Cold start in auto
For a cold start the windscreen must first be de-iced or demisted. Following which, the cabin must be heated as quickly as possible. When the outside air and coolant are cold the fan speed must be adapted so that the air temperature after the heat exchanger is always as high as possible.
If the calculated temperature at head height for the driver is lower than the driver set using the ACC unit's temperature knob, and outside temperature is below approximately 6°C, then air distribution will depend on coolant temperature until defrost/floor position is adopted, see illustration.
As long as the calculated temperatures at head height for the front seat passenger and driver are lower then those set then the fan current will depend on coolant temperature and outside temperature, see illustration.
