The Dilemma between Reducing the Thermal Stress in the Industrial Spaces and Ergonomics Arrangement in Low- and Middle-income Countries

Abstract

Thermal heat stress is a leading cause of numerous occupational diseases that disturb worker performance and work quality and, in extreme circumstances, can result in death. When employees are exposed to severely hot or cold thermal settings, thermal discomfort is listed as one of the leading reasons for discontent in the job. Given the time individuals spend at work, studies assessing the comfort of the thermal environment are becoming increasingly relevant. However, most industrial spaces in low- and middle-income countries are designed without considering the workers' thermal comfort, which leads to an unmeasured decrease in productivity and many health considerations. This research aims to provide a methodology for developing the indoor thermal comfort of the workers in industrial spaces by optimizing the workers’ ergonomics, activity profiles, and building shell without implementing any mechanical cooling systems, which is not usual in low- and middle-income areas. The methodology is based on building a computer-based model on the Design Builder simulation tool based on current measures of temperature, humidity, wet-bulb temperature, air speed over each window, and indoor surface temperatures. Then, three different scenarios were built to optimize the indoor ergonomics of the factory in the first scenario, and the building shell in the second scenario, the activity profiles of the workers in the third scenario to become correspond with the NOISH criteria of maximum metabolic rate for each WBGT. After that, each scenario's results were associated with the workers' thermal sensation and air temperatures, which correlated the ergonomics of industrial spaces and the thermal comfort of workers there. The results of each scenario simulation were represented by horizontal and vertical sections of the air temperature and Percentage of People's Discomfort (PPD). Each scenario’s results referred to a decrease in the air temperature and PPD; however, all the scenarios combined decreased the PPD to around 50% for most of the measured working stations. The research concluded a methodology of optimizing any industrial space thermal performance without implementing any active ventilation techniques, which is considered the usual form of any industrial space in Egypt and most low and middle-income countries. Therefore, the presented methodology applies to most industrial spaces that face the dilemma of decreased productivity due to indoor thermal heat loads that affect the workers.