Abstract: A method for controlling a vehicle HVAC system to automatically defog a windshield glass and to prevent fogging or condensation of the windshield glass. In-cabin air temperature and relative humidity are measured and used to determine a dewpoint. Further, ambient or outside temperature is measured. If windshield wipers are being used or if the cabin air temperature is less than a predetermined temperature, the ambient air temperature value is used as a glass temperature, otherwise the glass temperature is determined from the ambient air temperature and vehicle speed. A fog margin, which is a measure of the likelihood of fog formation, is based upon the difference between dewpoint and the windshield glass temperature. The fog margin is used to control the HVAC system to anticipate and respond to potential fogging conditions.

Abstract: In a vehicular air conditioning apparatus, a connection duct connects a first blower unit having a first blower fan to a side of a casing forming air passages, whereas a second blower unit having a second blower fan, different from the first blower unit, is connected to a lower portion of the casing. By driving the first blower fan and second blower fan simultaneously, air is supplied to a vehicle compartment from the first blower unit and the second blower unit through inside the casing. A controller controls the driving of the first blower fan and the second blower fan.

Abstract: An HVAC system for a vehicle includes a housing, a front HVAC unit with a front blower, and rear HVAC unit with a rear blower. The front and rear HVAC units are housed in the housing. The front blower generates an airflow through a front airflow path and the rear blower generates an airflow through a rear airflow path. A separating wall separates the front airflow path from the rear airflow path. The HVAC system further includes an evaporator with a first portion and a second portion. When the rear blower is switched to an OFF position, the rear HVAC unit automatically operates the rear blower at a minimum voltage so as to continue to generate airflow through the second portion of the evaporator.

Abstract: In a vehicular air conditioning apparatus, a connection duct connects a first blower unit having a first blower fan to a side of a casing forming air passages, whereas a second blower unit having a second blower fan, different from the first blower unit, is connected to a lower portion of the casing. By driving the first blower fan and second blower fan simultaneously, air is supplied to a vehicle compartment from the first blower unit and the second blower unit through inside the casing. A controller controls the driving of the first blower fan and the second blower fan.

Abstract: A method for controlling a vehicle HVAC system to automatically defog a window and to prevent fogging or condensation of the window. In-cabin air temperature and relative humidity are used to determine a dewpoint. Further, ambient or outside air temperature is measured. Window glass temperature is either estimated/calculated or can be measured. A fog margin, which is based upon the difference between the dewpoint and the window temperature, is calculated. When the ambient air temperature is below a predetermined temperature, a corrected fog margin is substituted for the calculated fog margin. When this occurs, the controller operates a fan at a reduced voltage, and hence at a reduced speed, as compared to if the controller used the calculated fog margin. Using the corrected fog margin prevents a vehicle user from being exposed to excessive fan noise or air currents during low or cold ambient air temperatures.

Abstract: An HVAC system for a vehicle includes a housing, a front HVAC unit with a front blower, and rear HVAC unit with a rear blower. The front and rear HVAC units are housed in the housing. The front blower generates an airflow through a front airflow path and the rear blower generates an airflow through a rear airflow path. A separating wall separates the front airflow path from the rear airflow path. The HVAC system further includes an evaporator with a first portion and a second portion. When the rear blower is switched to an OFF position, the rear HVAC unit automatically operates the rear blower at a minimum voltage so as to continue to generate airflow through the second portion of the evaporator.

Abstract: A method for controlling a vehicle HVAC system to automatically defog a window and to prevent fogging or condensation of the window. In-cabin air temperature and relative humidity are used to determine a dewpoint. Further, ambient or outside air temperature is measured. Window glass temperature is either estimated/calculated or can be measured. A fog margin, which is based upon the difference between the dewpoint and the window temperature, is calculated. When the ambient air temperature is below a predetermined temperature, a corrected fog margin is substituted for the calculated fog margin. When this occurs, the controller operates a fan at a reduced voltage, and hence at a reduced speed, as compared to if the controller used the calculated fog margin. Using the corrected fog margin prevents a vehicle user from being exposed to excessive fan noise or air currents during low or cold ambient air temperatures.

