted applications.

Abstract: An energy recovery device can be installed in the exhaust of heat producing equipment. The device includes a conduit having a main and bypass chamber. Also included are fluid conducting coils which are mounted within the main chamber for passing fluid therethrough. A relief device operates to connect in parallel the main and bypass chambers in response to a differential pressure therebetween exceeding a predetermined magnitude. Therefore it is estimated that approximately 50-85% of wasted energy through the flue pipe can be recovered and utilized for said system depending upon the size of the unit.

Abstract: A boiler economizer includes a first heat exchanger disposed in a boiler flue and a second heat exchanger which is external. Boiler feedwater is delivered in series to the first and second heat exchangers before passage to the boiler. A flow controller directs a first portion of the boiler feedwater directly to the first heat exchanger and a second portion is first delivered through the second heat exchanger where it is passed in a heat exchange relation with the feedwater exiting the first heat exchanger. The flow controller is positioned by a temperature transponder which is responsive to the temperature of the discharge flue gases and the feedwater entering the first heat exchanger.

Abstract: Method and apparatus for improving convective heat transfer by mechanically stirring fluid over the outer surface of a heat exchanger. A stirring mechanism is described which revolves rapidly around a heat exchanger surface in a stream undergoing heat transfer. During rotation, the stirring mechanism is supported near an end of the stirred heat exchanger by a central bearing and drive means. It is also supported over an extended length of the stirred heat exchanger surface by the hydrodynamic action of the stirring mechanism relative to the heat exchange surface without need for an additional central support bearing. The stirring mechanism uniformly turbulates the fluid film over the outer surface of the heat exchanger where heat transfer resistance normally occurs without imposing a pressure drop in the fluid stream undergoing augmented heat transfer. Compact and inexpensive heat exchangers are described which may be used in refrigeration, heating-cooling, and energy conservation systems.

Abstract: A system for recovering heat from combustion flue gas, which transfers heat from the flue gas into combustion-supporting air, which is then used to burn a fuel in a combustion zone in a furnace or the like, so that useful heat is generated and a hot combustion flue gas is formed. Two heat sinks are provided, each for alternate absorption of heat from the hot flue gas, and desorption of heat into ambient combustion air so that the air is preheated. A reversible fan or blower is associated with each sink. The hot flue gas is passed successively through one heat sink and fan to atmospheric discharge for a finite time interval, while concomitantly passing cold and usually ambient combustion air successively through the other fan and heat sink so that the air is heated and a preheated combustion air stream is formed, which is subsequently passed to the combustion zone. After the finite time interval, the reversible fans are reversed for another finite time interval usually equal to the first time interval.

Abstract: A furnace with a combustion compartment and a heat exchanger compartment connected by a channel having a secondary air inlet for efficiently burning wood and absorbing the heat of combustion.

Abstract: In the boiler plant the flue gases coming from the firing space undergo division into at least two part-currents which are cooled to different degrees by giving up heat to a heat exchange medium and are then mixed together partly for producing a gas current with a desired temperature dependent on the rates of mixing of the two part-currents. The mixed current is then taken up by a heat user. Parts of the flue gases not going to the heat user are run through all heat absorbers of the system as far as the off-gas stack. The amounts of the part-currents of flue gases, used for forming the gas current with the desired temperature of mixing, are controlled dependent on the mixing temperature.

Abstract: A lightweight, modular chimney heat economizer adapted to replace a portion of the chimney for a combustion heat source in a building. The economizer includes a plurality of flue tubes having their ends welded to a pair of spaced apart tube sheets. Connected between the tube sheets and surrounding the flue tubes are inner and outer casings between which are sandwiched a layer of nonflammable insulation. The upper and lower tube sheets include outwardly extending flanges adapted to enable the economizer to be removeably secured in place so it may be easily installed and easily removed for maintenance and repair. The casings are provided with expansion joints. The top ends of the flue tubes may be flush with or recessed from the top surface of the upper tube sheet, and an upwardly projecting flange may surround the upper ends of the flue tubes to encourage condensed products from the combustion gases to drain into the flue pipes where they may be disposed of.

