Air Conditioner

Does the central AC and the bedroom AC draw air from outside or just circulate inside air? We are getting a sewer odor in our Big Horn every time we run either AC. Sometimes it is worse than others. We are holding water in our toilet and do not notice any ordor from the sinks. Just when the AC is running?

No it recirculates the air. but might be creating a vacuum pulling air from the attic, is my guess. i have the same problem. just installed a unit in the bedroom and its doing the same thing. going to try and seal off the intake so it only pulls air from the a/c filters in the bedroom and not the attic.