Thermal Comfort Assessment: A Case Study at Malaysian Automotive Industry

Problem statement: Thermal comfort has a great influence on the productivity and satisfaction of indoor building occupants. The exposure to excessive heat during work may cause discomfort and contributed to low productivity among workers. Malaysia known with its hot and humid weather where in most of the survey study published indicated that workers in Malaysia automotive industries had exposed to excessive temperature while working. The study investigated the thermal comfort level experienced by workers at Malaysian automotive industry. Approach: The study had been conducted at one automotive parts assembly factory in Malaysia. The human subjects for the study constitute operators at tire receiving section of the factory. The environment examined was the relative humidity (%), WBGT, air temperature and radiant temperature (°C) of the surrounding workstation area. The environmental factors were measured using Babuc apparatus, which is capable to measure simultaneously those mentioned environmental factors. The time series data of fluctuating level of factors were plotted to identify the significant changes of factors. Then thermal comfort of the workers was assessed by using ASHRAE thermal sensation scale by using Predicted Mean Vote (PMV). Further Predicted Percentage Dissatisfied (PPD) was used to estimate the thermal comfort satisfaction of the occupant. Finally the PPD versus PMV were plotted to present the thermal comfort scenario of workers involved in related workstation. Results: The trend of relative humidity curve from the graph also indicated the increasing level of discomfort. The radiant temperature observed seems consistent during the study while there was decreasing of WBGT start from afternoon due to the rain. The study revealed that the PPD value of 54% of the workers population at the workstation are likely to be satisfied with thermal comfort at this station while the PMV index from ASHRAE indicated the value 1.07-1.41. Conclusion: The empirical study from the PPD and PMV index indicated that workers working at this were influenced by the heat. The less of PPD value from 80% of the population satisfied with the thermal comfort showed the environment factors that were not good for worker while the PMV index showed the area of work is slightly warm.