Abstract: A preheating unit having a water tank provided with bottom, side and top walls. The tank is fitted with a cold water supply pipe and a warm water delivery pipe. A casing encloses the tank and has a side wall spaced from the side wall of the tank to provide a substantially annular insulating space therebetween. A plurality of inner tubes extend longitudinally through the tank and an outer tube is secured to the bottom and top walls to enclose each inner tube. The inner and outer tubes are spaced apart to define annular spaces therebetween. A lower adaptor on the casing connects a first pipe section to the pipe in communication with the inner tubes. An upper adaptor on the casing connects a second pipe section to the pipe in communication with both the inner tubes and the annular spaces.

Abstract: A cooling device for use in tubular hot gas conduits which are made up of a plurality of longitudinally arranged side by side abutting pipes includes a plurality of registers arranged in spaced relationship along the length of the pipe and extending into the pipe from one side thereof into closely spaced arrangement in respect to the opposite side. The registers each include a plurality of U-shaped pipes which are interconnected and arranged in the direction of flow and which are connected externally of the hot gas conduit through respective inlet and outlet headers.

Abstract: A flue gas heat recovery system for dwelling hot water heating system boilers is disclosed. The system comprises a heat exchanger disposed in a flue for exhausting combustion products from the boiler and a circulating pump for circulating cooled water from the heating system through the exchanger to be warmed by the combustion products. The system includes a by-pass line for by-passing the heat exchanger, and control valves for varying the amount of cooled water diverted around the heat exchanger.

Abstract: A preheater unit which includes a chamber for boiler water and a domestic water heating coil is arranged in heat exchange relationship with the exhaust duct of a boiler of a heating system for extracting heat from the flue gases. Boiler water may be shut off to the heat radiating system in the summer although boiler water is fed to the preheater unit both in summer and in winter. The domestic water heating coil within the preheater unit is connected in series flow relationship with the domestic water heating coil interiorly of the boiler. A summer/winter switch is added to the conventional boiler circuitry to enable control of the water circulator by the thermostat in the winter, while the water circulator is operated by the upper limit aquastat during summer operation whenever the burner of the boiler is energized.

Abstract: Freeze protected hot water solar heating apparatus for providing room heating and domestic hot water service comprising a solar heat collector, a water storage tank, a freeze protector, a fuel burning boiler, a heat exchanger, in-line sensors, and pumps for circulating the water. The freeze protector is in heat transference contact with the flue of the boiler. The freeze protector, controlled by a temperature sensor, prevents freezing of the water in the solar collector and additionally utilizes waste heat from the flue of the boiler to heat water anytime the boiler is in operation. The boiler is activated, upon the water in the water tank falling below a predetermined temperature. A thermostat controlled fan forces air over the heat exchanger to provide room heating. Check valves are provided for preventing back flow of water from the solar collector. The apparatus may also contain a heat pump having its heat transference coils adjacent to the heat exchanger for full utilization of forced air from the fan.

Abstract: All of the hot flue gases from a furnace are collected and passed through a conduit extending through a closed heat chamber. A plurality of steam coils are disposed about the conduit within the heat chamber at spaced locations along the length of the conduit. Each steam coil is connected to a common water header located within the heat chamber parallel to the conduit. The water header is supplied with water which may be preheated in a suitable water jacket disposed in contact with the outlet end of the conduit outside the heat chamber. Each steam coil has a gradually increasing diameter with the largest diameter end of the coil passing outwardly through an aperture in the heat chamber for delivering steam to be used in any desired manner. A pair of parallel spaced apart pipes extend parallel to the conduit from one end of the heat chamber to the other. One of the pipes is closed at one end and the other pipe is closed at the opposite end.

Abstract: A waste heat recovery system for a heater treater which elevates the overall energy imparted into crude oil from a finite amount of combustion gases. The system includes a vertical heat exchanger supported from the shell of the heater treater. The exchanger has an outer housing within which a plurality of longitudinally arranged tubes are disposed. Untreated crude flows through the interior of the tubes while waste heat from the fire tube is conducted into the lower end portion of the housing so that the outer surface of the tubes contact and extract heat from the flue gases. The flue gases exit through the upper end of the housing. The temperature elevation of the incoming crude is controlled by a damper assembly located at the lower extremity of the exchanger, which admits atmospheric air into the housing.

