
The widespread use of low solvent, water-borne base coats and paints means that humidity control is essential in spray booths. Relative humidity (RH) levels as high as 65-75% are often used for water-based paints, delivering consistent spray quality by preventing aerosol evaporation and pigment agglomeration, consistent deposition rates and preventing premature drying. Spray or evaporative humidifiers are commonly used for their economy, with steam also used in smaller applications.
High RH is undesirable in the drying process, of course, but when metal components leave the oven the local environment in sanding, repair and inspection areas can be hot and dry. This leads to worker discomfort and electrostatic build-up, drawing dust to the component. Using a humidifier as an evaporative cooler combats both problems simultaneously, both cooling the air for a safer, more productive environment and raising the RH to discharge electrostatic. An inspection deck at 35°C/15%RH can be cooled to 22°C/65%RH economically and effectively using this principle.