Patent ID: 7946505

Claim:
A vehicle environmental control system comprising: an interior rearview mirror assembly comprising a mirror support bracket and a mirror head, wherein the mirror support bracket has a mounting portion for releasable attachment to a mounting button adhesively attached to an interior surface of a vehicle windshield, and wherein the mirror head includes a pivot element that pivotally attaches to a pivot element of the mirror support bracket to pivotally attach the mirror head to the mirror support bracket at the windshield of the vehicle; a window temperature sensor assembly for sensing the temperature of the interior surface of the vehicle windshield, wherein the window temperature sensor assembly is included in the mirror support bracket of the interior rearview mirror assembly and wherein, when the mounting portion of the mirror support bracket mounts to the mounting button attached at the interior surface of the vehicle windshield, a temperature sensing surface of the window temperature sensor assembly is biased toward and into contact with the interior surface of the vehicle windshield so as to enhance maintaining thermal contact therewith; a humidity sensor assembly for sensing the ambient air humidity within the passenger cabin of the vehicle and a second temperature sensor assembly for sensing ambient temperature within the passenger cabin of the vehicle, wherein the humidity sensor assembly and the second temperature sensor assembly are disposed at a location within the passenger cabin of the vehicle external and distant from the mirror support bracket; a controller including a microprocessor and control logic operable to calculate an ambient dew point from the ambient air temperature and humidity as sensed by the second temperature sensor assembly and the humidity sensor assembly; and wherein, when the calculated ambient dew point is greater than the temperature at the interior surface of the windshield as sensed by the window temperature sensor assembly, a vehicle climate control system, responsive to the controller, is controlled to change the ambient air conditions in the vehicle passenger compartment.