Notice that in the draw-thru system, the air is drawn through a filter door or wall. This is usually the product entry door because it has sufficient area to allow for good filtration. It is an important addition to a booth to add a filter door (as opposed to using an open front booth) because air carrying dust and dirt particles is filtered prior to entering the painting chamber removing most of the cause of imperfections. Filters will also smooth out the airflow by diffusing the air.

Graphic by permission of Ron Joesph & Associates, Inc.