Abstract: A method and apparatus for increasing the circulating airflow of induced-draft, gas-fired multi-stage furnaces without creating conditions that result in cold spot corrosion therein. Control circuitry is provided to selectably increase the circulating airflow of the furnace during low stage operation. The control circuitry is arranged so that increases in the magnitude of the circulating airflow of the furnace are accompanied by predetermined increases in the magnitude of the combustion airflow of the furnace. The magnitudes of the circulating and combustion airflows are so related to one another that the temperature at the output of the heat exchanger is maintained at a value which is approximately constant, and which is high enough to assure that water cannot condense thereon. The control circuitry may include a relay or relay-like device that is connected to prevent the high stage solenoid of the gas valve from becoming actuated during low stage operation.

Abstract: A portable forced air heater includes a one-piece unichassis structure which forms the base and the outer housing of the heater. The outer housing defines an elongated passage having a front end and a back end and which receives a burner assembly. The burner assembly is spaced from the outer housing such that cooling air flows between the combustion chamber of the burner assembly and the outer housing. The burner assembly itself includes the elongated combustion chamber which is shorter than the air passage defined by the outer shell and includes a rear head member which is snapped into place in the inlet end of the combustion chamber. Self-aligning mounting tabs and brackets are formed in both the unichassis and the combustion chamber to significantly reduce the number of parts and to simplify construction.

Abstract: A burner system for a furnace (10) includes an in-shot burner (20) having an axially elongated tubular nozzle (40) having an inlet end (42), an outlet end (44) and a venturi transition section (46) therebetween. At least a portion of a catalyst body (50) is disposed within the outlet end (44) of the burner (40). The catalyst body (50) supports a partial oxidization catalyst operative to catalyze the fuel in the primary air/fuel mixture to intermediate combustion species, including hydrogen and carbon monoxide, thereby reducing emissions such as nitrogen oxides.

Abstract: An enclosure surrounding the burner of a furnace, including a top panel, a rear panel, a bottom panel, a front panel, and first and second side panels. An air inlet is provided in one of the panels. A baffle is provided within the enclosure and extends between two opposed panels, each of the opposed panels adjacent the panel having the inlet. A chamber is partly defined by the baffle, the inlet opening into the chamber. The chamber is provided with a vent through which the inlet is in fluid communication with the burner.

Abstract: A multi-category gaseous fuel-fired heating apparatus having a combustion chamber, a mixing chamber in fluid communication with the combustion chamber, and an induced draft blower in fluid communication with the mixing chamber whereby combustion air is drawn into the combustion chamber for combustion of the gaseous fuel and the flue gases are drawn from the combustion chamber through the mixing chamber and exhausted into either a high temperature flue gas vent or a low temperature flue gas vent. The mixing chamber includes a dilution air inlet which, in a high temperature vent mode of operation of the heating apparatus is sealed off by an orifice plate disposed between the mixing chamber and the induced draft blower, and in a low temperature vent mode, the dilution air inlet is open and a larger blower inlet orifice is used.

Abstract: A clamshell heat exchanger (10) is provided for use in a heating apparatus including a burner for producing hot combustion gas. The heat exchanger (10) defines a multi-pass flow passage (11) for the combustion gas and includes a first plate member (30) and a second plate member (32). The first plate member (30) has a first series of parallel ridges (36) and valleys (38a-b), with at least one of the valleys (38a) being deeper than other of the valleys (38b). The second plate member (32) faces the first plate member (30) and includes a second series of ridges (36) and valleys (38a-b) that are parallel to the first series of ridges (36) and valleys (38a-b), with at least one of the valleys (38a) of the second series being deeper than other of the valleys (38b) of the second series. A first pass (14, 16) of the multi-pass flow passage (11) is defined by a number N1 of the ridges (36) and valleys (38a-b) of the first and second series.

Abstract: A burner has a burner tube and a nozzle holder mounted in one end of the burner tube. An igniter is positioned within the nozzle holder and acts to ignite any of the multi-liquid fuels which may be used with the burner. A nozzle emits atomized liquid fuel under the venturi effect of the nozzle with compressed air being supplied to the nozzle. Primary air holes extend circumferentially around the nozzle holder to admit air radially which passes directly to the burner tube. Secondary air holes extend around the inside circumference of the burner tube on the secondary air injection plate and admit air axially to the burner tube.

