I use two air filters which seems to work pretty much to clean room conditions, especially if you keep the room itself clean. Keeping the amount of fabric in the room (carpets, curtains etc) to a minimum is a big help and don't forget what comes off your own clothes. A friend once told me that she did her lab work naked to get round that problem. I have never gone to that extreme, but some artificial fibers seem less dusty than natural fibre (it might be the static holding the dust on). I have heard that an air ionizer can help, but have never tried.