IMPROVING THERMAL COMFORT OF WORKERS IN THE FINISHED GOOD WAREHOUSE BASED ON PREDICTED MEAN VOTE (PMV) USING COMPUTATIONAL FLUID DYNAMICS (CFD)

The hot and humid tropical physical work environment is one of the factors causing the high heat stress and potentially influence greatly to the worker performance in a company. The aim of this paper is to optimise the workers thermal comfort based on personal and environmental condition in finished product warehouse on tropical climate. The first step of the research is a study of literature on Predicted Mean Vote (PMV), Computational Fluid Dynamic (CFD) and human thermal comfort. The researchers conducted data collection on thermal comfort outside and inside the warehouse on the existing conditions, namely; temperature, activity type, clothing, air velocity, Mean Radiant Temperature (MRT), and relative humidity. Existing data are used to calculate PMV and Predicted Percentage of Dissatisfied (PPD) at 44 workers activity points with PMV results in the range of +2.27 to +2.61 with average + 2.38 (warm) and PPD in the range of 88.7% to 95.4% with average 94.41%. The CFD simulation was employed to illustrate the contour plot of temperature distribution, relative humidity and wind velocity on existing and after improvement conditions. The simulation tests show that temperature and air speed were the important factors of improving PMV in this problem. Potentials due to temperature differences in outdoor and indoor at 4°C became the basis for the improvement of the warehouse building. It was conducted by installing 33 exhaust fans with a capacity type of 3610 m^3/h. The improvement is capable to lower the average value of PMV to +1.63 and average PPD 58.58%. It can be conclude that the thermal comfort improvement should be focused just only on six factors of PMV formulation.