Abstract: A mounting system for mounting a pressure switch to a mounting body without using screws or brackets. The mounting system includes a support physically supporting the pressure switch on the mounting body, a conduit carrying a pressure signal from the mounting body to the pressure switch, and a connector extending between and connecting the support to the conduit. The support and conduit may have ends constructed of synthetic rubber to frictionally engage support and conduit mounts, and the support and conduit may have approximately the same length and/or the same cross-sectional shape. The mounting body may be a draft inducer, a condensate collector box, or a drain trap in a furnace.

Abstract: A safety system for a heating apparatus includes an inlet for receiving input gases for combustion and a flue for expelling flue gases. A carbon monoxide sensor is also included for monitoring carbon monoxide content in the heating apparatus. The safety system also includes a pressure switch which permits the input gases to mix with the flue gases based on the information from the carbon monoxide sensor.

Abstract: A mounting system for mounting a pressure switch to a mounting body without using screws or brackets. The mounting system includes a support physically supporting the pressure switch on the mounting body, a conduit carrying a pressure signal from the mounting body to the pressure switch, and a connector extending between and connecting the support to the conduit. The support and conduit may have ends constructed of synthetic rubber to frictionally engage support and conduit mounts, and the support and conduit may have approximately the same length and/or the same cross-sectional shape. The mounting body may be a draft inducer, a condensate collector box, or a drain trap in a furnace.

Abstract: A gas burner for low NOx gas furnaces is disclosed with improved flame carryover for igniting one or more adjacent burners. The burner includes a burner tube that receives a mixture of fuel and air. The burner tube is coupled to an outlet. The outlet includes a primary outlet opening which is in communication with at least one transverse slot for communicating a flame to at least one adjacent burner. The primary outlet opening may be elliptical and the outlet further may also include a concave outer face through which the primary outlet opening extends. The at least one slot may include a pair of oppositely directed transverse slots extending outward from the primary outlet opening along a semi-minor axis of the primary outlet opening.

Abstract: A burner assembly includes a burner housing having a fuel inlet; a burner for emitting ignited fuel to a heat exchanger; and an igniter and flame sensor assembly mounted to the burner housing, the igniter and flame sensor assembly including an opening therein providing an air path from an exterior of the burner housing to an interior of the burner housing, the opening sized to provide a predetermined drop of carbon dioxide at an outlet of the heat exchanger.

Abstract: An improved induced draft gas burner assembly for low NOx residential and light commercial gas furnaces is disclosed. The improved burner includes an upstream assembly coupled to a fuel inlet and an air inlet. The air inlet is coupled to a neck extending between the air inlet and the outlet of the neck, both of which may be disposed within an optional chamber. If used, such a chamber also includes an outlet coupled to a burner. In practice, the chamber and neck behave as a Helmholtz resonator that can be tuned to provide an upstream impedance Zup that exceeds the downstream impedance Zdown of the components downstream of the burner assembly.

Abstract: A burner assembly includes a burner housing having a fuel inlet; a burner for emitting ignited fuel to a heat exchanger; and an igniter and flame sensor assembly mounted to the burner housing, the igniter and flame sensor assembly including an opening therein providing an air path from an exterior of the burner housing to an interior of the burner housing, the opening sized to provide a predetermined drop of carbon dioxide at an outlet of the heat exchanger.

Abstract: A gas burner for low NOx gas furnaces is disclosed with improved flame carryover for igniting one or more adjacent burners. The burner includes a burner tube that receives a mixture of fuel and air. The burner tube is coupled to an outlet. The outlet includes a primary outlet opening which is in communication with at least one transverse slot for communicating a flame to at least one adjacent burner. The primary outlet opening may be elliptical and the outlet further may also include a concave outer face through which the primary outlet opening extends. The at least one slot may include a pair of oppositely directed transverse slots extending outward from the primary outlet opening along a semi-minor axis of the primary outlet opening.

Abstract: A furnace with a push and pull combustion system is disclosed. The furnace may include a cabinet housing a burner box, a gas valve assembly, a premix chamber, a heat exchanger, a blower, an induced-draft blower, and a flue pipe. The gas valve assembly may meter gas into the premix chamber, while the blower may draw air into the premix chamber, wherein air and gas may mix to produce a lean gas/air mixture. The blower may also push the lean gas/air mixture into the burner box. The burner box may ignite the lean gas/air mixture to produce combustion products. A blocked vent safety shutoff switch may be mounted over an opening of the burner box to ensure negative pressure by detecting any leakage of combustion products. The induced-draft blower may pull the combustion products through the heat exchanger, the flue pipe, and out into the atmosphere.

Abstract: An ignition system for a gas furnace being controlled by a main controller and having at least one burner is provided. The ignition system may include at least one flame sensor and an interface module. The flame sensor may be disposed in close proximity to the burner and configured to output a flame check signal indicative of a status of a flame at the burner. The interface module may be configured to receive the flame check signal and generate a fault check signal based on the flame check signal.

