Air duct assembly of air distribution system for a motor vehicle

An air distribution system for a motor vehicle having a windshield, a side glass disposed laterally outboard from the windshield, and a floor pan spaced vertically downward from the windshield, and the air distribution system comprising:

• a blower motor for producing a flow of air and an associated blower noise;
• an air duct assembly comprising:
• a first duct defining a first inlet fluidly connected to the blower motor and a first passage fluidly connected to the first inlet;
• a second duct defining a second passage separate from the first passage, with the first and second passages fluidly connected to a common outlet, such that air flows through the first and second passages and through the at least one common outlet to the windshield;
• a third duct defining a third passage separate from the first and second passages, with the second and third passages arranged to receive airflow in parallel from a common inlet and receiving air from the blower motor, with the common inlet separate from the first inlet, and the third passage is fluidly connected to a lateral outlet that is separate from the common outlet, with the lateral outlet flowing air to the side glass;
• and
• at least one acoustic baffle disposed within the second passage and configured to reduce a transmission of the blower noise through the second passage to the windshield;
• a first door coupled to the first duct, with the first door being movable between a closed position for blocking the flow of air into the first inlet and an open position for directing the flow of air from the blower motor into the first inlet;
• a first actuator coupled to the first door for moving the first door between the closed and open positions;
• a second door coupled to at least one of the second and third ducts, with second door being movable between a closed position for blocking the flow of air into the common inlet and an open position for directing the flow of air from the blower motor into the common inlet;
• a second actuator coupled to the second door for moving the second door between the closed and open positions;
• a user interface having at least one input device movable between a defrost mode, a side mode, and a combined defrost-side mode, with the user interface configured to generate a defrost signal, a side signal, and a combined defrost-side signal in response the input device being moved to an associated one of the defrost mode, the side mode, and the combined defrost-side mode;
• and
• a controller electrically coupled to the user interface, the first actuator, and the second actuator, with the controller configured to generate a defrost command signal, a side command signal, and a combined defrost-side command signal in response to the controller receiving an associated one of the defrost signal, the side signal, and the combined signal from the user interface;
• wherein the second actuator receives the defrost command signal from the controller and moves the second door to the open position in response to the second actuator receiving the defrost command signal from the controller.

A method of operating an air distribution system for a motor vehicle having a windshield, a side glass disposed laterally outboard from the windshield, and a side glass disposed laterally outboard from the windshield, with the air distribution system including a blower motor, with the air distribution system further including an air duct assembly having first, second, and third ducts that define an associated one of first, second, and third passages, with the second and third passages receiving airflow in parallel with one another, the assembly further including a common outlet associated with the first and second passages, a common inlet associated with the second and third passages, at least one acoustic baffle, a first door associated with the first passage, a first actuator coupled to the first door, a second door associated with the second and third passages, a second actuator coupled to the second door, a user interface having at least one input device, and a controller, the method comprising:

• producing, using the blower motor, a flow of air and an associated blower noise;
• moving at least one input device of a user interface to one of a defrost mode, a side mode, and a combined defrost-side mode;
• generating, using the user interface, one of a defrost signal, a side signal, and a combined signal in response the input device being moved to an associated one of the defrost mode, the side mode and the combined defrost-side mode;
• generating, with the controller, a defrost command signal, a side command signal, and a combined defrost-side command signal in response to the controller receiving an associated one of the defrost signal, the side signal, and the combined signal from the user interface;
• moving, using the first actuator, the first door to an open position in response to the first actuator receiving the defrost command signal from the controller;
• fluidly connecting the first duct and the blower motor with one another, in response to the first door being disposed in the open position;
• passing air from the blower motor through a first inlet, the first passage, and the common outlet toward the windshield in response to the first door being disposed in the open position;
• moving, using the second actuator, the second door to an open position, in response to the second actuator receiving one of the side command signal and the combined defrost-side command signal from the controller;
• fluidly connecting the second duct and the third duct with the blower motor, in response to the second door being disposed in the open position;
• passing air from the blower motor through the common inlet, the second passage, and the common outlet toward the windshield in response to the second door being disposed in the open position;
• reducing, using the at least one acoustic baffle, a transmission of the blower noise through the second passage to the windshield, in response to the second door being disposed in the open position;
• and
• passing air from the blower motor through the common inlet, the third passage, and a lateral outlet toward the side glass in response to the second door being disposed in the open position.