Every paint booth should have an air makeup unit (AMU)—but not every booth needs one. For example, non-pressurized booths do not require an AMU. However, having a booth equipped with an AMU can greatly benefit your finishing process.
An air makeup unit is an HVAC solution that replaces the air being brought out of a booth from exhaust fans with clean, fresh air. Its purpose is to help keep proper ventilation and air quality within a cabin for ideal spraying conditions and painter’s health. It also has heating and cooling capabilities, although cooling features are more commonly used within the aerospace industry. Some AMUs even have complete climate and humidity control.
Whether your booth is equipped with an AMU or not, it’s valuable to understand the role one plays in the finishing process. There are two ways an AMU is used: in paint mode and the curing process.
In paint mode, painting causes contaminants within a booth’s air. In fact, about half of the paint being sprayed within a booth sticks to the intended object while the rest remains airborne. For this reason, 100% fresh air is ideal for paint mode rather than recirculated air. An AMU that delivers fresh air will bring in one part of air to the booth for every one part of contaminated air that is leaving the booth.
After paint mode, cabins are heated at elevated temperatures for the curing process. During the curing process, no spraying occurs, which makes it an ideal situation for recirculation. A paint booth that is designed to support an AMU that recirculates air will use a lot less energy to achieve the necessary high temps for curing. An AMU that utilizes recirculation will deliver about 90% reused air and 10% fresh air within a booth.
There are generally two different types of air makeup units for refinishing: indirect and direct fire burners.
Accudraft is a leading paint booth manufacturer with nearly 45 years in the industry—meaning we’ve had decades to transform and evolve our finishing system technology. As the industries we serve continue to grow, our equipment grows with their needs. Every air makeup unit we install is equipped with a control panel that automates pressure controls, temperatures, and modes. Painter’s no longer needs to manually switch between paint and curing modes—the CPU makes all the necessary adjustments.
To learn more about upgrading or installing an air makeup unit, contact Accudraft online.