Abstract
The energy crisis is providing an incentive for industry in the U. S. to conserve fuel. A major consideration is the recirculation of Industrial exhaust air to reduce energy consumption in heating or cooling work place air. Although there is a history of literature on the subject, design criteria for recirculation systems are very limited. Primary system components are air cleaning equipment and monitoring/alarm equipment. If feasibility of recirculation is established, air cleaning equipment must be selected to remove specific contaminants properly. Types of air cleaning equipment are reviewed from the standpoint of collection mechanism, equipment configuration, performance capability, and applicability to recirculation. Monitoring equipment requires significant development work to assist in safeguarding re-circulation systems and to provide worker protection.