Abstract: The invention relates to a device for cooling chimney-gases in such plants, where water, heated in a heating boiler, is supplied to heat consumers; e.g. radiators. According to the invention, a condensor-heat exchanger is arranged downstream of the heat consumers, a chimney gas cooler is situated in the chimney gas channel from the heating boiler, whereby said condensor-heat exchanger and said chimney gas cooler are parts of a closed cooling system, containing e.g. freon gas, together with a refrigerating compressor and a throttle.

Abstract: A stack exhaust heat recycling system utilizing the heat content of exhaust gases passing through a smoke stack to the ambient atmosphere. The stack includes an inner shell defining a passage to carry the exhaust gases without restrictive draft. Surrounding this shell in any desired configuration is tubing carrying fluids (liquids, gas or oils). Surrounding the tubing is an intermediate shell, insulation and an outer shell. During the passage of the fluid through the tubing, transfer of heat occurs from the gases to the fluid so that its temperature is elevated for use, e.g., as hot water, thus eliminating or supplementing a hot water heater. Other uses requiring elevation of the temperature of water or gas may be similarly utilized.

Abstract: A heat exchanger operatively arranged, like a sliding drawer in a dresser, to be urged through opposite direction sliding movement to facilitate its positioning at and removal in relation to a heat exchange station within a flue, or the like, of a heating system, with the result that it is readily easy to service and maintain the unit clear of soot and other clogging materials. Since, as noted, the problems associated with clogging are significantly obviated, the heat exchanger, among other advantages, can embody in its construction closely spaced heat exchange fins to greatly enhance the amount of heat extracted from the exiting flue gases.

Abstract: A heat exchanger coil disposed in a furnace chamber or duct to absorb heat from the furnace to increase the temperature of water passing through said coil from a cold water source to a hot water heater or storage tank is disclosed. An additional feature includes a second heat exchanger coil disposed between the cold water source and the furnace heat exchanger within the confines of a building to absorb heat from the ambient surroundings. An insulated coiled storage unit disposed downstream of the furnace heat exchanger to provide a quantity of additional preheated water to the water heater and a spurge tank overheat and overpressure relief unit for the system is also disclosed.

Abstract: The invention concerns heat exchange devices for cooling the wall and the refractory of a blast furnace. Such a device, constituting a cooling box, comprises:a closed enclosure, elongated and having a shape of revolution or substantially of revolution, this enclosure comprising an outer end and an inner end,an axial chamber defining with said enclosure an annular chamber, this axial chamber comprising an outer end and an inner end,a supply orifice for feeding a cooling liquid into the axial chamber through its outer end.

Abstract: A space heater with a heat recovery system in which the exhaust gases from the hot air furnace are passed through a heat exchanger in which a set of water heating coils is disposed. The set of coils is connected to a hot water holding tank which is in turn connected to a bank of heat exchanger coils in the heated air outlet of the furnace. A damper is provided in the exhaust pipe of the furnace and a pipe connects the exhaust pipe on the anterior side of the damper with the heat exchanger, and a pipe connects the chamber with the exhaust pipe on the posterior side of the damper. A pump is provided for circulating the water between the first set of coils and the holding tank, and a fan forces the air form the exhaust pipe through the chamber in the heat exchanger. The pump and fan are controlled by a switch responsive to the operation of the furnace. The holding tank may be used to heat water supplied to a hot water heater of a hot water supply system.

Abstract: A recuperator for recovering heat from hot exhaust gases flowing through a flue comprises inner and outer cylindrical walls coaxially surrounding a portion of the flue to which a plurality of fins are fixed, the fins extending longitudinally of the flue and being grouped such that fins spaced circumferentially around one section of the flue are angularly staggered with respect to fins spaced circumferentially around an adjacent section of the flue, the recuperator being arranged such that cold gas can be passed into, and is preheated as it flows along, an outer annular space between the said walls, the gas passing into an inner annular space containing the fins which cause turbulence and increase the heat-transfer by convection and radiation to the gas, and the heated gas being emitted through an outlet.

Abstract: This invention relates to an improved design associated with the fabrication and construction of a chimney stack capable of conveying hot gases generated in conjunction with industrial endeavors to a height within the atmosphere sufficient to meet current pollution standards, as well as providing a means to dampen stack vibrations plus incorporating a heat extracting system capable of providing a secondary source of heat for utilization outside of the stack confines. In accordance with the invention, there is incorporated within one overall design, a stack capable of conveying hot gases wherein there is provided means for selectively adjusting the opening appearing at the top of said stack, so as to maintain control over the gas velocity as well as plume rise of emitted gases.

