DILUTION VERSUS DISPLACEMENT VENTILATION - ENVIRONMENTAL-CONDITIONS IN A GARMENT SEWING PLANT

This paper- compares the practice of dilution ventilation (DILVENT), w hich ideally requires perfect mixing, with displacement ventilation (D ISPVENT), which involves fresh air displacing contaminated air without mixing. Keeping DILVENT as a reference the approach of intervention w as used to estimate the potential of DISPVENT for improving environmen tal conditions in a garment sewing plant. Air exchange efficiency of D ILVENT came to 49%. DISPVENT improved the efficiency to a level of 57% . At workstation level DISPVENT improved air renewal by a factor of 1. 3. DISPVENT reduced exposure to nonrespirable particles by a factor of 1.6-2.8. Exposure to respirable dust was reduced, but formaldehyde co ncentrations were left unaffected. DISPVENT improved conditions for co ntrol of bystander exposure by a factor of 7.7. DISPVENT improved ther mal conditions. Draft risk was reduced by a factor of 1.9. It is concl uded that DISPVENT has potential for improving environmental condition s in industry.