Your paint spray booth is a valuable component of your shop. While it’s not complicated to operate, proper use is crucial to achieving the best results. Spray booths use a combination of air intake and extraction for removing fumes, keeping the user safe. Airflow also keeps paint over spray in check, giving you high-quality results. When you’re inside automotive spray booths, the exhaust system must draw substantial amounts of air out of the booth and exhaust it outside the shop to operate properly. The exhausted air must be replaced by an equal amount of fresh air.

Negative and Positive Pressure

The exhaust fan, when operating normally, creates a “negative” air pressure inside the booth, taking more air out than is being put in. When the door is opened, negative air pressure causes the booth to suck in as much air as possible, bringing dirt and debris inside. To counter negative pressure, an Air Makeup Unit is used. If the AMU brings more air into the booth than is being extracted, the booth will have a “positive” air pressure. When the door is opened, it pushes dust and debris away from the interior, keeping it out of the workspace. Controlling this airflow is critical to efficient operation of the booth. It’s important to ensure the proper flow of air over the material being painted to effectively remove over spray, ensuring a professional finish.

Air Flow Fans

Air intake and exhaust are controlled by two different types of fans. The exhaust fan uses a propeller type of fan designed to pull air from the unit. The fan that draws air into the booth is a blower fan. It is designed to push air into the booth. Controlling the airflow and pressure is a balance between these two fans. When a booth is considered “balanced,” the same amount of air is being inputted and exhausted. If the door is opened, the pressure goes negative and debris can be sucked into the booth. When more air is being drawn in than exhausted, it creates positive pressure, which pushes air away when the door is opened. This keeps the workspace cleaner. Controlling the airflow changes the way that you paint. Ideally, you can control a number of factors like temperature, time, and booth pressure to achieve the results you need based on the job.