Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and includes a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure includes a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: Systems and methods are provided for gas furnace systems, including a pressure transducer and optionally one or more pressure switches for efficiently achieving multiple operating modes and/or multiple fuel-to-air mixtures. The pressure transducer may determine a pressure setting at the heat exchanger and based on the pressure value may determine an amount to open a gas valve. As pressure transducer is capable of detecting a range of pressures, multiple different operational modes may be achieved by adjusting the opening of the gas valve depending on the detected pressure. The pressure switches may be used to calibrate and/or confirm the accuracy of the pressure transducer. For example, the output of a pressure switch may be compared to an output of a pressure transducer at a given inductor fan setting to determine whether the pressure transducer is accurate and/or calibrated.

Abstract: The present disclosure provides a climate control system including a first heat exchanger having a plurality of first channels to allow flow of water therethrough, a burner to heat the water in the first channels of the first heat exchanger, and an inducer disposed proximal to the burner to direct combustion air towards the burner for combustion, and vent products of combustion. The system further includes a hydronic coil-to-air heat exchanger in fluid communication with the first heat exchanger, to receive the heated water from the first heat exchanger. The hydronic coil-to-air heat exchanger includes a plurality of second channels to allow flow of heated water therethrough. The system also includes a blower to blow air across the plurality of second channels of the hydronic coil-to-air heat exchanger, whereby the air is heated by the heated water.

Abstract: The disclosed technology includes systems and methods for detecting an obstructed air filter in a furnace. The disclosed technology can include a method and system that includes an air inlet, an air filter for filtering particles from air passing through the air inlet, an air moving device, a fuel valve, a burner, a pressure sensor, and a controller in communication with the pressure sensor and configured to output an alarm signal when the controller receives differential pressure data from the pressure sensor that indicates that the air filter is obstructed.

Abstract: The disclosed technology includes systems and methods for detecting an obstructed air filter in a furnace. The disclosed technology can include a method and system that includes an air inlet, an air filter for filtering particles from air passing through the air inlet, an air moving device, a fuel valve, a burner, a pressure sensor, and a controller in communication with the pressure sensor and configured to output an alarm signal when the controller receives differential pressure data from the pressure sensor that indicates that the air filter is obstructed.

Abstract: A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

Abstract: Systems and methods for counter-flow heat reduction cycles are disclosed. Embodiments may include a gas furnace having a combustion air pipe, an exhaust air pipe, and a heat exchanger coupled to the combustion air pipe and the exhaust air pipe, the heat exchanger having a heat exchanger tube and an induced draft blower configured to direct air toward the heat exchanger tube, where the air flows over the heat exchanger tube and into the exhaust air pipe. The gas furnace may include a controller configured to determine a call for heat, activate the induced draft blower during a normal heating operation, determine that the call for heat is no longer present, determine that at least 70 seconds have elapsed since determining that the call for heat is no longer present, and deactivate the induced draft blower.

Abstract: Pre-mix fuel fired appliances having improved heat exchange interfaces are disclosed. Embodiments may include a fuel-fired heating appliance having a burner, a first housing comprising an outlet, the first housing disposed adjacent the burner and configured to receive combustion gas from combustion at the burner, and a heat exchanger having a heat exchanger tube with a first bend and a second bend, and an inlet disposed adjacent the outlet of the first housing. The heat exchanger may be configured to receive combustion gas from the first housing. The appliance may include a blower configured to direct air toward the first bend of the heat exchanger tube, and a heat transfer insert disposed at least partially in the heat exchanger tube, the heat transfer insert having a first end disposed in the first housing, and a second end disposed adjacent to the first bend of the heat exchanger tube.

Abstract: The disclosed technology includes systems and methods for detecting an at least partially obstructed air filter in a furnace. The disclosed technology can include a system and method that can receive temperature data from a flame sensor configured to detect a temperature of a flame in a burner, determine that an air filter associated with the burner is at least partially obstructed by determining that the temperature data indicates the flame temperature is greater than or equal to a threshold temperature, and output an alarm signal indicating that the air filter is at least partially obstructed.

Abstract: The present disclosure provides a climate control system including a first heat exchanger having a plurality of first channels to allow flow of water therethrough, a burner to heat the water in the first channels of the first heat exchanger, and an inducer disposed proximal to the burner to direct combustion air towards the burner for combustion, and vent products of combustion. The system further includes a hydronic coil-to-air heat exchanger in fluid communication with the first heat exchanger, to receive the heated water from the first heat exchanger. The hydronic coil-to-air heat exchanger includes a plurality of second channels to allow flow of heated water therethrough. The system also includes a blower to blow air across the plurality of second channels of the hydronic coil-to-air heat exchanger, whereby the air is heated by the heated water.

Abstract: A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and includes a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure includes a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and comprises a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure comprises a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: The disclosed technology includes systems and methods for detecting an at least partially obstructed air filter in a furnace. The disclosed technology can include a system and method that can receive temperature data from a flame sensor configured to detect a temperature of a flame in a burner, determine that an air filter associated with the burner is at least partially obstructed by determining that the temperature data indicates the flame temperature is greater than or equal to a threshold temperature, and output an alarm signal indicating that the air filter is at least partially obstructed.

Abstract: The disclosed technology includes systems and methods for detecting an obstructed air filter in a furnace. The disclosed technology can include a method and system that includes an air inlet, an air filter for filtering particles from air passing through the air inlet, an air moving device, a fuel valve, a burner, a pressure sensor, and a controller in communication with the pressure sensor and configured to output an alarm signal when the controller receives differential pressure data from the pressure sensor that indicates that the air filter is obstructed.

Abstract: A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and comprises a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure comprises a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: A fuel-fired furnace incorporates specially designed fuel/air mixing and combustion structures. The fuel/air mixing structure is of a mixing sound-attenuating design and comprises a venturi having a perforated sidewall portion and being surrounded by a noise-damping housing chamber communicating with the interior of the venturi via its sidewall perforations. During use of the mixing structure, air is flowed through the venturi in a swirling pattern while fuel is transversely injected internally against the swirling air. The combustion structure comprises a burner box housing into which the fuel/air mixture is flowed, combusted, and then discharged as hot combustion gas into and through the heat exchanger tubes. The fuel/air mixture entering the burner box housing initially passes through a non-uniformly perforated diffuser plate functioning to substantially alter in a predetermined manner the relative combustion gas flow rates through the heat exchanger tubes.

Abstract: A flame indicator assembly for a fuel-fired heating appliance, the fuel-fired heating appliance including a burner assembly and control electronics. The flame indicator assembly comprises a flame sensor configured to allow the flow of electric current in response to exposure to a flame. The flame sensor is configured for electrical communication with the control electronics of the fuel-fired heating appliance. The flame indicator assembly also comprises a visual indicator module attached to the flame sensor. The visual indicator module comprises at least one light source. The visual indicator module is in operative communication with the flame sensor such that the at least one light source is actuated in response to the flow of electric current. A fuel-fired heating appliance comprising a flame indicator assembly is also disclosed.