Abstract: A paint spray booth in which articles such as automobiles are sprayed while moving along a conveyor line passing through the working area of the booth. Air is moved from an area above the articles and downwardly around the articles for discharge through a plurality of longitudinally spaced vertical passages positioned along the center line of the booth and water supplied to a pan positioned beneath the articles is caused to cascade down the vertical passages for mixture with the spray-laden air so that the spray is transferred from the air to the water. As the air leaves the lower ends of the vertical passages, it is directed laterally to impact one side of the booth, thence abruptly upwardly to separate entrained water, and thence in the other lateral direction toward the other side of the booth for passage through the spaces defined between the vertical passages.