Abstract: A low NOx burner having a burner body, to which an electric fan for supplying air for combustion is connected and which includes an exhaust gas recirculation passage for supplying combustion gas from the burner body to air for combustion, the low NOx burner including an exclusive exhaust-gas recirculation fan provided for the exhaust gas recirculation passage and arranged to forcibly recirculate exhaust gas, and a bypass passage formed between the exhaust gas recirculation passage and a passage for air for combustion formed in the burner body.

Abstract: A heat exchange device for harnessing heat from an exhaust vent is provided including a furnace having a main inlet for receiving cooled air suctioned from a living area, a heating mechanism for heating the cooled air suctioned from the living area, a main outlet for delivering air to the living area which is heated by the heating mechanism, and an exhaust vent coupled to the furnace for expelling air associated with the generation of heat by the heat mechanism with such expelled air not being fit for channeling to the living air via the outlet. Next provided is a housing which divides the exhaust vent into a lower portion and an upper portion. The housing has an auxiliary inlet in communication with the living area for receiving the cooled air therefrom and an auxiliary outlet in communication with the living area for expelling air thereto. Lastly, a heat transfer mechanism includes a pipe formed in the shape of a helix.

Abstract: A secondary heat exchanger suitable for use in a condensing furnace which is in the form of a bank of a plurality of metal tubes which are positioned in a plurality of stacked rows. The tubes are interconnected to form a continuous fluid flow path and have a uniform adherent corrosion resistant polymeric internal surface. The tubes further contain a longitudinal seam which is formed by crimping the edges of the tube together to provide for the compression of two polymer surfaces together thereby forming a seal capable of maintaining its integrity at conventional design pressures.

Abstract: A new variable burner orifice furnace manifold for reducing the amount of heating fuel used without reducing the heating ability of the furnace. The inventive device includes a manifold pipe with a plurality of spaced apart gas exit openings between its open supply end and its closed end. The gas exit openings are inserted into the burner assembly of a furnace and the supply end is attached to an external heating fuel supply. A valve permitting selective opening and closing is included on the manifold pipe. The valve is positioned on the manifold pipe so that no more than half the total number of gas exit openings are positioned between the valve and the manifold pipe closed end. When the valve is closed, gas flow through the gas exit openings between the valve and the closed end is shut off while gas flow through the gas exit openings between the valve and the open supply end is unaffected.

Abstract: An improved high-efficiency furnace for use with manufactured housing has a modular heat exchanger assembly having a drum and a plurality of serpentine shaped tubes. A burner extends at least partially into the drum portion of the heat exchanger which acts as a combustion chamber. Hot combustion gases flow upwardly within the drum and enter the tubes heating the drum and tubes. Room air is drawn into the furnace by a circulating blower and blown against the plurality of tubes. The room air is then directed to flow around the drum portion of the heat exchanger where it is further heated before being discharged into the space being heated. The burner includes an inwardly tilted target plate having a plurality of fingers for facilitating the formation of a stable ball of flame within the drum.

Abstract: A furnace having improved heat exchanger, which is particularly suitable for use in a positive pressure, direct-vented hot air furnace. The heat exchanger has a split housing construction allowing the heat exchanger to be partible into halves. Parting the heat exchanger housing of the present invention permits access to the ceramic combustion chamber disposed therein, facilitating periodic repair and replacement. The partible portions of the present heat exchanger housing are connectable using one of several available connection means, including bolted mating flanges, encircling clamps, and twisting quick-locking means. The connection between the partible portions is gasketed to provide a positive pressure seal of the connection, impeding leakage of pressurized combustion gases from within the heat exchanger to the occupied air.

Abstract: A heater for heating a stream of air has a burner assembly to heat the stream as it flows along a flow path and a primary heat assembly positioned in the flow path and coupled to the burner assembly for conducting gaseous combustion products. The primary heat exchange assembly has an array of U-shaped heat exchange tubes for conducting hot combustion products generated by the burner assembly to an array of second U-shaped heat exchange tubes for combustion products discharged from the first heat exchange tubes, the second tube having a smaller diameter than the first and being positioned in the space defined by the array of first U-shaped heat exchange tubes. Combustion products leaving the primary heat exchange assembly are passed through a secondary heat exchange assembly before being exhausted.

