if the room has a window,a rectangular window fan can be used to exhaust out while the door of the room(slightly opened) can let fresh air in,or you can attach a door vent that will allow you to keep the door shut,i would use the vent option to maintain privacy,on the inside of the vent,an air filter can be taped to keep the dust out also(fresh air is about 300ppm's + CO2)....bonbon