Abstract: An improved induced draft gas burner assembly (31, 131, 231, 331, 431, 531, 631) for low NOx residential and light commercial gas furnaces (10, 10a) is disclosed. The improved burner includes an upstream assembly coupled to a fuel inlet (55) and an air inlet (43). The air inlet (43) is coupled to a neck (41, 141, 241, 341, 441, 541, 641) extending between the air inlet (43) and the outlet of the neck (41, 141, 241, 341, 441, 541, 641), both of which may be disposed within an optional chamber (42, 142, 242, 342, 442). If used, such a chamber (42, 142, 242, 342, 442) also includes an outlet coupled to a burner (46, 146, 246, 346, 546, 646). In practice, the chamber (42, 142, 242, 342, 442) and neck (41, 141, 241, 341, 441, 541, 641) behave as a Helmholtz resonator that can be tuned to provide an upstream impedance Zup that exceeds the downstream impedance Zdown of the components downstream of the burner assembly (31, 131, 231, 331, 431, 531, 631).

Abstract: An improved furnace including a two-speed inducer motor which can be used as a single speed motor for either a vertically or horizontally vented furnaces. The inducer has a common terminal, a low speed terminal and a high speed terminal. One lead is attached to the common terminal and, depending on whether the furnace is vented horizontally or vertically, either the high speed or low speed terminal is used. If the furnace is vented vertically, one lead is connected to the common terminal and the other lead is connected to the low speed terminal. Thus the furnace operates at a low speed when the furnace is vented vertically. If the furnace is vented horizontally, one lead is connected to the common terminal and the other lead is connected to the high speed terminal. Thus, the inducer motor operates at the higher speed when the furnace is vented horizontally.

Abstract: An improved furnace is provided which can be field modified to change the pressure drop across the inducer. The pressure drop is modified to accommodate vertical or horizontal venting and adequately lined and inadequately lined chimneys. A first rate of flow of combustion byproducts into the vent system is used when the chimney is adequately lined and a second relatively higher rate of flow is used when the chimney is inadequately lined. The rate of flow is changed by inserting or removing an obstruction in the flow of combustion byproducts. The obstruction could be a tab or choke placed at the inducer outlet or a similar device in the inducer inlet. When the tab is in place the flow of combustion byproducts is reduced. When the tab is removed, the flow rate increases. Alternatively, the inducer inlet could be adjusted to increase or decrease the amount of air flow through the inducer.

Abstract: An apparatus senses the pressure changes in a collector box or relief box of a furnace due to changing wind conditions, and adjusts the gas flow accordingly. The apparatus controls the main gas valve of the furnace through a regulator loop. The regulator loop has a first port that communicates with a chamber below the main diaphragm of the valve, and a second port that communicates with a chamber above the main diaphragm. The regulator includes two diaphragms linked rigidly. A feedback pressure channel is connected to the collector box or the relief box, at one end, and to a feedback pressure tap at the other end. An increase in wind at the furnace vent causes changes in pressure in the collector box and the relief box. This change in pressure is delivered to the feedback pressure tap. When the pressure at the feedback pressure tap increases, the top diaphragm and the bottom diaphragm both move upward.

Abstract: A furnace control apparatus is described wherein a flow of gas into a burner assembly is directly dependent on an indicia of burner combustion air airflow, such as heat exchanger pressure drop. According to one embodiment of the invention, a first communication fluid line is interposed between a gas valve regulator and a heat exchanger at a first point, and a second communication fluid line is interposed between a gas valve regulator a heat exchanger at a second point. The main valve of the gas valve is responsive to the pressure differential between the first and second points so that a flow of gas into a furnace burner assembly is commensurate with a present flow level of combustion air.

Abstract: A heating apparatus for delivering heated air to an enclosure comprising a casing with at least two compartments separated by a panel. A burner with an arcuate profile is located within a first compartment of the casing for burning a combustible fuel-air mixture delivered thereto and producing products of combustion. A heat exchanger is located within a second compartment of the casing and has an opposed inlet and outlet. The inlet is in fluid communication with the burner through an aperture in the panel. The heat exchanger receives the products of combustion. A blower is located within the casing for directing a flow of air across the heat exchanger into the enclosure. Through the heat exchanger heat is transferred from the products of combustion to the air. An exhaust system is in fluid communication with the outlet and includes a vent for exhausting the products of combustion from the casing. The vent is contained within the casing.

Abstract: A mixing/quenching device is in the form of a stack of perforate metal sheets secured together with the perforations aligned to define continuous flow paths. The interfaces of the laminations in the flow path provides turbulence and the thermal mass of the device provides heat transfer such that thermal NO.sub.x is reduced.

Abstract: An electric plug locking device (10), which remains affixed to an electric plug (13) for preventing unsupervised use of electrical equipment, has an upper housing member (11) movably mounted to a lower housing member (12). The upper housing member which has an opening (23) for receiving a plug terminal (15) moves from a position that shields the terminal to prevent it from being inserted into an electrical socket to a position that unshields the plug terminal to permit it to be inserted into the socket.