Abstract: A method and apparatus for reducing emissions in combustion products. Fuel and primary oxidant are introduced into a burner tube and discharged as a fuel/oxidant mixture, preferably fuel-rich, into a primary combustion chamber. The combustion flame entrains, through a peripheral gap between the burner tube and a wall of a first housing, a first portion of secondary oxidant in the primary combustion chamber. The combustion flame is then directed, preferably through a swaged orifice, into a secondary combustion chamber. Within the secondary combustion chamber, the combustion flame entrains a second portion of secondary oxidant and then combustion products are discharged through an exhaust tube.

Abstract: An improved furnace is provided which can be field modified to change the pressure drop across the inducer. The pressure drop is modified to accommodate vertical or horizontal venting and adequately lined and inadequately lined chimneys. A first rate of flow of combustion byproducts into the vent system is used when the chimney is adequately lined and a second relatively higher rate of flow is used when the chimney is inadequately lined. The rate of flow is changed by inserting or removing an obstruction in the flow of combustion byproducts. The obstruction could be a tab or choke placed at the inducer outlet or a similar device in the inducer inlet. When the tab is in place the flow of combustion byproducts is reduced. When the tab is removed, the flow rate increases. Alternatively, the inducer inlet could be adjusted to increase or decrease the amount of air flow through the inducer.

Abstract: A mixing/quenching device is in the form of a perforate metal sheet or screen secured at the downstream end of a belled orifice with the perforations defining a plurality of flow paths. The dividing and combining of the flow is passing through the flow paths provides turbulence such that thermal NO.sub.x is reduced.

Abstract: Required blower power in an induced draft combustion system is reduced by recovering pressure from dynamic energy of flow of combustion products. To this end, the outlet duct is diverged gradually, such as an included angle of less than fifteen degrees, and preferably at an angle of substantially seven degrees. Divergence of the outlet duct may be expressed in polar coordinates having a polar axis, overlapping radius vectors and a variable polar angle of such overlapping radius vectors relative to the polar axis. A difference between such overlapping radius vectors is increased in a direction of flow of the combustion products and the outlet duct is structured with cross-sections increasing incrementally in terms of the increasing difference between the overlapping radius vectors. Condensate may be drained from a combustion product by providing the duct with a lateral offset having a bottom extending at an angle to the earth's field of gravity.

Abstract: A gas appliance, flue assembly, or vent adapter including an adjustable flow regulator which regulates the proportions and volume of dilution air and combustion products into the vent is disclosed. The flow regulator can be adjusted to allow a given appliance to exhaust vent gases through a range of different venting systems constructed from a wide range of materials. The appliance installer may adjust the appliance vent gases for a particular pre-existing or installed vent. The flow regulator also provides flow resistance which helps prevent backdrafting and the free escape of dilution air (which may be heated room air in some instances) through the vent to the outside atmosphere.

Abstract: An indirect-fired climate control apparatus for modifying certain aspects or properties of air flowing through a controlled environment, with the apparatus employing a rotary air-energy exchange device with means for bilaterally introducing and extracting energy from primary and secondary air flows. The apparatus includes a feature for recycling portions of the air flow on the primary side so as to more efficiently utilize the energy resource, and deliver this energy to the secondary side. The apparatus is suited for treating air flow with thermal energy for modifying its temperature, as well as energy for controlling the moisture content of the air flow on the secondary side.

Abstract: An apparatus for detecting a head wind in a gas boiler and method is disclosed which is capable of the magnitude of variation of voltage corresponding to the R.P.M. of an exhaust fan and the combustion state of flame. A microcomputer in the gas boiler detects the R.P.M of exhaust fan and voltage applied to the exhaust fan when the R.P.M exceeds a normal limit. The detected voltage is compared with a reference voltage. If the compared result exceeds a predetermined value, to sense the combustion state of flame an infrared rays sensor is used. When the head wind is introduced into an exhaust conduit, the red wavelength is sensed at flame due to incomplete combustion. Accordingly, in case that the magnitude of variation of voltage exceeds a predetermined value and the red wavelength is sensed, microcomputer can detect the head wind.

