Dual aircondition failiure?

Thanks for your answer, but can you give e a few more details? Where is this blend door part? Can i fix it my self or i have to see a mecanic? Thank you. Later Edit: i found out that the the problem was the freon from the aircondition. If you don't have enough, the car uses it just for half of the AC vents. So switch to economic mode and the problem is solved for the winter. when the sumer comes, just refil with freon and you're done.