• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1220-1224
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• 2008

Because of the high airtightness and insulation of the building, indoor environment has been largely polluted resulted from insufficient ventilation and occurrence of new air pollutant. These factors have made worse indoor air quality and caused symptoms of the SHS(Sick House Syndrome), MCS(Multi Chemical Sensitivity). The purpose of this study is to present the fundamental strategies for improving the Indoor Air Quality(IAQ) in newly-constructed apartment buildings. To investigate the concentration of indoor air pollutants such as Formaldehyde and VOCs, the field measurement were conducted.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.277-282
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• 2006

In order to predict the indoor air pollutant, the VOCs emission rate is used through small chamber in the design process. However, the small chamber method has limitations as the convective mass transfer coefficient, the most important factor when predicting VOCs contamination of indoor air, is different between the small chamber result and the measured data in the actual building. Furthermore, the existing studies which analyzed mass transfer coefficient in the small chamber were directed on the small chambers developed at the time and FLEC(Field and Laboratory Emission Cell), thus, are different from the current small chamber which has been changed with improvements. The purpose of this study is to determine the emission rate of pollutant in double-layered building materials through the CFD(Computational of Fluid Dynamics) and Numerical analysis based on the mass transfer coefficient on singled-layered building material by using the current small chamber widely used in Korea. Futhermore, this study used the new convective mass transfer coefficient($h_m'$) which indicates the existing convective mass transfer coefficient($h_m$) including VOC partition coefficient(k). Also, formaldehyde was selected as target pollutant.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.134-144
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• 1998

A comprehensive air quality monitoring was carried out to investigate the criteria concentration of air pollutant in indoor of subway stations of Seoul City. The samples were collected twice per year (the first and the second half of the year) at each sampling point from February to September in 1997. Sampling point of subway stations was ticket office and platform. The measurement of indoor air pollutants such as sulfur dioxide(SO$_2$), nitrogen dioxide(NO$_2$), carbon monoxide(CO), carbon dioxide(CO$_2$), total suspended particulate(TSP) was performed to determine the indoor air quality. Heavy metals(Pb, Cd, Cu, Cr, As, Hg) were also measured together with those air pollutants. The annual average concentration of CO$_2$ and TSP in subway stations were relatively high while those of heavy metals were within 10% of environmental recommended standard concentration in all stations. As results of regression analysis between line and line of air factors, the concentrations of CO, CO$_2$, TSP, Pb, Cd, Cr and Cu were highly correlated, but those of $SO_2, NO_2$ and Hg were not correlated. As results of regression analysis between ticket office and platform, the concentrations of heavy metals such as Cr and Cu were highly correlated. Results of oneway analysis of variance between the first and the second half of the year air factors also indicated that CO, CO$_2$, Cd, Cu, Hg were significant($\alpha$=0.01), respectively. The average contration of total suspended particulate(TSP) in subway line No. 1 was shown high concentration(200 $\mu g/m^3\cdot$ day) level.

• Asian Journal of Atmospheric Environment
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• v.12 no.3
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• pp.204-214
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• 2018

Indoor air quality was investigated in homes and daycares located in areas with heavy traffic in Seoul, South Korea from November 2013 to January 2014. Indoor and outdoor air quality measurements were collected for 48 hours in four children's homes and daycare centers. The I/O ratio (Indoor to outdoor ratio) for each major air pollutant ($NO_2$, black carbon, $PM_{10}$, and $PM_{2.5}$) was calculated, and $NO_2$ and $PM_{10}$ concentration profiles were analyzed based on indoor activity diaries recorded during the 48 hours. Most I/O ratios for $NO_2$, black carbon, $PM_{10}$, and $PM_{2.5}$ at daycare centers were less than one. At homes, I/O ratios for black carbon, $PM_{10}$, and $PM_{2.5}$ were less than one; however, most I/O ratios for $NO_2$ were greater than one due to the usage of gas stoves. The children's exposure to indoor air pollutants was calculated using a time-weighted average exposure method, and the daily intake level for each pollutant was determined.

• Journal of the Korean housing association
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• v.19 no.1
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• pp.49-55
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• 2008

Recently, much attention has been paid to the problem such as sick building syndrome, which caused by the indoor air pollutant. Volatile Organic Compounds $(VOC_s)$ and formaldehyde have been considered as one of the main reason that causes indoor air pollutant. This study is for introducing and designing thermal performance of super energy saving building by conducting $VOC_s$ and formaldehyde concentration in the 3Liter house. The results of the measurement for 10 months showed that $VOC_s$ and formaldehyde decreased until the guideline concentration. It took about 7 months, and it appeared right after new construction. However, their levels were showed higher concentration in comparison with the ordinary residential houses (apartment house). The main difference of between newly built 3Liter house and ordinary apartment is their air changes, which are 0.67/h for 3Liter house and 4.0/h for the apartment.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.5
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• pp.187-194
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• 2020