Abstract: A multiple inshot-type gas burner structure is formed from a pair of facing, intersecured stamper sheet metal plates. A spaced plurality of parallel, rectangularly cross-sectioned burner bodies are defined by facing triangular indentation pairs in the plates and have, at front outlet end portions thereof, side indentations which serve to mix air and gaseous fuel received at rear end portions of the burner bodies, and to divert a portion of the fuel/air mixture into crossover channels intercommunicating front interior portions of the burner bodies. The crossover channels have central arcuate closed portions that cooperate with progressively sized standoff dimples extending between opposite wall portions of the channels to provide an even crossover flame pattern along the outlet slot section of each channel.

Abstract: A control system for regulating a flow rate of a heat transfer fluid in a heat transfer system, the heat transfer system having a heat transfer fluid flow path, flow control device for creating flow along the path, a fuel source for providing a combustible fuel to the path, an air source for providing combustion air to the path, and an assembly for combusting the fuel and air, the control system comprising a sensor for sensing a measured flow value at the air source, a controller for storing an optimum flow value at the air source and for storing a range of operating control values for the flow control device, the operating control values corresponding to the optimum flow value, a system for calculating a deviation between the measured flow value and the optimum flow value, and a system for varying the operation of the flow control means in accordance with the deviation.

Abstract: A heating apparatus for delivering heated air to an enclosure comprising a casing with at least two compartments separated by a panel. A burner with an arcuate profile is located within a first compartment of the casing for burning a combustible fuel-air mixture delivered thereto and producing products of combustion. A heat exchanger is located within a second compartment of the casing and has an opposed inlet and outlet. The inlet is in fluid communication with the burner through an aperture in the panel. The heat exchanger receives the products of combustion. A blower is located within the casing for directing a flow of air across the heat exchanger into the enclosure. Through the heat exchanger heat is transferred from the products of combustion to the air. An exhaust system is in fluid communication with the outlet and includes a vent for exhausting the products of combustion from the casing. The vent is contained within the casing.

Abstract: A heat exchanger manifold (44) is provided which includes a plurality of manifold inlet openings (58) including sealant means such as grommet means (62) which receive the tube outlets (40c) of the condensing section (34) of a heat exchanger (28). The heat exchanger manifold (44) is made of a corrosion-resistant material such as a polymer such as one sold under the trademark LEXAN.TM. and the grommets (62) are preferably made of a resilient, corrosionresistant polymer such as rubber, e.g., a nitrile rubber. The condensing tubes (38a, 38b, 38c) are slanted to facilitate drainage of the condensate into the heat exchanger manifold (44) and a flue gas outlet (64) and a condensate drain (49) are provided to discharge, respectively, flue gas and condensate from the heat exchanger manifold (44). The condensing tubes (38a, 38b, 38c) are connected to the primary heating section (30) of the heat exchanger (28) through swaged joints (37).

Abstract: A furnace is adapted for operation in downflow, left horizontal flow and right horizontal flow positions. The furnace includes plural burners, a two-stage heat exchanger, a header box at the heat exchanger outlet for collecting products of combustion from the heat exchanger, and an inducer for inducing a flow of products of combustion through the heat exchanger. A condensate drain and trap are also provided for draining condensation from the header box and from an exhaust vent through which products of combustion are exhausted from the furnace. In accordance with one feature of the invention, a manifold is located inside the header box to divide the header box into first and second chambers. A pressure sensor senses differential fluid pressure between the first and second chambers for detecting a blocked condensate drain condition.

Abstract: A modulating, forced draft, fuel-fired air heating furnace is provided with a two-speed draft inducer fan, and a fuel valve which is fully modulatable between a maximum firing rate and a low firing rate of approximately forty percent thereof. Incorporated into the furnace control system are normally closed low and high fire pressure-electric switches which sense and are sequentially closed by increasingly negative pressure in the draft inducer fan. Upon a call for heat from a thermostat located in the conditioned space served by the furnace, the draft inducer fan is energized at its high speed setting, and a signal is sent to the fuel valve to set it at its full firing rate flow when opened by an ignition switch portion of the control system. The control system functions to open the fuel valve at this maximum flow setting, and permit light-off of the burner, only if (1) both of the low and high fire pressure-electric switches are closed, and (2) the draft inducer fan is operating at its high speed setting.

