A furnace for a heating, ventilation, and air conditioning (HVAC) system, comprises a burner configured to ignite a mixture of air and fuel and a sensor configured to detect a parameter indicative of an intensity of sound generated by the furnace and configured to transmit a signal indicative of a value of the parameter. The furnace further comprises a controller configured to receive the signal indicative of the value of the parameter, compare the value of the parameter to a threshold value, and in response to a determination that the value of the parameter meets or exceeds the threshold value, control operation of the furnace to adjust a flow rate of the air, a flow rate of the fuel, or both.

One aspect of this disclosure provides a heating chamber for a gas furnace that comprises opposing halves joined together. The joined opposing halves form a clamshell panel having at least one truncated corner located adjacent a curve located at a back end of a chamber path of the one or more clamshell heating chambers.

One aspect of this disclosure provides a heating chamber for a gas furnace that comprises opposing halves joined together. The joined opposing halves form a clamshell panel having at least one truncated corner located adjacent a curve located at a back end of a chamber path of the one or more clamshell heating chambers.

A system for mounting a heater to structural members having a predetermined spacing includes a first mounting bracket having first and second mounting locations. The first and second mounting locations are spaced apart by a first integer multiple of the predetermined spacing. The system also includes a second mounting bracket having third and fourth mounting locations. The third and fourth mounting locations re spaced apart by the first integer multiple of the predetermined spacing. The system further includes a plurality of attachment points on the heater for attaching the first and second mounting brackets to the heater. The plurality of attachment points is arranged to locate the first, second, third, and fourth mounting locations in a mounting plane, with both the first and the third mounting locations and the second and the fourth mounting locations being spaced apart by a second integer multiple of the predetermined spacing.

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.

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.

A setting value change device is provided whereby change operations to correct temperature setting values or hot water amount values by drag operations are easy. A controller causes a display to display a drag button and a movement path on which the drag button moves. Additionally, the controller provides, on a touch sensor, a drag area for detecting a drag input on the drag button and a reference point disposed at a location off the movement path. Moreover, the controller is configured to set the drag area larger than the display range of the movement path, move the drag button to a crossing point where a straight line or specific curve connecting the reference point to a drag operation position in the drag area crosses the movement path, and change the temperature setting value to the value corresponding to the position of the drag button.

A combustion heater generates heat by means of flame. The combustion heater is disposed adjacent to a refrigerant circuit filled with a combustible refrigerant. The combustion heater includes a combustion unit and a porous body. The combustion unit causes generation of flame. The porous body covers the combustion unit or a periphery of the combustion unit. The porous body at least partially covers both or one of a combustion space receiving combustible refrigerant leaking from the refrigerant circuit and a member in contact with the combustible refrigerant leaking from the refrigerant circuit. The porous body has a plurality of holes. The holes have a diameter d1 equal to or less than an extinction diameter d of the combustible refrigerant.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.