Question

درجه ی کولر رو کم کن

Answer 1

Turn down the AC or air con: it is used if you want to make it colder and it's warm inside.Conversely, turn up the AC means it's too cold inside. 

Answer 2

Please lower the AC's cooling level.

Please set the AC's thermometer to (a) lower scale. / degree. / level.

Answer 3

Could you turn the AC down please, it's freezing in here!