How to stop draft from gas fireplace?

A gas fireplace will not produce a draft like oil or wood burning fires because it is sealed. Drafting occurs when air moves through the chimney, pulling smoke with it and causing downdrafts in the room below. Sealing all joints where parts of your system meet should eliminate drafts; however, if you are experiencing problems try relocating your fireplace away from exterior walls (fireplace flue tiles allow for movement), installing an adjustable atmospheric vent to control airflow between rooms, adding dampers that close off unused fireplaces or even revising how existing vents were installed by using flexible aluminum ductwork rather than metal pipe which might be rusting due to condensation inside.