Abstract: A fuel-fired air heating furnace is provided with NOx reduction apparatus associated with a plurality of combustor tubes forming a portion of the furnace heat exchanger section. Inshot-type fuel burners are spaced apart from and face the open inlet ends of horizontal combustion sections of the combustor tubes. The NOx reduction apparatus includes a plurality of NOx reduction members formed from a metal rod material, and a mounting plate having a row of spaced apart pairs of mounting holes therein. Each NOx reduction member has an elongated, generally U-shaped configuration, with a closed inner end, an open outer end, and a spaced pair of corrugated leg portions extending between such inner and outer ends.

Abstract: A condensate trap assembly. The assembly comprises a housing having first and second condensate inlets where the first condensate inlet is sized to pass more condensate than the second condensate inlet. The housing has an ambient air inlet providing access to an ambient air chamber within the housing, a first condensate chamber open to the first condensate inlet, and a second condensate chamber open to the second condensate inlet. The first condensate chamber, the second condensate chamber, and the ambient air chamber are open to each other and the first condensate chamber includes airflow restrictors to retard the volume of airflow through the first chamber.

Abstract: A fuel-fired, forced air, draft induced heating furnace is provided with NOx reduction apparatus associated with a plurality of combustor tubes forming a portion of its heat exchanger structure. In-shot type fuel burners are spaced apart from and face the open inlet ends of horizontal combustion sections of the combustor tubes. The NOx reduction apparatus includes a plurality of metal mesh tubes having diameters substantially less than the internal diameters of the combustion tubes. Each metal mesh tube is coaxially anchored to and telescopingly over the outlet end of one of the burners and extends therefrom coaxially into the associated combustion tube.

Abstract: A high efficiency furnace having a heat exchanger and an inducer fan housing attached to the flue gases exit of the heat exchanger to draw flue gases out of the exchanger and force the gases out of the furnace under pressure through a venting system. A condensate return channel is provided for directing condensate developed in the vent system back into the inducer housing where it its removed from the furnace by a drain.

Abstract: A control system for regulating a flow rate of a heat transfer fluid in a heat transfer system, the heat transfer system having a heat transfer fluid flow path, flow control device for creating flow along the path, a fuel source for providing a combustible fuel to the path, an air source for providing combustion air to the path, and an assembly for combusting the fuel and air, the control system comprising a sensor for sensing a measured flow value at the air source, a controller for storing an optimum flow value at the air source and for storing a range of operating control values for the flow control device, the operating control values corresponding to the optimum flow value, a system for calculating a deviation between the measured flow value and the optimum flow value, and a system for varying the operation of the flow control means in accordance with deviation.

Abstract: A control system for a fluid-fuel burner, such as a furnace for an HVAC system. The furnace has a variable flow of fuel into the burner. In addition, the circulating air blower is also variable. The furnace heat exchanger plenum is maintained at a substantially constant temperature, as a means for providing substantially constant temperature air to the spaces to be heated.

Abstract: A multi-poise furnace that is capable of operating in either a vertical or horizontal orientation and having a primary heat exchanger coupled to a condensing heat exchanger, apparatus for collecting and draining condensate leaving the condensing heat exchanger.

Abstract: A heat exchanger assembly comprises a partition or mounting plate with an aperture therethrough and a heat exchanger wall with an opening therethrough where the plate and wall are assembled together with the plate aperture and wall opening adjoined and sealed by a sponge pad in accordance with the method of the invention.

Abstract: Apparatus and process for condensing furnace hot air humidification using aqueous condensate from flue gases generated by the thermal exchanger in the furnace as the primary aqueous input to the evaporator of a humidifier which, preferably, may be integral with the furnace or which may be retrofitted in the field. Use of the system of this invention provides long term reliability and low maintenance to furnace humidification systems.

