• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.300-310
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• 2012

Objectives: Indoor air quality problems in public spaces have recently become a very important issue in South Korea, because many spend a long time every day indoors. In this study, an extensive literature review was performed on the subject of suspended bacteria and fungi in public facilities. The objective of this study was to evaluate the extent and types of suspended bacteria and fungi in indoor air in South Korea. This study will provide direction to the research in the field of indoor air. Methods: Article reviews was conducted using a search engine and the following keywords; 'bacteria', 'total suspended bacteria', 'fungi' and 'indoor air' from published articles since 2000. Results: Most of the places of measurement were schools, kindergartens, childcare centers and general hospitals. The highest concentrations of total suspended bacteria and fungi were found in schools and kindergartens. Some public facilities exceeded the standard of 800 CFU/$m^3$. There were few studies on other suspended bacteria: Gram Negative Bacteria, Staphylococcus and Klebsiella pneumoniae. Conclusions: It appears that more studies with intensive controls are needed. It was found that schools and kindergartens were most susceptible to microbial indoor air pollution. These results may be able to suggest an indoor standard for suspended bacteria and fungi in South Korea.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.217-223
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• 2019

The purpose of this study was to measure the indoor air quality of small-scale apartments and then proposed a method to improve the indoor air quality of the small-scale apartments by comparing with the result of indoor air quality in the Clean-Healthy House. In case of formaldehyde, a highly volatile organic compound, the concentrations of indoor measured both in small-scale apartments and the Clean Healthy houses did not exceed- the guideline of Korea. The guideline of Korea for acetaldehyde was not available, so the guidelines of Japan and the World Health Organization were used to measure the concentration of acetaldehyde. The study results demonstrated that three out of seven small-scale apartments investigated exceeded the guideline of Japan; and the preliminary research on the Clean-Health Houses was low at about 30-60% of the guideline of Japan. The result of the VOCs measurement showed that toluene, ethylbenzene, and styrene in some small-scale apartments exceeded the guideline of Korea. However, the Clean-Healthy Houses in the previous studies did not exceed the guideline of Korea with regard to all the pollutants. Therefore, this study suggests the application of the construction standards of the Clean-Healthy house in order to improve the indoor air quality of small-scale apartments. In addition, the current study anticipates that improvement of the indoor air quality in the residential environments should be universally applied, not limited to the type and size of the residence.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.87-94
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• 2017

Objectives: This study was conducted to determine the impact of aquariums on indoor air quality for improving humidity and reducing indoor air pollutants. Methods: An air-conditioning chamber was used to determine humidity increase by aquarium volume at three different temperatures ($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$). Humidity increase was measured for 21 hours ($20^{\circ}C$) and 12 hours ($25^{\circ}C$, $30^{\circ}C$) while placing five different volume of aquarium in the chamber. Concentrations of several volatile organic compounds and formaldehyde were measured after a known amount was injected into the chamber with and without an aquarium. Results: The humidity inside the chamber increased when the aquarium was inside the chamber. Humidity change was similar at $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$, but slightly higher at higher temperatures. The bigger the aquarium volume, the higher was the humidity increase that occurred. Humidity increase by the aquarium was sufficient to increase indoor humidity in winter and negligible in summer. Concentrations of some water-soluble indoor air pollutants and formaldehyde were decreased with the aquarium inside the chamber. Conclusions: An aquarium could increase indoor humidity in winter, while the humidity increase is negligible in summer. An aquarium could decrease some water-soluble indoor air pollutants, including formaldehyde. This result implies that an aquarium may have positive effects on indoor environmental quality.

• Journal of the Korean Society of Visualization
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• v.20 no.2
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• pp.21-27
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• 2022

Air purifiers can be placed where the air cleaning is required, making it easy to manage indoor air quality. The position of the air purifier affects the indoor airflow pattern, resulting in different air cleaning efficiency. Many efforts and strategies have been examined through numerical simulations and experiments to find the proper location of the air purifier, but problems still remain due to the various geometrical indoor spaces and arrangements. Herein, we develop an artificial intelligence model to predict the performance of an air purifier depending on the installation location. To obtain the training data, numerical simulations were performed on the different locations of the air purifiers and airflow patterns. The trained artificial intelligence model predicted the air exchange performance depending on the installation location of the air purifier with a prediction accuracy of 92%.

