Abstract: An alternative-fuel gas orifice, a gas furnace configured to employ the same and a method of designing a gas orifice. In one embodiment, the gas orifice includes: (1) a body having an aperture extending therethrough and including: (1a) a metering neck having a cross-sectional area such that a given flow rate of a gas is established when the gas is delivered to the gas orifice at a given alternative-fuel delivery pressure and (1b) a diffuser having a cross-sectional area larger than the cross-sectional area of the metering neck and a length such that the gas achieves a substantially laminar flow before exiting the diffuser.

Abstract: A controller for a gas furnace, a computer-usable medium for implementing a method and a gas furnace are disclosed herein. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a processor configured to enable an inducer of the gas furnace at a low speed based on the heating call and ignite the gas furnace at a high fire operation when determining a low fire pressure switch of the gas furnace is open.

Abstract: A gas-air mixer assembly is described that helps mix fuel and air within an HVAC system. The mixer assembly can also achieve lower pressure drops than seen in other solutions. A mixer assembly can comprise a mixer body through which air is supplied. An orifice body can extend into the stream of air within the mixer body and then point upstream. A tip of the orifice body, disposed in the airstream, can provide fuel through one or more orifices. The flow of air around the orifice body helps to cause mixing, as does an elbow bend in the mixer body, downstream of the orifice body.

Abstract: A burner assembly according to aspects of the disclosure includes a burner surface carried by a burner, the burner surface extending outward from a front side of the burner, a housing coupled to the burner on a side opposite the front side of the burner, a gasket disposed between the burner and the housing, a thermally anisotropic protective covering located on the front side of the burner and surrounding a perimeter of the burner surface, and an igniter positioned adjacent to the burner surface.

Abstract: A method of monitoring a HVAC system to detect erroneous sensor installation. The method includes determining whether a circulation fan has been operational for a first predetermined time interval. If the circulation fan has been operational for the first predetermined time interval, determining whether a cooling demand is present. If the cooling demand is present, determining whether the HVAC system has been conditioning air for the first predetermined time interval responsive to the cooling demand. If the HVAC system has been conditioning the air for the first predetermined time interval, determining whether a difference between an indoor air temperature value corresponding to an enclosed space and an air temperature value from a discharge air temperature (DAT) sensor is greater than a predetermined temperature value.

Abstract: Systems and methods are described related to a premix combustion system used in a furnace system. Prior systems have to create a negative pressure in the premix chamber to draw gas into the chamber. Embodiments under the current disclosure can use an amplifier that is pneumatically coupled to an air supply and a secondary location (besides the gas valve). Coupling to the amplifier to a location apart from the gas valve allows the system to avoid a negative pressure in the mixing chamber. The amplifier can apply an amplified pressure or signal to a gas valve regulator and thereby raise the gas pressure so that the gas supply is driven into the premix chamber.

Abstract: Systems and methods are described for a screen assembly for gas-air mixers in HVAC systems, such as for furnaces. A screen assembly can comprise a mesh screen, a housing, and a pressure tap. The mesh screen can allow for the intake of an air supply while also blocking unwanted foreign matter such as dust or leaves. The housing can receive the air supply and direct it into a gas-air mixer or other component. The pressure tap can be coupled to a gas valve or regulator in order to modulate the flow of gas when air flow is restricted.

Abstract: The disclosure provides a controller for a multistage gas furnace, a multistage gas furnace and computer readable medium for performing a method to operate a furnace. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a corrosion reducer configured to ignite the gas furnace at a high fire operation based on if an indoor circulating fan of the gas furnace is active.

Abstract: A condensation trap comprising an inlet chamber, a vent chamber and an outlet chamber. The inlet chamber is configured to receive condensate fluid through an external opening therein. The vent chamber is in fluid communication with the inlet chamber via a first passageway that includes an internal opening of the inlet chamber. The internal opening is located substantially at an opposite end of the vent chamber as the external opening. The outlet chamber is in fluid communication with the vent chamber via a second passageway that includes an internal opening in a sidewall of the vent chamber and an interior opening in an end of the outlet chamber. The outlet chamber is configured to transmit the condensate fluid through an exterior opening located at an opposite end of the outlet chamber. A vent volume portion is greater than a total volume of an internal space of the inlet chamber.

Abstract: A gas-air mixer assembly is described that helps mix fuel and air within an HVAC system. The mixer assembly can also achieve lower pressure drops than seen in other solutions. A mixer assembly can comprise a mixer body through which air is supplied. An orifice body can extend into the stream of air within the mixer body and then point upstream. A tip of the orifice body, disposed in the airstream, can provide fuel through one or more orifices. The flow of air around the orifice body helps to cause mixing, as does an elbow bend in the mixer body, downstream of the orifice body.