This study presents the energy-saving sequential control algorithm to handle indoor CO₂ and PM2.5 for the improvement of the air quality of school classrooms. To solve indoor air quality (IAQ) problems, air cleaning and ventilation systems are mainly used for school classrooms. Although air cleaning is able to collect PM2.5, it is difficult to remove harmful gas substances. The ventilation system is suitable to tackle CO and CO₂, the volume ventilation, however, is relatively small. In this paper, to remove CO₂ and PM2.5, the pollutant balance equation for improving indoor air quality is reviewed. The sequential control algorithm of the ventilation and air cleaning system with four levels of criteria is introduced for the effective removal of pollutants. The proposed sequential control algorithm confirms that indoor CO₂ and PM2.5 can be properly controlled below the standard value. In addition, the sequential operation of air cleaning and ventilation systems has shown significant improvement in IAQ compared to the independent ventilation system operation. Particularly, such systems are efficient when outdoor PM2.5 is high.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.222-228
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• 2013

Objectives: The indoor air quality of newly-built (NC) and remodeled (RC) school classrooms was assessed. The primary aim was to show correlations between volatile organic compounds (VOCs) and formaldehyde (HCHO) pollutant levels. Methods: This study investigated the indoor air concentrations of VOCs and HCHO at 26 sites of newly built and 68 sites of remodeled classrooms located in South Gyeongsang Province between 2010 and 2012. VOCs in the indoor air were determined by adsorbent tube (Tenax TA) and automatic thermal desorption coupled with GC-MS analysis. Target analytes were five VOCs: benzene, toluene, ethylbenzene, xylene, and styrene. HCHO was collected with a 2,4-DNPH cartridge and analyzed by HPLC. Conclusions: This study estimated that indoor VOCs and HCHO concentrations in the classrooms were mainly affected by interior building materials and classroom equipment. For proper indoor air quality in schools, classroom air should be improved through reduction of hazardous materials by adequate ventilation, selecting environmental friendly materials, etc.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.47-57
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• 2013

Studies evaluating the health effects of hazardous air pollutants assume that people's exposure to typical pollutant level is the same as specific regional pollutant level. However, depending on social and demographic factors, time-activity pattern of people can vary widely. Since most people live in indoor environments over 88% of the day, evaluating exposure to hazardous air pollutants is hard to characterize. Objective of this study was to estimate the exposure levels of university students of $NO_2$, VOCs(BTEX) and $PM_{10}$ using the scenarios with time-activity pattern and indoor concentrations. Using data from time-use survey of National Statistical Office in 2009, we investigated time-activity pattern of university students and hourly major action. A total of 1,057 university students on weekday and 640 on weekend spent their times at indoor house 13.04 hr(54.32%), other indoors 7.70 hr(32.06%), and transportation 2.36 hr(9.83%). Indoor environments in which university students spent their times were mainly house and school. Air pollutants concentrations of other indoor environments except house and school such as bar, internet cafe and billiard hall were higher than outdoors, indicating that indoor to outdoor ratios were above 1. According to three types of exposure scenarios, exposure to air pollutants could be reduced by going home after school.

• Land and Housing Review
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• v.14 no.4
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• pp.103-110
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• 2023

People who spend most of their day indoors are continuously exposed to internally and externally generated indoor pollutants. According to a 2022 report from the World Health Organization (WHO), air pollution is the cause of more than 7 million deaths annually worldwide, emphasizing the seriousness of indoor air pollutants. Air pollutants include nitrogen oxides (NOx), formaldehyde (HCHO), and volatile organic compounds (VOCs), which have serious effects on the human body. Photocatalyst is a material that can remove these indoor air pollutants. Photocatalysts not only have the ability to remove dust precursors, but also have antibacterial, sterilizing, and deodorizing functions, making them effective in improving indoor air quality. This study suggests areas and methods in which photocatalysts can be applied to buildings. Fields of application include interior and exterior construction materials such as concrete, as well as organic paints and ventilation devices. If appropriate utilization plans are developed, it may be possible to improve the built environment through reduced indoor and outdoor pollutant levels.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.13-19
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• 2021

In modern society, indoor activities time is increasing due to industrial development. Interest in indoor air quality is increasing as indoor activity time increases. The main causes of indoor air pollution are formaldehyde which a chemical cause, and fungi which a biological cause. Phytoncide effectively reduces Formaldehyde and Fungi. Charcoal which possess porous-structure has a good absorbance of pollutants. In this study, the authors manufactured functional cement matrix using by phytoncide and charcoal to remove formaldehyde and fungi. In this study, Functional cement matrix reduced formaldehyde and Fungi and effectively improve indoor air quality.