Abstract: A high efficiency hot air furnace transfers substantially all of the combustion heat of a clean fuel gas fire to a stream of cool recirculating air by two heat exchangers both of which are mounted in a common plenum through which cool air is recirculated by means of a blower. It differs from the conventional high efficiency furnace in that the secondary heat exchanger is a porous movable heat sink which is alternately exposed to a stream of hot combustion gas and a part of the cool air stream from the recirculating air blower.

Abstract: A fuel fired, forced air, draft induced heating furnace is provided with NOx reduction apparatus associated with a plurality of combustor tubes forming a portion of its heat exchanger structure. In-shot type fuel burners are spaced apart from and face the open inlet ends of horizontal combustion sections of the combustor tubes. The NOx reduction apparatus includes a plurality of insert members received in inlet end portions of the combustor tubes. Each insert member is formed from a single sheet of metal mesh material and has a hollow, open-ended body portion coaxially received in its associated combustor tube and spaced laterally inwardly from its interior side surface, and a circumferentially spaced plurality of integral, laterally outwardly projecting support rib portions that slidably engage the interior side surface of the combustor tube, thereby automatically maintaining the insert member in a coaxial relationship with the combustor tube regardless of the positional orientation of the tube.

Abstract: A pocket heat exchanger comprises an elongated combustion chamber that defines a plane passing through the combustion chamber longitudinal axis. A two-pass, three-pass, or four-pass duct system is arranged symmetrically about the plane to conduct hot products of combustion produced in the combustion chamber in parallel paths to a flue. The pocket heat exchanger is installable as a modular unit into the pocket of a recirculatory fluid system. The symmetrical design of the pocket heat exchanger assures that a stream of recirculating gas flowing past the pocket heat exchanger is heated to have a uniform temperature across its cross section. A shroud partially surrounding the combustion chamber and the duct system aids in directing the recirculating gas to thoroughly scrub the combustion chamber for maximum heat transfer to and temperature uniformity of the stream of gas. The flue for the products of combustion may pass through the stream of recirculating gas, or it may pass outside the stream of the gas.

Abstract: A pressurized space heater for burning gaseous fuel has as its main component a generally conical burner tube that receives at its narrow end a combustible mixture of fuel and primary air. Complete combustion in the tube is enhanced by two sets of holes disposed along the tube for admitting secondary air. The location, number and sizes of the holes are so chosen as to ensure complete combustion and to avoid the production of noxious substances.

Abstract: A self-powered forced or induced draft water heater is provided including a tank adapted for storing hot water, a sealed combustion chamber, a powered burner, a thermoelectric module, and a through-chamber heat sink having a base portion and a pin portion. The combustion chamber has a common wall with the tank at a lower zone of the tank. The powered natural gas burner has a blower which delivers air to the burner through an inlet duct and forces combustion products out a flue. The thermoelectric module generates operating power for the burner blower. The thermoelectric module has a hot side in thermal communication with a combustion zone of the burner and a cold side attached to the heat sink base portion. The pin portion of the heat sink is conically shaped and extends through an opening in the common wall to the interior of the tank. The base portion of the heat sink is removably attached to the common wall and is provided with an o-ring or other means to seal the wall opening.

Abstract: A methods and apparatus for exhausting flue products and removing condensate from a combustion of air/gas mixtures provide a condensate collecting pan for flue products. That pan is provided with an inlet for flue products and condensate, and with an outlet for flue products spaced from that inlet. That inlet is provided with a larger cross-section for flue product and condensate flow than the outlet. A space is provided in the pan for a flow of flue products from the inlet at a substantially even velocity across the larger cross-section of the inlet to the smaller cross-section outlet. Condensate collecting in that space is removed from the pan.

Abstract: A device for inhibiting NOx production is disposed in a gas furnace combustion chamber. The device includes a baffle member for dividing the combustion chamber into first and second regions. A fuel-rich mixture of gas and primary combustion air is ignited by an inshot burner and the flame is drawn into the combustion chamber by an induced draft blower along with secondary combustion air. The combustion chamber is configured such that in the first region (i.e., upstream of the baffle member) turbulent mixing of the secondary combustion air with the flame is inhibited to maintain a relatively gas-rich flame. The baffle member channels the flame and secondary combustion air into a convergent flow path and the passage of the flame and secondary combustion air over the baffle member creates turbulence, which enhances mixing between the flame and secondary combustion air in the second region of the combustion chamber (i.e., downstream of the baffle member).

