Field study of local exhaust hood performance.
Conroy LM; Prodans RS; Lachman M; Yu X; Perez S
Ventilation '94. Proceedings of the 4th International Symposium on Ventilation for Contaminant Control, September 5-9, 1994, Stockholm. 1994 Sep; :281-285
The results of a field study examining the performance of slot hoods used to exhaust vapor degreasers were reported. A total of 16 degreasers, 13 of which used trichloroethylene (79016) and three each using methyl-chloroform (71556), perchloroethylene (127184), and methylene-chloride (75092), were studied by measuring hourly solvent concentration levels at various distances from the degreasers and in the local exhaust duct and by measuring ventilation and crossdrafts near the local exhaust hood. A semiempirical model was used to predict capture efficiency. Overall predicted and measured capture efficiencies were generally in good agreement; however, poor agreement was seen between predicted and measured efficiencies in daily averages for each degreaser. Possible reasons for this finding were discussed. No relationship was identified between increasing hood flow and hood capture efficiency. The authors conclude that the American Conference of Governmental Industrial Hygienists recommended flow of 50 cubic feet per minute/square foot of tank surface is not adequate for all conditions and that data from ongoing wind tunnel studies may be useful for the validation of more complex models for the prediction of hood performance.
NIOSH-Grant; Control-technology; Training; Exhaust-hoods; Exhaust-systems; Exhaust-ventilation; Solvent-vapor-degreasing
Occupational and Environ Med University of Illinois 2035 W Taylor Street Chicago, Ill 60612
79-01-6; 71-55-6; 127-18-4; 75-09-2
Ventilation '94. Proceedings of the 4th International Symposium on Ventilation for Contaminant Control, September 5-9, 1994, Stockholm
University of Illinois at Chicago, Chicago, Illinois