طراحی اتاقک خنک و تاثیر آن بر شاخص تنش گرمایی در موضع کاری کارگران کوره در کارخانه شیمی معدنی همدان

Background and purpose: Heat is a common type of energy that is produced during industrial processes in many work places. Workers who are working in hot areas may be exposed to heat stress. The aim of this study is to evaluate the effect of a designed cool spot on reduction of Mean Radiation Temperature (MRT) and Wet Bulb Glob Temperature index (WBGT) on a group of furnace workers. Materials and methods: First, MRT and WBGT indices were measured to evaluate heat stress in a furnace workplace. Then a suitable cool spot was designed and constructed using a double layer insulator. Finally MRT and WBGT were measured and then compared between inside and outside cool spot simultaneously to ascertain the effect of cool spot on control of heat stress. Results: We found that mean MRT (43.8 ◦c) and mean WBGT index (29.5 ◦c) were both higher than threshold limit value (28 ◦c) recommended by ÂÇGÏH in workers' position. There was a significant difference between inside and outside cool spot in mean WBGT (22.8 vs. 29.6 ◦c) and mean MRT (28. 6 vs. 43.8 ◦c). Çonclusion: Furnace workers who are exposed to radiation and convection heat may suffer from heat stress and we found that a cool spot in workplace is a suitable and feasible method to reduce heat stress.