Abstract: A waste heat recovery device particularly usable for heating the air traveling through a cold air return duct to a hot air gas heating furnace which includes an exhaust box securable to the wall of the furnace and adapted to receive exhaust gases therein to gather heat in the plenum chamber defined by the exhaust box, the exhaust box also including an exhaust gas outlet to expel gases to the existing heater stack or flue for venting, the plenum chamber including an exhaust coil being in fluid flow communication through a conduit to a return coil which is located within the cold air return, the conduit means being partially filled with a thermal transfer fluid such as water which will boil within the conduit in the exhaust coil means and will condense within the conduit in the return coil means and as such will effect rapid thermal transfer from the heated exhaust waste to the incoming cold air traveling through the cold air return and thereby achieve waste heat recovery.

Abstract: A waste heat recovery system and method for recovering heat from exhaust gases flowing through an exhaust stack or flue from a source of heat. The recovery system includes a heat exchanger located within a bypass assembly that includes a pair of conduits connected to the exhaust stack, and a blower for producing a flow of exhaust gases from the exhaust stack through one of the conduits and the heat exchanger and then back to the exhaust stack through the other of the conduits. The method of the present invention includes the moving of at least a portion of the exhaust gases in the exhaust stack through the bypass assembly and returning such portion back to the exhaust stack.

Abstract: A water heating and forced air heating system that provides potable hot water and that also provides heated air for heating enclosed spaces within buildings, including: a water heater including a water tank filled with water, a burner for heating the water in the tank, and an exhaust flue for removing hot gases generated by the burner; a gas-to-liquid heat exchange unit disposed within the flue; a forced air heater having a casing that defines a chamber, a liquid-to-gas heat exchange unit disposed within the chamber, a gas-to-gas heat exchange unit also disposed within the chamber, and a blower for pulling fresh air into the chamber and blowing it past the heat exchange units to absorb heat; a pump for pumping water through the gas-to-liquid heat exchange unit so that the water becomes heated by the hot gases within the flue; another pump for pumping heated water through the liquid-to-gas heat exchange unit to heat the air flowing within the chamber; and a conduit for connecting the terminal end of the flue t

Abstract: A modular, heat recovery system is provided for use with furnaces, boilers, and the like where otherwise waste exhaust heat is utilized to heat water for home or apartment use. This system includes a plurality of modular pipe loop sections interconnected with one another and mounted in proximity to the stack of the furnace. Each section includes several courses of longitudinally extending U-shaped loops supported on a common perpendicular pipe section at one end and which forms part of a supply line for other sections. Each section is provided with unions and valves by means of which an entire section maybe disconnected for repairs from the other sections without interruption of the operation of the other sections. A drip pan is provided at the lower end of the system to prevent water leaks from dripping onto the furnace.

Abstract: A preheating device for hot water heaters which employs hot gases of combustion from the flue to preheat incoming cold water and to continually preheat water stored in the water tank by natural recirculation. Use of the device provides for increased fuel efficiency because hot combustion gases from the heat source are used for warming of water before venting to the atmosphere, the result being an average increased temperature within the tank so that lesser amounts of fuel are required to reach any desired hot water temperature.

Abstract: A device which is positionable within a flue for recapturing heat from hot gases exiting the flue. The device comprises a pair of tubes which are disposed in parallel relation longitudinally of the flue. The tubes are formed from cylindrical tubes which have been flattened from a circular to a generally oval cross-sectional configuration. A shield is positioned longitudinally between the two tubes for radiating against the tubes, heat which contacts the shield by convection.

Abstract: A heat exchanger is interposed between the exhaust duct of a water boiler and the chimney or flue, and a water conduit, connected to the water return line of the heating system, is disposed within the heat exchanger in heat exchange relationship with the exhaust gases. In this manner, up to 85% of the thermal energy within the exhaust gases is recovered and imparted to the water for pre-heating the same prior to the transmission of the pre-heated water into the boiler for additional heating, or alternatively, directly into the water heating system. A filter assembly is preferably interposed between the heat exchanger and the chimney or flue so as to filter the cooled gases prior to the emission of the same into the atmosphere. As a result, solid particles, and a substantial portion of sulfur dioxide, is removed from the exhaust gases so as to reduce pollution conditions.

