Filtration for your paint booth is all about balance. Without balance, your booth will perform poorly and your operating costs will be higher than necessary. To achieve proper balance, filters must remove and hold contaminants but still allow for proper air flow.
 
Knowing When it's Time to Change Primary Filters 

Proper spray booth maintenance is critical. Delaying a filter change can result in a paint job that is ruined, causing significant additional costs such as buffing, color sanding, booth cleaning, etc. Moreover, because your booth is being used for rework, you won’t be able to move on to your next job or business opportunity. On an average, you should change out cross draft intake panel filters every one to three months and your downdraft ceiling filters should be changed out every six to twelve months. Any variation exists because each operating environment is different and paint hours tend to fluctuate. You need to change out your prefilters every two to four months. Proper prefilter maintenance will greatly extend the overall life of your more expensive final stage filters, like the downdraft ceiling filters. Change out your paint arrestors every one to two weeks.

Install Filters According to Air Flow

In order function properly, each filter needs to be installed in relationship to the direction of air flow. Paint arrestors should have the "open weave" side facing up into the painting chamber.  Overspray passes through this "open weave" and exits through the “skin backing”.  The "skin backing"  acts as the final filtration barrier before air departs from the paint arrestor or painting chamber. Paint overspray must enter the "open weave" first and exit through the tighter “skin backing” last. This will guarantee the proper depth loading, resulting in paint overspray particles building up evenly in the filter and thereby will serve to extend the filter’s operating life. Prefilters in pocket or bag form and exhaust / extraction filters should have the air enter into the pocket or bag configuration.
 
Using the Tacky Side as a Guide

Cross draft panel filters should always have the tacky side facing inside the spray booth, or in other words, the air should enter through the no-stick side and exit through the sticky or “tacky” side into the painting chamber.
Downdraft ceiling filters should be installed with the smooth backing or “mesh scrim” facing inside the spray booth, so that the air enters the more open, woven side and exits through the “mesh scrim” into the painting chamber. The smooth backing is designed to prevent filter fibers from breaking off and entering into the spray booth.
Prefilters in panel and pad form should have the tacky side facing inside the spray booth, or in other words, so that the air will enter through the non-sticky side and exit through the sticky side into the painting chamber. If no tackifier is applied to the prefilter, install it with the more open “weave” on the air entering side, and the tighter “weave on the air exiting side.