Lennox Industries Inc.

Lennox International Inc.

Patric Ananda Balan Thobias

Rakesh Goel

Siddarth Rajan

Shiliang Wang

Amit Parsai

Abdul Rehman

Edward Robinson

Sangameshwaran Sadhasivam

Vinoth Kumar Settu

Prabhu Prakasam

Dilbag Singh Gill

Vickey Bhardwaj

A method operating an HVAC system is provided. The method includes receiving a concentration of refrigerant. The method includes operating the HVAC system in a leak diagnostic mode if the concentration exceeds a gas concentration threshold. The method includes turning on a compressor to compress the refrigerant. The method includes receiving a first saturated liquid temperature and a first subcooled liquid temperature, and determining a first subcooled value based on the difference. The method includes turning off the compressor for a duration, and turning on the compressor after the duration has elapsed. The method includes receiving a second saturated liquid temperature and a second subcooled liquid temperature, and determining a second subcooled value based on the difference. The method includes determining that the first refrigerant circuit includes a refrigerant leak if the second subcooled value or the first subcooled value exceeds a subcooled threshold value.

System and method for detecting a refrigerant leak in an HVAC system using a subcooling temperature

In an embodiment, a blower for a heating, ventilation, and air conditioning system includes a blower wheel and a housing. The blower wheel includes backward-curved blades configured to rotate in a rotational plane. The housing forms an at least hexagonal cross-section around at least a portion of the rotational plane, where the blower wheel is positioned within the housing such that there exists a first distance and a second distance. The first distance is measured radially outward from a center of the blower wheel to a first side of the at least hexagonal cross-section. The second distance is measured radially outward from the center of the blower wheel to a second side of the at least hexagonal cross-section. The second distance forms a an acute angle with the first distance. The first distance and the second distance are unequal and less than a diameter of the blower wheel.

High-performance housings for backward-curved blowers

An HVAC system includes a compressor, condenser, and evaporator. A sensor measures a value associated with the refrigerant in the condenser or the evaporator, and a controller is communicatively coupled to the compressor and the sensor. The controller determines, based on an operational history the compressor, that pre-requisite criteria are satisfied for entering a sensor validation mode. After determining the pre-requisite criteria are satisfied, an initial sensor measurement value is determined. Following determining the initial sensor measurement value, the compressor is operated according to a sensor-validation mode. Following operating the compressor according to the sensor-validation mode for at least a minimum time, a current sensor measurement value is determined. The controller determines whether validation criteria are satisfied for the current sensor value. In response to determining that the validation criteria are satisfied, the controller determines that the sensor is validated.

Sensor validation

A method of operating an HVAC system includes compressing a working fluid using a compressor, removing heat from the working fluid using a condenser, removing pressure from the working fluid using an expansion valve, and transferring heat between airflow contacting an outer surface of one or more coils in an evaporator and the working fluid passing through the one or more coils. The method further includes detecting a leak of the working fluid using a leak detection sensor. The method further includes transporting at least a portion of the working fluid to a storage container and storing the working fluid in the storage container.

Systems and methods for refrigerant leak mitigation

A blower of an HVAC system includes an air inlet, an air outlet, a blower wheel with blades, a motor operable to cause the blower wheel to rotate, and a blower housing within which the blower wheel is positioned. The blower housing includes a top panel, a bottom panel, and a connecting panel. The top panel and the bottom panel are connected to the connecting panel. The top panel includes a curved edge extending from a bottom edge of the connecting panel to a top edge of the connecting panel. An expansion angle of the curved edge of the top panel changes as a function of position along the curved edge of the top panel. The bottom panel may have a shape corresponding to a mirror image to that of the top panel.

Housing for forward curved blower

In an embodiment, a blower for a heating, ventilation, and air conditioning system includes a blower wheel and a housing. The blower wheel includes backward-curved blades configured to rotate in a rotational plane. The housing forms an at least hexagonal cross- section around at least a portion of the rotational plane, where the blower wheel is positioned within the housing such that there exists a first distance and a second distance. The first distance is measured radially outward from a center of the blower wheel to a first side of the at least hexagonal cross-section. The second distance is measured radially outward from the center of the blower wheel to a second side of the at least hexagonal cross-section. The second distance forms a an acute angle with the first distance. The first distance and the second distance are unequal and less than a diameter of the blower wheel.

A blower for an HVAC system, the blower includes a housing with an intake and an outlet, a fan or blower wheel disposed within the housing and configured to draw air into the housing via the intake and to exhaust air from the housing through the outlet, and an adjustable cutoff plate configured to be moved between at least a first position defining a first cutoff angle and a second position defining a second cutoff angle.

Blower with adjustable cutoff plate

An HVAC system includes an evaporator, a first sensor coupled to the evaporator at a first position, and a second sensor operably coupled to the evaporator at a second position. The first sensor monitors a first temperature of the refrigerant flowing in the evaporator at the first position, which is adjacent to the evaporator inlet. The second sensor monitors a second temperature of the refrigerant flowing in the evaporator at the second position, which is downstream from the first position. The system includes a controller, which receives a first signal corresponding to the first temperature and a second signal corresponding to the second temperature. The controller determines, based on the received signals, a temperature difference between the second temperature and the first temperature. In response to determining that the temperature difference is greater than a predefined threshold value, the controller determines that a loss of charge has occurred.

Detecting loss of charge in HVAC systems

A compressor system includes a first compressor and a second compressor. A suction equalization line fluidly couples the first compressor and the second compressor. A first branch suction line is fluidly coupled to the first compressor and a second branch suction line is fluidly coupled to the second compressor. A main suction line is fluidly coupled to the first branch suction line and the second branch suction line. An obstruction device is disposed in at least one of the first branch suction line and the second branch suction line. Responsive to deactivation of at least one of the first compressor and the second compressor, the obstruction device is at least partially closed thereby causing prescribed liquid levels in the first compressor and the second compressor during partial-load operation.

Method and apparatus for balanced fluid distribution in tandem-compressor systems

A compressor system includes at least two compressors. A suction equalizing tube fluidly couples the at least two compressors. A plumbing assembly fluidly couples to the first compressor and the second compressor. The plumbing assembly comprises an outlet to each compressor of the at least two compressors. A pressure differential between the at least two compressors is created so as to facilitate maintenance of a desired fluid level in the at least two compressors.

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Pondicherry, India

Patric Ananda Balan Thobias