Abstract: A chimney, waste-heat, collector includes a plurality of elongated sections, coupled end-to-end and lowerable successively down a chimney. The collector comprises at least one vertical, up-flow, conduit and at least one down-flow conduit within the chimney forming a closed loop system with a pair of horizontal conduits extending out the ash pit opening to a heat storage and dissemination means. The couplings are threaded unions for ready assembly and the sections are preferably of right angular, or rectangular cross section and of thin wall stainless steel. A pump circulates liquid around the loop when the furnace is operated.

Abstract: A water heater capable of utilizing as one of its heat sources hot exhaust gases emitted from at least one other heat source such as a furnace fueled by a natural resource fuel such as gas or oil, and capable of utilizing as another of its heat sources heat emitted from a fluid heated by solar energy. The water heater comprises a central flue having a heat conductive wall, one end of the said flue having a thimble member secureable to an exhaust pipe carrying hot exhaust gases from a heat source fueled by a natural resource fuel, and the other end of said flue secureable to a chimney leading to the atmosphere. Disposed within the flue is a turbulator means which disperses entering hot exhaust gases along the surface of the flue wall.

Abstract: A fireplace heat exchange system is disclosed which is connectable to an existing forced air heating system of a building. The heat exchange unit includes a housing or enclosure within which is disposed a firebox. The enclosure and the firebox define a heat exchange space. The firebox includes a front opening which is closed by doors. A plenum is positioned on top of the firebox for collecting combustion gases. A plurality of heat exchange fins are secured to the exterior of the firebox within the heat exchange space to channel the incoming air entering the housing around and over the firebox and to increase the efficiency and rate of heat exchange. An air control device is positioned adjacent the front of the firebox to control the amount of combustion air entering the firebox. A chimney connects to the plenum and a chimney damper limits the combustion gas flowing out the chimney.

Abstract: An automatically controlled residential heating system based on the heat from a fireplace comprising the normal fireplace, hearth, combustion zone, flue, and damper; the flue being divided into two parallel flue passages one of which is unobstructed and the other of which contains a heat exchanger adapted to absorb the heat from the flue gases into a fluid passing through the heat exchanger and then into space heating elements in the residence; the system including automatic devices for sensing the temperature in the heat exchanger and the temperature in the residential spaces to be heated, an automatic control to act upon the temperature sensing means and to move a diverter which serves to pass the flue gases into either or both of the parallel flue passages in any desired proportion, an automatic relief valve means for relieving excessive temperature build-up in the heat exchanger, and an automatic extinguishing device for extinguishing the burning material in the fireplace if the means for sensing the temp

Abstract: A heat transfer system for use in supplementing the operation of the heating/cooling system of a building and its hot water heating system includes a heat exchanger in the flue of the furnace as well as a heat exchanger in the fan chamber. A first liquid circulation loop couples the heat exchangers for transferring heat from the flue exchanger to the air moved through the fan chamber heat exchanger. A second liquid circulation loop includes the flue exchanger and the building hot water heater for supplementing the heating of water therein. In the summer months during the cooling mode of the systems operation, cold water employed, for example, for lawn sprinkling is passed through the fan chamber heat exchanger for cooling and dehumidifying air circulated in the building. A valve control system is employed to automatically control the flow path of fluid in the system as a function of detected temperatures.

Abstract: A fireplace heating and cooling system is disclosed which heats air in a forced air heating system and heats water for a circulating hot water heating system or for hot tap water when combustion occurs in the fireplace and alternately will cool the air in a central, forced air system by circulating water cooled by a heat sink, through heat exchangers. A water reservoir is mounted on top of a fireplace firebox, having a central passage formed therethrough communicating with the throat of the firebox for absorbing heat from the combustion gases to heat water stored in the reservoir. A valve means selectively connects the water reservoir to a pressurized water supply, with an outlet to a circulating hot water heating system or to hot water taps. An air plenum is formed around the reservoir for circulating air from the ambient, across the reservoir to transfer heat between the water and the air.