전자산업 생산현장 PMV 개선 및 생산성 향상에 관한 연구

Abstract

Modern people have been interested in comfort indoor environment, as the standard of living has been improved according to social and cultural development. Especially, air quality cause modern people who usually stay in indoor places to get disease like Sick Building Syndrome, moreover it has influenced workers' health, comfort requirements and operation efficiency in the production sites of electronic industry. Usually, modern people have been lived in confined buildings, so that we can not helping being subject to artificial indoor environment. Under indoor environment without self-purification, air conditioners, air handling units and air purifiers can make comfort environment. In here, the requirements for comfort environment are thermal environment which related to temperature and humidity, air quality environment which are influenced by hazardous gas and dust, acoustic environment, light environment, and etc. The ventilation methods of indoor space can be divided into natural ventilation and mechanical ventilation. Since enough ventilation can not be occurred by only natural ventilation which makes use of the natural flow of air by temperature variations between outdoor and indoor, or the wind power of open air, generally we use mechanical ventilation methods for indoor ventilation. To control indoor thermal environment, nowadays, thermostat and humidist which are controlled by temperature and humidity are using. However it is necessary to consider and control all the factors such as humidity, wind speed, radiation, etc, also including temperature, since those factors are complexly involved in indoor thermal environment. So to speck, we adopted this research to find out the method of productivity improvement in production sites, as we planned to set up control factors for indoor thermal environment using more complex Thermal Environment Index and to control indoor thermal environment as similar to warmth and cold that people usually felt. The purpose of this study is to make comfort environment ideal to improve productivity, as we inquire into the control condition and the phenomena of thermal environment and air quality in the production sites of 'S' Electronics, and also suggest alternative plans for improvement by measuring the workers' satisfaction with indoor air quality. The summary of this study is that firstly we measured thermal environment and air quality from 3 production sites in 'S' Electronics. The result that we analyzed the problems is that PMV(Predicted Mean Vote) was recorded as 0.20, which was definitely required to be improved, according to the cooling load of refrigerators production sites. On the other hand, the PMV of the air conditioners and washing machines production sites was from -0.17 to -0.07, and it means their thermal environment was quite excellent. However, in air conditioners production site, it was necessary to improve the function of ventilation, since the position and the operation of some ventilations were poor in the process of welding, so the density of CO2 was too high. Then, through the questionnaire survey of workers, it was found that workers in refrigerators and washing machines production sites were the most highly dissatisfied with air quality, as they were recorded like 52% and 55%. This fact caused workers to have respiratory diseases, and workers with respiratory diseases were 68% in refrigerators site, more than 36% in washing machines and air conditioners sites. We analyzed the relative frequency of PMV and production improvement that were compared with the characters of work. As a result, we found that there was the productivity loss of 2% in air conditioners site, 3% in washing machines site, and 8% in refrigerators site. The result of this study were as follow: 1) The improvement of thermal environment in production sites 2) The improvement of air quality 3) The improvement of dissatisfied factors by questionnaire survey, etc It should be focused to maintain production environment that make workers feel comfort. In fact, we had planned to suggest improvement programs for proper thermal environment and air quality in the production sites of electronic industry, however it is difficult to say that the contents suggested by this study completely corresponds with the improvement of thermal environment in the whole production sites of electronic industry. Simply, we should keep trying to control and maintain indoor thermal environment as similar to body heat, to create ideal indoor thermal environment for workers to suggest improvement plans which fit in each character of control and thermal environment depending on production sites. Accordingly, we would like to indicate the PMV improvement plans of production sites through workers' interview and basic surveys for PMV improvement in production sites, and to make a contribution to improve the production environment which is related to PMV in other production sites by measuring the relation of productivity and the result of improvement