Abstract: A condensation management system, a furnace having the condensation management system and a cold end header box employable in the condensation management system are disclosed herein. In one embodiment, the condensation management system includes: (1) a first drain hose positioned to drain flue condensation from a flue pipe of the furnace, (2) a second drain hose positioned to drain the flue condensation from the flue pipe and (3) a condensation collector box configured to collect both the flue condensation and combustion condensation from a heat exchanger of the furnace, the condensation collector box including at least one drain for draining both the flue condensation and the combustion condensation therefrom.

Abstract: A controller for a gas furnace, a computer-usable medium for implementing a method and a gas furnace are disclosed herein. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a processor configured to enable an inducer of the gas furnace at a low speed based on the heating call and ignite the gas furnace at a high fire operation when determining a low fire pressure switch of the gas furnace is open.

Abstract: A header box, a furnace and a blocked condensation protection system are disclosed herein. In one embodiment, the header box includes: (1) a first channel having a first channel supply port positioned to be in fluid communication with an inlet of a combustion air blower and a first pressure port couplable to a first input of a pressure sensing device, the combustion air blower and the pressure sensing device associated with the cold end header box and (2) a second channel having a second channel supply port positioned to be in fluid communication with the inlet of the combustion air blower, a second pressure port couplable to a second input of the pressure sensing device and a pressure reference inlet, the second channel in fluid communication with the first channel and configured to have about a same pressure as the first channel when the pressure reference inlet is blocked.

Abstract: A controller for a gas furnace, a computer-usable medium for implementing a method and a gas furnace are disclosed herein. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a processor configured to enable an inducer of the gas furnace at a low speed based on the heating call and ignite the gas furnace at a high fire operation when determining a low fire pressure switch of the gas furnace is open.

Abstract: A condensation trap comprising an inlet chamber, a vent chamber and an outlet chamber. The inlet chamber is configured to receive condensate fluid through an external opening therein. The vent chamber is in fluid communication with the inlet chamber via a first passageway that includes an internal opening of the inlet chamber. The internal opening is located substantially at an opposite end of the vent chamber as the external opening. The outlet chamber is in fluid communication with the vent chamber via a second passageway that includes an internal opening in a sidewall of the vent chamber and an interior opening in an end of the outlet chamber. The outlet chamber is configured to transmit the condensate fluid through an exterior opening located at an opposite end of the outlet chamber. A vent volume portion is greater than a total volume of an internal space of the inlet chamber.

Abstract: A flue shield and mesh baffle are described for use within HVAC systems and inside of a combustion chamber. The shield or baffle can be installed around the burner and within the combustion chamber to help dissipate heat that builds up as a result of the combustion of gas and air. An air gap is created between the flue shield and the inner surfaces of the combustion chamber and heat exchanger tubes. A mesh baffle can provide heat insulation and noise dampening. Installation of a flue shield or mesh baffle provides better efficiency than insulation solutions, reduces stresses on the heat exchanger, and provides safety benefits.

Abstract: A flue shield is described for use within HVAC systems and inside of a combustion chamber. The flue shield can be installed around the burner and within the combustion chamber to help dissipate heat that builds up as a result of the combustion of gas and air. Extensions from the flue shield extend through holes in the combustion chamber and into tubes of a heat exchanger. An air gap is created between the flue shield and the inner surfaces of the combustion chamber and heat exchanger tubes. Installation of a flue shield provides better efficiency than insulation solutions, reduces stresses on the heat exchanger, and provides safety benefits.

Abstract: Provided herein are embodiments of, a multistage gas furnace, a controller therefor and a computer-usable medium having non-transitory computer readable instructions stored thereon for execution by a processor to perform a method for operating a gas furnace. In one embodiment, the gas furnace includes: (1) a burner, (2) a circulation fan and (3) a furnace controller. The furnace controller having: (3A) an interface configured to receive heating calls and a blower control signal, the blower control signal corresponding to an operating speed of the circulation fan and (3B) a processor configured to respond to the heating calls and the blower control signal by setting and adjusting a gas input rate for the burner that is based on the blower control signal and that corresponds to a discharge air temperature determined by a dedicated discharge air sensor associated with the furnace.

Abstract: The disclosure provides a controller for a multistage gas furnace, a multistage gas furnace and computer readable medium for performing a method to operate a furnace. In one embodiment, the controller includes: (1) an interface configured to receive a heating call and (2) a corrosion reducer configured to ignite the gas furnace at a high fire operation based on if an indoor circulating fan of the gas furnace is active.