Abstract: A heat recovery system (including associated methods, apparatus and controls for implementing such a system) integrated in a hot water heating system that is combinable with an air conditioning loop containing hot gas wherein the hot water system selectively utilizes heat recovered from the hot gas to produce and store hot water at a preselected temperature level requiring the use of only a single water storage tank. According to one aspect of the invention, hot gas is taken from the air conditioning loop and placed directly into a heat exchanger coil immersed in the water storage tank for selective use therein to produce hot water.

Abstract: A fluid heater for a non-mixing blower combustion system comprises a flame holder including an igniter positioned at the region of highest gas-air concentration and an insert positioned in the lower portion of the flame holder to create a gas-air distribution along the length of the flame holder favorable to reliable ignition. The gas is ignited without creating an audible sound by assuring early ignition of the greatest concentration of the air fuel mixture. Also, the temperature of the exhaust gas from the heater is sufficiently high to prevent corrosive condensates from forming in the exhaust pipes. To prevent flashbacks in the air supply line, which could destroy the blower and associated duct work, the gas pressure is constantly monitored. If air flow does not occur, the gas supply line valve is closed to avoid flow of unburned gas outside the combustion chamber.

Abstract: Combustion apparatus (10) includes a combustion chamber (12, 212), a cover (24, 208) covering an end wall (14, 210) of the combustion chamber and defining a buffer space (26, 206) therebetween, and a blower (32, 202) external to the cover and supplying air to the buffer space and pressurizing the buffer space to a higher pressure than the combustion chamber such that leakage at penetrations (46) and/or interface (334, 336) flows from the buffer space into the combustion chamber, rather than the reverse, eliminating the need for leak-tight seals, and instead permitting leakage in a desired direction. In one embodiment, a first conduit (58) supplies air along a path (34) from the blower to the mixer and burner assembly without passing through the buffer space, and a second conduit (60) independently supplies air from the blower to the buffer space. A pressure dropping orifice (36) is provided between the blower and the mixer and burner assembly.

Abstract: In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil surrounding the primary. Gases flow radially through the primary coil, axially along a baffle and then axially through the secondary coil at an increased velocity. The gas/air mixture is burned in a burner within the primary heat exchanger and the gas product are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.

Abstract: A high efficiency gas fired residential water heater includes an insulated, plastic-lined storage tank. The water in the tank is heated by an external heat exchanger which defines a water-walled combustion chamber. The fuel gas and combustion air burned in the chamber are premixed to a near stoichiometric mixture without the use of a blower. Under the force of line pressure or less, the fuel gas is accelerated into an aspirator/mixer which premixes an amount of air sufficient for complete combustion of the fuel gas. The water-walled combustion chamber is particularly suited for substantial recovery of the heat of a pilot flame. The pilot products of combustion heat water at the upper end of the combustion chamber without causing significant convective flow throughout the heat exchanger.

Abstract: In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil positioned below the primary. Gases flow radially through the primary coil and then axially through the secondary coil at an increased velocity. The gases are then used to pre-heat a gas/air mixture in a third heat exchanger within the secondary heat exchanger. The pre-heated gas/air mixture is burned in a burner within the primary heat exchanger and the gas products are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.

Abstract: A high efficiency gas fired residential water heater includes an insulated, plastic-lined storage tank. The water in the tank is heated by an external heat exchanger which defines a water-walled combustion chamber. The fuel gas and combustion air burned in the chamber are premixed to a near stoichiometric mixture without the use of a blower. Under the force of line pressure or less, the fuel gas is accelerated into an aspirator/mixer which premixes an amount of air sufficient for complete combustion of the fuel gas. The water-walled combustion chamber is particularly suited for substantial recovery of the heat of a pilot flame. The pilot products of combustion heat water at the upper end of the combustion chamber without causing significant convective flow throughout the heat exchanger.

Abstract: Combustion apparatus (10) includes a combustion chamber (12, 212), a cover (24, 208) covering an end wall (14, 210) of the combustion chamber and defining a buffer space (26, 206) therebetween, and a blower (32, 202) external to the cover and supplying air to the buffer space and pressurizing the buffer space to a higher pressure than the combustion chamber such that leakage at penetrations (46) and/or interface (334, 336) flows from the buffer space into the combustion chamber, rather than the reverse, eliminating the need for leak-tight seals, and instead permitting leakage in a desired direction. In one embodiment, a first conduit (58) supplies air along a path (34) from the blower to the mixer and burner assembly without passing through the buffer space, and a second conduit (60) independently supplies air from the blower to the buffer space. A pressure dropping orifice (36) is provided between the blower and the mixer and burner assembly.

Abstract: In a water heating system, vapor in the products of combustion gases is condensed in a secondary heat exchanger positioned in a housing with the primary heat exchanger and combustion chamber. The two heat exchangers are coaxial coils with the secondary coil positioned below the primary. Gases flow radially through the primary coil and then axially through the secondary coil at an increased velocity. The gases are then used to pre-heat a gas/air mixture in a third heat exchanger within the secondary heat exchanger. The pre-heated gas/air mixture is burned in a burner within the primary heat exchanger and the gas products are drawn through the exchangers by a blower. A water storage tank is designed to enhance stratification of hot water over cooler water. The cooler water is used to condense vapor in the secondary heat exchanger.