Abstract: Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

Abstract: Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

Abstract: Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

Abstract: A furnace may include a furnace cabinet, an inducer blower, and a flue vent adapter. The furnace is configured as a multi-poise furnace and configured to be installed and operated in each of the horizontal left flow orientation, the horizontal right flow orientation, the upflow orientation, and the downflow orientation. The flue vent adapter is used when the furnace is installed and operated in the downflow orientation. Alternatively, the flue vent adapter is used when the furnace is installed and operated in each of the horizontal left flow orientation and the horizontal right flow orientation. The flue vent adapter has a unitary construction to reduce manufacturing costs, reduce a pressure drop through the flue vent adapter, and reduce leakage.

Abstract: A heat exchanger tube includes a first pass for at least partially combusting a fuel and the first pass having a modified shape including a minor diameter and major diameter that reduces the external pressure drop of an external fluid flowing across the heat exchanger tube. A HVACR system includes a heat exchanger tube with a first heat exchange pass that at least partially combusts a fuel and has a modified shape. A method of making a heat exchanger including configuring a first heat exchange pass such that the major diameter of modified portion of the first heat exchange pass is oriented towards an incoming direction of the process fluid.

Abstract: A furnace may include a furnace cabinet, an inducer blower, and a flue vent adapter. The furnace is configured as a multi-poise furnace and configured to be installed and operated in each of the horizontal left flow orientation, the horizontal right flow orientation, the upflow orientation, and the downflow orientation. The flue vent adapter is used when the furnace is installed and operated in the downflow orientation. Alternatively, the flue vent adapter is used when the furnace is installed and operated in each of the horizontal left flow orientation and the horizontal right flow orientation. The flue vent adapter has a unitary construction to reduce manufacturing costs, reduce a pressure drop through the flue vent adapter, and reduce leakage.

Abstract: A heat exchanger tube includes a first pass for at least partially combusting a fuel and the first pass having a modified shape including a minor diameter and major diameter that reduces the external pressure drop of an external fluid flowing across the heat exchanger tube. A HVACR system includes a heat exchanger tube with a first heat exchange pass that at least partially combusts a fuel and has a modified shape.

Abstract: A heating, ventilation, and/or air conditioning (HVAC) system may include a heat exchanger comprising at least one heat exchanger tube. The heat exchanger tube may include multiple passes: a first pass, a second pass having an elliptical portion with ribs disposed in the elliptical portion, a third pass having an elliptical portion with ribs disposed in the elliptical portion, and a fourth pass having an elliptical portion with ribs disposed in the elliptical portion. The first pass and the second pass may be connected in fluid communication by a first bend, the second pass and the third pass may be connected in fluid communication by a second bend, and the third pass and the fourth pass may be connected in fluid communication by a third bend. The heat exchanger tube may be configured to promote heat transfer while also controlling a pressure drop across the heat exchanger tube.