Air compressors are more than the heart of most automotive shops — they’re also the brain and central nervous system, powering everything from grinders and sanders to cutters and welders.
One of the most integral roles that compressors play in the shop is auto body painting.
Given that air compressor use accounts for 50-70% of a typical body shop’s monthly electric bill, boosting energy efficiency should be a topline priority for any auto servicing shop.
Rotary screw compressors use dual nesting rotors that revolve to compress intake air. Unfortunately, screw designs suffer from a fundamental flaw: “blow holes” that form between the rotors and the cylinder case when rotors are positioned at a specific angle. The effect is leaks that releases air back to the intake, resulting in continual, unavoidable energy losses.
Since auto body paint guns require high air volume (CFM), these energy losses become especially costly for owners, making this kind of compressor impractical for auto body shops.
Rotary vane air compressors, on the other hand, employ sliding vanes that maintain constant contact with the stator to create a near-perfect seal on compression chambers. In combination with rotary vane compressors’ lower residual heat losses, its tightly-sealed chambers boost energy efficiency by reducing leakage and requiring less electricity. As a result, rotary vane compressors enjoy lower operating costs and improved durability.
Rotary vane compressors are not only more efficient, but also require less maintenance than screw models.
To compensate for the “blow hole” effect, screw compressors rotors operate at higher speeds. While this reduces the time that the blow hole stays open, it also hastens wear, reduces energy-efficiency, increases axial thrust, and demands the use of expensive roller bearings that require frequent replacement.
As many as seven sets of bearings are required in screw compressors because of axial thrust, and require costly replacement or complete rebuilding of air ends after 35,000 to 50,000 hours. Because rotary vane compressors are primarily in-line direct drive there is no axial thrust so they don’t rely on bearings but instead two simple bushings.
Rotary screw compressors are also more likely to suffer from oil carryover — a condition in which lubricants make their way into parts of the machine where they aren’t meant to go. Oil carryover is an auto painter’s worst nightmare, can inhibit proper filtration, contaminate air discharge piping, or damage pneumatic tools or equipment operated by the compressed air system. Oil carryover in rotary vane compressors tends to be much lower, reducing wear on the machine, enabling fewer filter replacements, and saving oil change costs.
For auto body professionals, contaminant-free air is critical to quality assurance in painting operations.
Strict EPA regulations limiting volatile organic compound (VOC) levels in paint have made waterborne paints the industry standard since they tend to have lower VOC levels than their solvent-based counterparts. Unfortunately, they are also more sensitive to moisture and oil contamination, which reduces air purity and can inhibit paint adhesion.
Rotary vane technology is ideal for applications using waterborne paints. With properly sized desiccant dryers and inline filtration systems a rotary vane compressor, paired with oil carryover of less than 3 ppm, and less than 3% relative humidity enables the production of high quality, clean dry air. Thanks to these advantages, rotary vane compressors can promise high quality airflow for superior auto body painting.
Automotive repair shops specializing in painting services can rely on rotary vane technology to raise their painting quality standards. However, as we’ve shown, your compressor can (and should!) do more than raise your air purity levels. Investing in a rotary vane compressor creates incredible energy and time savings, reduces maintenance demands, and guarantees a reliable source of contaminant-free air for all auto body shop applications.
At Mattei, we’ve been the industry leaders in air compression for over two decades. That’s why we’re the brand trusted by Ford, Porsche, Lamborghini, TESLA, and most automotive dealers. Choose from a wide selection of Mattei rotary vane compressors to capitalize on the unmatched efficiency, purity standards, and durability that we’re known for.