Abstract: A paint spray booth utilizes an exhaust system extending longitudinally along the path of the articles to be painted having an adjustment mechanism for varying the width of the exhaust inlets extending longitudinally for substantially the entire length of the air exhaust element and a downwardly slanting bottom surface of the exhaust elements for yielding powder overspray of uniform density to a filter media. Adjusting the width of the longitudinally extending exhaust inlet spreads an adjustable pressure drop over the slot opening. Adjusting the velocity of air flow through the exhaust elements substantially avoids powder paint build-up at the exhaust inlet. The slanted configuration of the exhaust elements, in conjunction with the adjustment mechanism, improves uniformity of filter life by providing a substantially even distribution of powder overspray to a filter media.