Lennox Industries Inc.

Stephen A Walter

Marcus Troxell

Herman Marcus Thomas

John P Stachler

Roger C Hundt

Alan Edens Bennett

Richard A Mauk

Mark D Hess

Marcus W Troxell

Der-Kai Hung

Carlos O Chamorro

David Michael Wynnick

Harold Gene Havard

Mark W Olsen

Harold Gene Havard, Jr

Rosa Maria Leal

Joe R Powell

Mark G Beste

Erroll L Eaton

David Omlor

Steven C Brown

Brian R Hudson

Russell C Tharp

Brian Hudson

Alan E Bennett

A method and apparatus for cooling a supply of air is provided. A unit controller receives a cooling demand signal. In response to the cooling demand signal, the unit controller adjusts an economizer according to an economizing function. The economizing function is configured to achieve an initial free cooling target temperature as a discharge air temperature. The unit controller receives an additional cooling demand signal. In response to the additional cooling demand signal, the unit controller reduces the free cooling target temperature. The unit controller adjusts the economizer according to the economizing function, with the economizing function configured to achieve the reduced free cooling target temperature as the discharge air temperature. Additionally in response to the additional cooling demand signal, the unit controller signals a unit to perform mechanical cooling on a supply of air received from the economizer.

Economizer target temperature shift during mechanical cooling

In an embodiment, a method of testing a HVAC unit for a disconnected damper motor is provided. An outside air section of a damper assembly is closed and air is circulated through the unit. If a discharge air temperature is not substantially equal to a return air temperature, the damper motor is determined to be disconnected. Otherwise, an economizing function having a free cooling target temperature is started. An outside air temperature is compared to the free cooling target temperature. If the outside air temperature is less than the free cooling target temperature, the damper motor is determined to be disconnected if the damper motor has been commanded to fully open the outside air section. If the outside air temperature is not less than the free cooling target temperature, the damper motor is determined to be disconnected if a discharge air temperature is not substantially equal to an outside air temperature.

Detection of damper motor mechanically disconnected from damper assembly

An HVAC controller, a method of operating an HVAC controller and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a processor couplable to at least two refrigerant pressure sensors via separate data paths to receive input signals therefrom and further couplable to a compressor stage and a condenser fan to provide output signals thereto, and (2) memory coupled to the processor and storing a software program having program instructions capable of causing the processor to command the compressor stage or the condenser fan to turn on irrespective of a state of an input signal generated by either of the at least two refrigerant pressure sensors, and generate an error message at least partially depending upon whether or not a high pressure shutdown occurs after the processor commands the compressor stage or the fan to turn on.

Outdoor fan and indoor blower controller for heating, ventilation and air conditioning system and method of operation thereof

Systems and methods involve controlling a variable-speed blower in a heating, ventilating, and air conditioning (HVAC) system to ensure the setting of a blower-proving switch to confirm airflow in a building. In one instance, a method involves ramping up the variable-speed blower so that the associated static pressure reaches a making point pressure of the blower-proving switch and then reducing the power to a desired power level. The method may also include maintaining the power level above a breaking point pressure. Other systems and methods are presented.

Airflow-confirming HVAC systems and methods with variable speed blower

One aspect of the disclosure describes a controller for a heating, ventilation, and air conditioning (HVAC) unit. In one embodiment, the HVAC controller includes an interface and a processor. In this embodiment, the interface is configured to receive a delay originating signal. In one embodiment, the processor is configured to: (1) automatically generate an offset delay value for the HVAC unit upon receipt of the delay originating signal; (2) apply the offset delay value based on an offset enabled configurable parameter; and (3) delay starting identified components of the HVAC unit based on the offset delay value.

Staggered start-up HVAC system, a method for starting an HVAC unit and an HVAC controller configured for the same

An HVAC unit includes an HVAC motor and a system controller. The HVAC motor is coupled to a motor controller. The motor controller is configured to receive a command signal bearing a digitally encoded operating level of the HVAC motor. The system controller is coupled to the motor controller, and is configured to transmit the command signal to the motor controller. The system controller modulates the command signal with the digitally encoded operating level in response to a service demand.

Variable speed motor control method and apparatus

An HVAC controller, a method of starting a HVAC unit and a HVAC system are disclosed herein. In one embodiment, the HVAC controller includes: (1) an interface configured to receive a delay originating signal and (2) a processor configured to automatically generate an offset delay value for the HVAC unit upon receipt of the delay originating signal and delay starting identified components of the HVAC unit based on the offset delay value.

An HVAC controller, a method of operating an HVAC controller and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a processor couplable to at least two refrigerant pressure sensors via separate data paths to receive input signals therefrom and further couplable to a compressor stage and a condenser fan to provide output signals thereto and (2) memory coupled to the processor and configured to store a software program capable of causing the processor to command the compressor stage and the condenser fan to turn on irrespective of a state of an input signal generated by either of the at least two refrigerant pressure sensors and generate alternative error messages at least partially depending upon whether or not a high pressure shutdown occurs after the processor commands the compressor stage and the fan to turn on.

An airflow managing system for monitoring airflow of a HVAC system, a HVAC system and a method of monitoring the airflow in a HVAC system is provided. In one embodiment, the airflow managing system includes: (1) an air pressure sensor configured to obtain an air pressure measurement directly from a scroll of an air blower of the HVAC system and (2) a HVAC controller configured to determine an airflow rate for the HVAC system based on the air pressure measurement and corresponding parameters associated with the air blower.

Airflow managing system, a method of monitoring the airflow in an HVAC system and a HVAC system

An HVAC system includes a blower motor and a variable speed motor drive. The variable speed motor drive is configured to receive line power and provide modulated power to the motor. The blower motor is configured to produce airflow in response to the modulated power. A unit controller is configured to bypass the variable speed motor drive to provide the line power directly to the blower motor in the event that a measured airflow is less than a predetermined value.

Automatic variable speed motor drive bypass

An HVAC controller, a method of operating a HVAC unit and a HVAC system are disclosed herein. In one embodiment, the HVAC controller includes: (1) an interface configured to receive both a latent cooling demand and a sensible cooling demand and (2) a processor configured to direct both a dehumidification function and a cooling function when simultaneously processing both the latent cooling demand and the sensible cooling demand, the dehumidification function based on an operating capacity of an indoor air blower system.

HVAC system with automated blower capacity dehumidification, a HVAC controller therefor and a method of operation thereof

An HVAC controller, a method of operating a constant air volume (CAV) HVAC unit and a CAV HVAC system are disclosed herein. In one embodiment, the HVAC controller includes: (1) an interface configured to receive both a latent cooling demand and a sensible cooling demand and (2) a processor configured to direct both a dehumidification function and a discharge air temperature control function for a CAV HVAC system employing the latent cooling demand and the sensible cooling demand.

Constant air volume HVAC system with a dehumidification function and discharge air temperature control, an HVAC controller therefor and a method of operation thereof

Growing community of inventors

Flower Mound, TX, United States of America

Stephen A Walter