The diffuser on the left is a normal office type diffuser which induces a lot of air to rise vertically from the floor towards the ceiling. The rising induced air has the potential for carrying a lot of dust upwards which is then spread throughout the room with the air supply. This type of diffuser readily spreads contaminants in the room and should be avoided.
The preferred type of diffuser for cleanroom applications is the swirl diffuser, or perforated plate diffuser. These types do not promote the spread of dust within the room.
