IT DEPENDS ON YOUR USAGE. Obvious one…
Your paint booth should have a recommended amount of hours per each filter. This is a rule of thumb since certain things can’t be controlled such as the quality of the outside air. We had a customer that was right next to a quarry and his pre-filters were clogged in a matter of weeks. They usually last months if not longer in most installations but his paint booth filters clogged fast due to the dirtiness of the air outside. Exhaust filters also can’t be guaranteed to last as long as the recommended hourly change. Maybe you spray body filler or something heavy that clogs them fast, maybe there was some sanded material that got into the filter. No way to tell.
The best answer is this. You should always change your paint booth filters when it reaches the hourly rate declared by the paint booth manufacturer. UNLESS you see a change in performance through the workspace. If your paint overspray is hanging around a little longer than you are used to, that is when you need to change your paint booth filters. By manufacturer’s recommendations or BEFORE depending on performance changes.