Abstract: A unitary furnace through which air is circulated for heating purposes is disclosed. A blower forces air through a number of heat exchange tubes horizontally positioned within the combustion chamber for space heating purposes. Another blower is provided for the delivery of air to the burning material disposed upon a fuel support frame within the combustion chamber through an air distribution manifold. The manifold is fitted within the combustion chamber and has a number of air discharge openings positioned above and below the fuel support frame. These openings are oriented and arranged to direct the air passing therethrough generally inwardly toward the fuel on the fuel support frame. An electrical circuit including temperature sensors is provided for regulating air flow from each of the two blowers. One sensor is positioned in the furnace flue outlet and the other sensor is positioned exteriorly of the furnace in the space to be heated.

Abstract: A heat exchanger comprises a clam shell having a first passage, a second passage and a third passage connected sequentially in a plane. A hot collector box made from metal, for example, aluminized steel, in connected to the third passage. A secondary heat exchanger coil is operatively connected to the hot collector box. A second collector box or cold collector box made from plastic is connected to the outlet of the secondary heat exchanger coil. Condensate from the flue and condensate from the cold collector box may be discharged in a common line from the furnace. The clam shell is constructed and arranged to remove about 90%-95% of the energy from the flue products flowing therethrough. The heat exchanger is disposed in a passage between the inlet and the outlet in the housing of a furnace. Air is forced over the heat exchanger, which is disposed in the passage, by a blower in the housing.

Abstract: A gas burner system in which a turbulator disk is arranged between a burner and an opening in a combustion chamber aligned with the burner. The turbulator disk defines a central port and a plurality of peripheral voids adjacent to the central port. A burner flame, produced by ignition of a gas-primary air mixture, together with a quantity of secondary air, may be directed through the central port of the turbulator disk into the combustion chamber. A additional quantity of secondary air may be directed through the voids into the combustion chamber for combustion of the uncombusted gas from the gas-primary air mixture.

Abstract: A secondary condensing heat exchanger for use in a multi-poised furnace that includes multiple single pass heat transfer stages. Each stage includes a housing having an entrance at one end and a pair of outlets at the other end. The walls of the housing are arranged to conduct condensate formed in the housing through one or both outlets, depending on the orientation of the furnace. Lateral flow restrictors are mounted in the housing to direct flue gas products entering the housing back and forth across the housing.

Abstract: An upflow/downflow high efficiency furnace includes a means for mounting a secondary heat exchanger by use of a hinge member, which permits the furnace to be installed in either an upflow or downflow mode of operation, without any modification to the furnace as manufactured.

Abstract: A fuel burning furnace includes a number of energy efficient features. The furnace includes a heat exchanger in which combustion air is preheated by hot discharge gases. Diverters are provided in the heat exchanger to continually urge hot combustion gases toward the interior portions of the heat exchanger to improve its heat transfer characteristics. The furnace incorporates a number of features to determine malfunction and indicate inefficient operation. A humidification control system for the humidification or dehumidification of circulated air also is provided. The furnace also includes a blower motor system which compensates for loss of tension in driving belts and makes correction for blower speed in response to temperature variations.

Abstract: An uninterruptible gas-fired forced hot air furnace utilizes a thermoelectric generator in the path of the hot combusted gas to a heat exchanger. The combusted gas (combustion products) flows through the pipes of the heat exchanger to an exhaust which may lead to the chimney,or direct vent, in the building in which the furnace is located. The thermoelectric generator is also in the path of the forced cold air which also goes to the heat exchanger. The cold air thus picks up heat in the process of cooling the cold junctions of the thermoelectric generator and picks up more heat in the heat exchanger from the combustion products before being ducted into the heating system. The thermoelectric generator cold junctions may be air-cooled by fins connected thereto through which the stream of air from the blower passes or the cold junctions may be cooled by liquid which is circulated through a liquid-to-air heat exchanger.