Abstract: A coupling to connect a primary heat exchanger to a condensing heat exchanger of a furnace includes a coupling box extending between a primary heat exchanger and a condensing heat exchanger. The coupling box defines a flow path for flue gas between a primary heat exchanger outlet and a condensing heat exchanger inlet. A tube sheet is located at a distance from the tube sheet in the coupling box. The liner and the tube sheet define an insulating liner space therebetween reducing condensation on the liner.

Abstract: A latch assembly for securing a furnace door to a furnace casing includes a latch for placement on an inside of the furnace door; a knob for placement on a front surface of the furnace door; a latch plate for placement between the latch and the knob; and a threaded screw for threadably coupling the knob to the latch. The latch plate supports the weight of the furnace door in a closed position and reduces a pinch force used for rotating the knob.

Abstract: A compact furnace heat exchanger for a gas furnace is disclosed. The compact furnace heat exchanger may include a first pass having an inlet end, a second pass in fluid communication with the first pass through a first return bend, and a third pass having an outlet end and in fluid communication with the second pass through a second return bend. The third pass may further include a plurality of irregularities for optimizing performance of the compact furnace heat exchanger and the associated gas furnace.

Abstract: A latch assembly for securing a furnace door to a furnace casing, the latch assembly comprising: a latch for placement on an inside of the furnace door; a knob for placement through a hole in the furnace door, the knob snapped into the latch, the knob for placement on a front surface of the furnace door; a gasket for placement between the knob and the latch; and a cap secured at an end of the knob, wherein the latch, knob, and cap are keyed to allow assembly in only one orientation.

Abstract: A latch assembly for securing a furnace door to a furnace casing includes a latch for placement on an inside of the furnace door; a knob for placement on a front surface of the furnace door; a latch plate for placement between the latch and the knob; and a threaded screw for threadably coupling the knob to the latch. The latch plate supports the weight of the furnace door in a closed position and reduces a pinch force used for rotating the knob.

Abstract: An informational label for a component of a heating ventilation and air conditioning (HVAC) unit includes a sheet including a plurality of panels foldable from an opened configuration into a closed configuration. The sheet exhibits at least one of resistance to heat or resistance to moisture of an operating environment. A closure is utilized to secure the plurality of panels in the closed configuration, and a layer of adhesive is applied to a panel of the plurality of panels to secure the informational label to an HVAC component.

Abstract: A latch assembly for securing a furnace door to a furnace casing, the latch assembly comprising: a latch for placement on an inside of the furnace door; a knob for placement through a hole in the furnace door, the knob snapped into the latch, the knob for placement on a front surface of the furnace door; a gasket for placement between the knob and the latch; and a cap secured at an end of the knob, wherein the latch, knob, and cap are keyed to allow assembly in only one orientation.

Abstract: A coupling to connect a primary heat exchanger to a condensing heat exchanger of a furnace includes a coupling box extending between a primary heat exchanger and a condensing heat exchanger. The coupling box defines a flow path for flue gas between a primary heat exchanger outlet and a condensing heat exchanger inlet. A tube sheet is located at the condensing heat exchanger inlet and a liner is located at a distance from the tube sheet in the coupling box. The liner and the tube sheet define an insulating liner space therebetween reducing condensation on the liner.

Abstract: A furnace includes a cabinet having a top plate and a blower located in the cabinet. A blower shelf is located in the cabinet and has a first side supportive of the blower and a second side including one or more canted slide rails. A heat exchanger is located in the cabinet between the blower and the top plate and is securable to the one or more canted slide rails. The one or more canted slide rails are configured to allow removal of the heat exchanger from the cabinet along the canted slide rails without removal of the top plate from the cabinet.

Abstract: A compact furnace heat exchanger for a gas furnace is disclosed. The compact furnace heat exchanger may include a first pass having an inlet end, a second pass in fluid communication with the first pass through a first return bend, and a third pass having an outlet end and in fluid communication with the second pass through a second return bend. The third pass may further include a plurality of irregularities for optimizing performance of the compact furnace heat exchanger and the associated gas furnace.