Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and multi-slab heat exchangers are provided that include fluid connections for transmitting fluid between groups of tubes. The fluid connections may include generally tubular members fluidly connected to manifold sections. The fluid connections also may include partitioned manifolds containing tubes of different heights. Multichannel tubes are also provided that include a bent section configured to locate a flow path near a leading edge of a tube within one section and near a trailing edge of the tube within another section.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include manifold configurations designed to promote mixing of vapor phase and liquid phase refrigerant. The manifolds contain flow mixers such as a helical tape, sectioned volumes, and partitions containing apertures. The flow mixers direct the flow of refrigerant within the manifold to promote a more homogenous distribution of fluid within the multichannel tubes.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and multi-slab heat exchangers are provided that include fluid connections for transmitting fluid between groups of tubes. The fluid connections may include generally tubular members fluidly connected to manifold sections. The fluid connections also may include partitioned manifolds containing tubes of different heights. Multichannel tubes are also provided that include a bent section configured to locate a flow path near a leading edge of a tube within one section and near a trailing edge of the tube within another section.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include manifold configurations designed to promote mixing of vapor phase and liquid phase refrigerant. The manifolds contain flow mixers such as a helical tape, sectioned volumes, and partitions containing apertures. The flow mixers direct the flow of refrigerant within the manifold to promote a more homogenous distribution of fluid within the multichannel tubes.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include tube and manifold configurations designed to promote separation of vapor phase and liquid phase fluid. The manifolds contain multichannel tubes of various end geometries designed to dispose flow channels at different heights within the manifold. Individual tubes also may be disposed at different heights within the manifold. The various flow channel and tube heights permit direction of vapor phase and liquid phase refrigerant to certain flow channels.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, heat exchangers, and multichannel tubes are provided which include internal configurations designed to promote mixing. The multichannel tubes include interior walls which form flow channels. The interior walls are interrupted at locations along the multichannel tube in order to provide open spaces between the flow channels where mixing may occur. The mixing that occurs promotes a more homogenous distribution of refrigerant within the multichannel tubes.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided that include multichannel tube and fin configurations designed to promote the release of condensate. The multichannel tubes may have a curved, round, or airfoil shape, and may be used with plate or corrugated fins. In certain embodiments, corrugated fins may be brazed to multichannel tubes and then trimmed to form individual fin structures. Double header configurations also may be employed.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and multi-slab heat exchangers are provided that include fluid connections for transmitting fluid between groups of tubes. The fluid connections may include generally tubular members fluidly connected to manifold sections. The fluid connections also may include partitioned manifolds containing tubes of different heights. Multichannel tubes are also provided that include a bent section configured to locate a flow path near a leading edge of a tube within one section and near a trailing edge of the tube within another section.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, heat exchangers, and multichannel tubes are provided which include internal configurations designed to promote mixing. The multichannel tubes include interior walls which form flow channels. The interior walls are interrupted at locations along the multichannel tube in order to provide open spaces between the flow channels where mixing may occur. The mixing that occurs promotes a more homogenous distribution of refrigerant within the multichannel tubes.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include tube and manifold configurations designed to promote separation of vapor phase and liquid phase fluid. The manifolds contain multichannel tubes of various end geometries designed to dispose flow channels at different heights within the manifold. Individual tubes also may be disposed at different heights within the manifold. The various flow channel and tube heights permit direction of vapor phase and liquid phase refrigerant to certain flow channels.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include manifold configurations designed to promote mixing of vapor phase and liquid phase refrigerant. The manifolds contain flow mixers such as a helical tape, sectioned volumes, and partitions containing apertures. The flow mixers direct the flow of refrigerant within the manifold to promote a more homogenous distribution of fluid within the multichannel tubes.

Abstract: Heat exchangers containing various tube configurations and a heating, ventilation, air conditioning and refrigeration (HVAC&R) system employing these heat exchangers are provided which allow flexibility in directing fluids through a heat exchanger. Groups of tubes may be placed at different locations within a heat exchanger slab in order to tailor the heat transfer properties of each tube group to their location on the heat exchanger slab. Groups of tubes may be connected using manifolds to create coil circuits.

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 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 centrifugal air blower has a housing with an inlet side wall through which a circular air inlet is formed. A cylindrical electric drive motor coaxially extends through the inlet opening and is drivingly coupled to a centrifugal impeller rotatably disposed within the housing. The motor is supported on the inlet side wall by a mounting system including a plurality of metal mounting rods each having an inner end, an outer end, and an elongated intermediate portion. The inner rod ends are welded to circumferentially spaced locations of a belly band structure coaxially clamped to the drive motor, and the outer rod ends are connected to resilient support assemblies arranged in a circumferentially spaced array on the outer side of the housing inlet side wall around the blower inlet opening.