Abstract: An apparatus and method is provided for regulating the climate in a spray booth. The spray booth comprises a chamber for housing articles during spray application of a coating material to the articles and an air circulation system for supplying either ambient air or recirculation air to the chamber. The chamber has an outlet for exhausting a contaminated mixture of chamber air and coating material overspray from the chamber. The spray booth further includes a liquid filter for washing the contaminated mixture exhausted through the chamber outlet to wash the coating material overspray out of the mixture. The air circulation system of the improved spray booth includes a system for controlling the temperature of the air supplied to the chamber to regulate the relative humidity of the air in the chamber.