Lennox Industries Inc.

Other

Lennox Technologies Inc.

Joe R Powell

Randall Lee Lisbona

Darko Hadzidedic

Hermon Alan Boyd

Lee Nelson

Timothy E Wallaert

Mark W Olsen

Stephen A Walter

Vijay Sathyamurthi

Kenneth H Stamps

Clifford A Watson

Charles D Bishop

Virginia N MacDonald

Russell C Tharp

Ajith Kumar Cherumani

A method of operating a HVAC system is provided. The method includes transferring heat between airflow and a heating element in the duct system. The heating element is configured to receive a fuel and ignite the fuel to heat the heating element. The method includes measuring a change in at least one gas property value of the airflow in the duct system using a leak detection sensor, where the change in the at least one gas property value is indicative of a gas leaked into the duct system. The method includes determining a concentration of the leaked gas based at least in part upon the change in the at least one gas property value and determining that the concentration as measured by the leak detection sensor has a negative value, where the negative value is indicative of the leaked gas comprising fuel.

Leak sensors for a HVAC system to detect fuel leaks and methods of operation

Systems, tools, and methods are presented that enable a circuit to introduce a random time delay before actuating a relay to start or stop a supply of electrical power to a heating element of a heating, ventilating, and air conditioning (HVAC) system. In one instance, the circuit includes a time-delay switch electrically connected to the relay. The time-delay switch has a random time delay before entering a closed state or open state. The relay is operable to start and stop a supply of electrical power to the heating element in response to the switch entering, respectively, the closed state and the open state. Other systems, tools and methods are presented. Other systems, tools and methods are presented.

HVAC systems and methods with improved heating element control

Systems, tools, and methods are presented that enable a circuit to introduce a random time delay before actuating a relay to start or stop a supply of electrical power to a heating element of a heating, ventilating, and air conditioning (HVAC) system. In one instance, the circuit includes a time-delay switch electrically connected to the relay. The time-delay switch has a random time delay before entering a closed state or open state. The relay is operable to start and stop a supply of electrical power to the heating element in response to the switch entering, respectively, the closed state and the open state. Other systems, tools and methods are presented.

In various implementations, a condition of a motor may be monitored based at least partially on time required to achieve a change in speed. A notification may be transmitted based on the condition of the motor.

Monitoring motor condition

A surge protector, an HVAC unit including the surge protector and a method of testing electrical equipment employing the surge protector is disclosed. In one embodiment, the surge protector includes: (1) a first lead, a second lead and a third lead and (2) a protective network having three surge protection units with one of the three surge protection units coupled between each distinct combination of the first, second and third leads, the protective network configured to provide simultaneous surge protection between each of the distinct combinations.

Surge protector, an HVAC unit including the surge protector and a method of testing electrical equipment

The disclosure includes an HVAC data processing and communication network and a method of manufacturing the same. In one embodiment the network includes a duct, a blower and a controller. The blower is configured to receive a control message from a data bus. The duct is configured to direct air flow from the blower. The controller is configured to publish the control message to the data bus. The controller thereby commands the blower to provide air to the duct at an initial volume rate and to increase the volume rate until the controller detects onset of a cutback mode of the blower.

Alarm and diagnostics system and method for a distributed architecture heating, ventilation and air conditioning network

The present invention is an improvement to previously known systems for controller area networks and the method of communicating across such networks. The system and method introduces interpolated time markers to provide higher resolution bit container, for communicating data bits across the data bus of a three-wire controller area network. The interpolated time markers allow devices on a controller area network to effectively double tie amount of bandwidth available for communication and can in some cases even further increase the bandwidth beyond a factor of two.

System and method of transmitting data within a three-wire network

Activation and deactivation of a plurality of heating elements in an electric heating system are separately controllable in accordance with the present invention. Individual heating elements are sequentially activated in response to a demand for heat. A predetermined time delay is imposed between successive activations of the heating elements to allow time to satisfy the demand for heat before another heating element is activated. Normally, the heating elements are also deactivated sequentially in response to a reduced demand for heat, with a predetermined time delay between successive deactivations to allow time to respond to the reduced demand for heat before another heating element is deactivated. A temperature sensor is located in the air discharge plenum of the heating system for sensing the temperature of the discharge air. The discharge air temperature is used to control the operation of the heating elements, a two-speed heat pump, and the 'off cycle' of the heating system blower.

Electric heat control apparatus and method

An improved timed-off control apparatus and method are provided to prevent excessive cycling of an electrically operated device, such as an air conditioning compressor. The timed-off control apparatus provides a predetermined timed-off period (e.g., five minutes), during which the electrically operated device is constrained to remain in an off state after the device is deactivated by a loss of power. For example, in an air conditioning system, fluctuations in power supply voltage and thermostat switch bounces may result in excessive cycling of the system compressor. By constraining the compressor to remain deactivated for the selected timed-off period, the compressor is protected against excessive cycling. In order to achieve consistent and predictable timed-off periods, a field effect transistor (FET) is used in conjunction with a resistance/capacitance (RC) circuit. When the power supply is interrupted, the FET is turned off state and remains off during the timed-off period. When the FET is off, the compressor remains off, even if electrical power becomes available during the timed-off period. The FET monitors the voltage across the capacitor of the RC circuit while the capacitor is being discharged and when the voltage drops below a predetermined threshold, the FET is turned on to allow resumption of compressor operation. The time at which the voltage across the capacitor reaches the predetermined threshold is a function of the capacitor discharge rate. Because the FET does not draw biasing current, the capacitor discharge rate is not affected by the FET. Therefore, consistent and predictable timed-off periods are achieved.

Timed-off control apparatus and method

Automatic food frying and dispensing apparatus is disclosed which is housed in a supporting cabinet and includes a device for holding a supply of cooking oil and a heating device for maintaining the temperature of the cooking oil at a predetermined temperature. A fan assembly exhausts air through the top of the cabinet. A derated precipitator, a flame arrester and a charcoal filter are positioned upstream of the fan assembly and in the path of air flow. A switch device is positioned in the path of air flow and shuts off the heating device if the air flow drops below a predetermined value. Food handling apparatus automatically lowers the food to be cooked into the cooking oil when a customer selects a desired cooking time and automatically raises the food from the cooking oil and dumps the food into a container positioned at the food collection station at the end of the preselected cooking time.

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Garland, TX, United States of America

Joe R Powell