Abstract: A method for controlling a vehicle HVAC system to automatically defog a windshield glass and to prevent fogging or condensation of the windshield glass. In-cabin air temperature and relative humidity are measured and used to determine a dewpoint. Further, ambient or outside temperature is measured. If windshield wipers are being used or if the cabin air temperature is less than a predetermined temperature, the ambient air temperature value is used as a glass temperature, otherwise the glass temperature is determined from the ambient air temperature and vehicle speed. A fog margin, which is a measure of the likelihood of fog formation, is based upon the difference between dewpoint and the windshield glass temperature. The fog margin is used to control the HVAC system to anticipate and respond to potential fogging conditions.

Abstract: A blower system and method of operation for a vehicle air conditioning system, including a blower case for receiving air to be circulated into a vehicle cabin, with first and second dampers, for varying between a recirculation position for recirculating vehicle cabin air and a fresh position for introduction of fresh air from outside the vehicle. If a calculated outlet temperature is below a first temperature, a control system opens both dampers to a recirculation position. If the calculated outlet temperature is between the first temperature and a higher second temperature, the control system opens either the first or second damper to a fresh position, and opens the other damper to a recirculation position or the fresh position based upon relative humidity and vehicle speed. If the calculated outlet temperature is higher than the second temperature, the first and second dampers are both opened to the fresh position.

Abstract: A method and system for controlling a cooling fan that cooperates with an air conditioning condenser in a vehicle. The present embodiments include steps and corresponding implementations for determining a speed of the vehicle, determining a discharge pressure of the air conditioning condenser, determining an ambient temperature of air surrounding the vehicle and determining an outlet temperature of a vehicle air conditioning system. The cooling fan is operated in one or more desired fan speed modes corresponding to one or more respective discharge pressure ranges. The fan speed modes are a function of vehicle speed and one or more of ambient temperature, outlet temperature, and discharge pressure.

Abstract: A method and system for controlling a cooling fan that cooperates with an air conditioning condenser in a vehicle. The present embodiments include steps and corresponding implementations for determining a speed of the vehicle, determining a discharge pressure of the air conditioning condenser, determining an ambient temperature of air surrounding the vehicle and determining an outlet temperature of a vehicle air conditioning system. The cooling fan is operated in one or more desired fan speed modes corresponding to one or more respective discharge pressure ranges. The fan speed modes are a function of vehicle speed and one or more of ambient temperature, outlet temperature, and discharge pressure.

Abstract: A blower system and method of operation are disclosed for a vehicle air conditioning system, including a blower case for receiving air to be circulated into a vehicle cabin, with first and second dampers, each for selectively varying between a recirculation position for recirculating vehicle cabin air into the blower case and a fresh position for introduction of fresh air from outside the vehicle into the blower case. An outlet temperature is calculated for a vehicle air conditioning system. A control system is provided for controlling the damper positions based on the calculated outlet temperature. If the calculated outlet temperature is below a first temperature, the control system opens both dampers to a recirculation position so as to recirculate vehicle cabin air into the blower case.

Abstract: A blower system and method of operation for a vehicle air conditioning system, including a blower case for receiving air to be circulated into a vehicle cabin, with first and second dampers, for varying between a recirculation position for recirculating vehicle cabin air and a fresh position for introduction of fresh air from outside the vehicle. If a calculated outlet temperature is below a first temperature, a control system opens both dampers to a recirculation position. If the calculated outlet temperature is between the first temperature and a higher second temperature, the control system opens either the first or second damper to a fresh position, and opens the other damper to a recirculation position or the fresh position based upon relative humidity and vehicle speed. If the calculated outlet temperature is higher than the second temperature, the first and second dampers are both opened to the fresh position.