Indoor air pollution can make workplaces worse. Mechanical or natural ventilation systems, impelled by thermal gradients or wind pressure, can reduce indoor pollution levels by introducing adequate indoor air changes; moreover airflows can drag pollutant gases both from the external environment and among internal spaces. An air curtain system can reduce the airflow through openings of adjoining spaces and, as a consequence, can realize a system to control pollution. Flux reduction, gaseous and particulate pollutant control and human exposure time produced by air curtain ventilation systems are investigated by theoretical and advanced CFD analysis in order to improve their design by general guidelines.