Buzzing in dash

Hi,

Does anyone know what the buzzing sound is in the dash of my 740il E38 when a door opens?

It almost sounds like an electric fan or something. The key doesn't have to be in the ignition, but whenever a door is opened the buzzing starts up!!!

I know this is normal, but I would just like to know what it is.

Thank you

Never mind, its the climate control fan.


Does anyone know why it operates after the engine has been switched and the occupants have left the car? What's the point of having it run for 16 minutes?


Thanks

i know i can hear something in the HVAC system closing or something, like the outside air vent or something when i take the key out. maybe thats what i'm hearing? i've wondered myself.