To achieve optimum swine performance, producer understanding of environmental control systems in mechanically or naturally ventilated facilities is extremely important. A ventilation workshop: "Managing Your Unseen Employee: The Ventilation System" was established. The primary objective of the training was to give swine producers and managers enough quality information so they could go back to their operations and properly assess their own ventilation systems and make appropriate adjustments as needed. The training workthops were established to be a multi-state and multi-disciplinary effort between South Dakota, Nebraska, Iowa and Minnesota universities. Ag engineers and animal scientists from each state participated in developing the workshop materials and delivery of the program. Four basic needs emerged that would enhance program delivery. These needs included basic environmental factors and their effects on pigs, ventilation system design principles, trouble-shooting ventilation problems, and hands-on demonstrations of instrumentation and ventilation equipment. A 1.8 m by 2.4 m by 2.4 m mobile ventilation room was used for the hands-on training. The mobile ventilation room was equipped with two variable-speed. 30-centimeter fans and one 30-cm, single-speed fan; a four-stage controller; and three types of air inlets. From 2002 to 2007. over 1000 people producing over 20 million pigs participated in more than 60 workshops. The backgrounds of participants included managers, feed consultants. extension educators, and veterinarians. Key points gained by producers included proper ventilation settings, trouble-shooting techniques, temperature control, and the effects of static pressure on airflow.