Abstract: Disclosed is a shell-and-tube heat exchanger assembly, having: a first tubesheet configured for being secured to a shell of the shell-and-tube heat exchanger assembly, the first tubesheet including: a first section and a second section; the second section configured to be secured to a first shell end of the shell; and the first section including a plurality of holes configured to support a respective plurality of aluminum tubes extending through the shell, wherein the first section is configured to limit a galvanic response of the plurality of aluminum tubes when exposed to a chiller water.

Abstract: Disclosed is a shell-and-tube heat exchanger assembly, having: a first tubesheet configured for being secured to a shell of the shell-and-tube heat exchanger assembly, the first tubesheet including: a first section and a second section; the second section configured to be secured to a first shell end of the shell; and the first section including a plurality of holes configured to support a respective plurality of aluminum tubes extending through the shell, wherein the first section is configured to limit a galvanic response of the plurality of aluminum tubes when exposed to a chiller water.

Abstract: A secondary heat exchanger for use in a condensing gas-fired HVAC appliance including at least one conduit, including a non-circular transverse cross-sectional geometry. In one instance, the at least one conduit penetrates and is in contact with at least one plate fin. In another instance a fin is affixed to the at least one conduit.

Abstract: An air treatment module includes an air plenum, a heat exchanger tube and a bypass duct. The bypass duct has an inlet opening in flow communication with the air plenum in juxtaposition with a selected region of the heat exchanger and an outlet opening in flow communication with a zone of lower air pressure. The presence of the bypass duct improves air flow over the heat exchanger tube in the selected region.

Abstract: A heat exchanger is provided including a plurality of heat exchanger tubes. A first fluid flows through each heat exchanger tube and a second fluid flows around an exterior of each heat exchanger tube. A turbulator is disposed within at least one of the heat exchanger tubes. The turbulator extends at least a portion of the length of the heat exchanger tube. The turbulator includes a generally flat sheet of material having a plurality of integrally formed turbulence generating elements. The turbulence generating elements extend from a plane of the sheet of material into the first fluid flow. A disturbance is created in the first fluid flow adjacent each turbulence generating element.

Abstract: A heating apparatus for a heat exchanger system includes a manifold having a plurality of burners, a shutoff valve, a first controller and a second controller. The shutoff valve divides the manifold into a first manifold portion and a second manifold portion. The first controller selectively controls the communication of a fluid within the manifold. The second controller selectively actuates the shutoff valve between a first position and a second position to control a firing rate of the plurality of burners.

Abstract: An air treatment module includes an air plenum, a heat exchanger tube and a bypass duct. The bypass duct has an inlet opening in flow communication with the air plenum in juxtaposition with a selected region of the heat exchanger and an outlet opening in flow communication with a zone of lower air pressure. The presence of the bypass duct improves air flow over the heat exchanger tube in the selected region.

Abstract: A heat exchanger tube for a gas furnace is provided. The heat exchanger tube may include an inlet, an outlet and one or more asymmetric dimple pairs disposed between the inlet and the outlet. The inlet and the outlet may form a passageway through the heat exchanger tube for receiving a heated combustion gas. Each asymmetric dimple pair may provide a first dimple and an opposing second dimple. The first and second dimples may be configured to at least partially constrict flow of the gas therethrough. Together, the first and second dimples may form an upstream section, a downstream section and a merge point.

Abstract: A heating apparatus for a heat exchanger system includes a manifold having a plurality of burners, a shutoff valve, a first controller and a second controller. The shutoff valve divides the manifold into a first manifold portion and a second manifold portion. The first controller selectively controls the communication of a fluid within the manifold. The second controller selectively actuates the shutoff valve between a first position and a second position to control a firing rate of the plurality of burners.

Abstract: Air is heated by a gas or electric heat exchanger or cooled in an evaporator coil. The air is discharged through a discharge opening to heat or cool an area. Two fans draw an exterior air stream over the gas or electric heat exchanger or the evaporator coil. A first fan has a diameter greater than a diameter of a second fan. When in a side discharge configuration, the second fan is located between the first fan and the side discharge opening. The first fan has a larger diameter to produce a stronger airflow to overcome the airflow produced by the second fan, better distributing the airflow from the first fan. The airflow generated by the second fan is directed to the discharge opening relatively unimpeded.

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 apparatus for reducing the resonant type noise generated in a combustion driven heating apparatus. A dissipative device is disposed within a hot gas passageway to absorb and attenuate acoustic wave energy and thereby reducing the resonant noise level of the heating apparatus.