This report describes the laboratory development and evaluation of an air canopy concept for longwall faces. The objective in an underground application would be to create a clear air zone along the face walkway by equipping the shields with water-powered scrubbers or other devices. Contaminated air would be extracted, cleaned, and reinjected into the breathing zone of face personnel. The concept was evaluated in a full-scale longwall test facility by equipping alternate shields with simulated air canopies. A variety of canopying configurations and airflow capacities were tested under different face ventilation situations to determine the quality and extent of the clean air zone developed by the canopy. The results revealed that even the most optimum configurations were unable to create a suitable clean air zone. Low effectiveness, coupled with high projected costs for underground application, showed the concept to be unfeasible, and further development effort was cancelled.