i know the air conditioner pulls air from inside the room and cools it, then returns the cool air to the room...but does it also pull any air from outside?
"As a very generalisation, window units and 'through the wall' units do not draw air from outside unless they have a specific control for drawing in outside air. Any outside air leaking in, or being purposely let in, will lower the efficiency of the system.
Very few homes are anywhere near 'airtight' closing the windows and doors will keep out some odours but not all. Doors are particularly difficult to get anywhere near airtight. Then look at all the other openings you may have, dryer vents, exhaust vents from bathrooms and laundries, range hoods exhausting to outside, all these allow air and odours in."