• KIEAE Journal
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• v.9 no.2
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• pp.59-64
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• 2009

The senior citizens population and welfare institution for them is increased. The senior citizens in welfare institution spend a long time in indoor and their health is greatly affected by the indoor environment. Therefore, the indoor environment of senior citizens welfare institution is very important. This study presents some primary data based on the survey of architectural conditions and the measurements of indoor air quality for senior citizens welfare institution. According to characteristic of region, six of Incheon Area's senior citizens public welfare institution are selected. An investigation and analysis into architectural conditions and indoor air quality including temperature, humidity, CO, $CO_2$, PM10, HCHO, TVOC are conducted. The temperature, humidity and $CO_2$ concentration is some high. The HCHO concentration is very high. The indoor flooring and furniture materials highly impacts on the concentration of HCHO and TVOC.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.3
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• pp.240-246
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• 2002

Bypass air conditioning systems are divided into three types; an outdoor air bypass, a mixed air bypass and a return air bypass system. What makes the return air by pass system more effective is that it directs all of moist outdoor air through the cooling coil. The bypass air conditioning system can maintain indoor R.H (Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. When a design sensible load (the ratio of sensible load to total sensible load) is 70 percent (at this time, RSHF (Room Sensible Heat Factor) . 0.7), indoor R.H was maintained 59 percent by the return air bypass system, but 65 percent by the conventional CAV air conditioning system (valve control system). The bypass air conditioning system can also improve IAQ (Indoor Air Quality) in many buildings where the number of air change is high.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.263-270
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• 2010

In this study, an air cleaner is considered to improve comfort, safety, and health of automobile passengers. The performance and installation conditions of the air cleaner have been studied to investigate their effects on the air quality in the cabin room using numerical analysis. A five-passenger sedan and a seven-passenger minivan that have comparatively large indoor volume have been considered. The distributions of the local mean age and the volume averaged age of indoor air are calculated according to the variation of the placement and the air flow of the air cleaner. In addition, a decrease of contamination concentration, especially VOCs(volatile organic compounds), by the air cleaner is numerically analyzed with time-accurate unsteady calculation to quantify the effect of the air cleaner on the indoor air quality. As a result, the effective installation and operation conditions of the air cleaner for the automobile cabin room could be suggested.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.241-249
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• 2001

A report by the National Research Council in the United States suggested that many lung cancer deaths each year are associated with breathing radon in indoor air. Most of the indoor radon comes directly from soil beneath the basement of foundation. Recently, radon released from groundwater is found to contribute to the total inhalation risk from indoor air. This study presents the assessment of a exposure to radon released from the groundwater into indoor air. At first, a 3-compartment model is describe the transfer and distribution if radon released from groundwater in a house through showering, washing clothes, and flushing toilets. The model is used to estimate a daily human exposure through inhalation of such radon for adults based on two sets of exposure scenarios, Finally, a sensitivity analysis is used to identify important parameters. The results obtained from the study would help to increase the understanding of risk assessment issues associated with the indoor radon released from groundwater.

• Analytical Science and Technology
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• v.20 no.1
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• pp.17-24
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• 2007

This study was performed to investigate the distributions of volatile organic compounds and carbonyl compounds at the 120 households in new apartments before occupation. The concentration of toluene, m, p-xylene, formaldehyde, acetone and ethylbenzene dominated as $272.81{\mu}g/m^3$, $98.90{\mu}g/m^3$, $71.68{\mu}g/m^3$, $70.58{\mu}g/m^3$ and $49.76{\mu}g/m^3$, respectively. The identified compounds by standards occupied 42.5% of the TVOCs, also the concentration of toluene occupied the largest part of the identified compounds as 18.5%. The concentration of formaldehyde and acetone were 43.1% and 42.4% among carbonyl compounds. The indoor/outdoor ratio of the concentration of benzene, toluene, formaldehyde and o-xylene were investigated 1.29, 3.59, 10.76 and 28.74, respectively.

• Analytical Science and Technology
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• v.20 no.6
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• pp.474-482
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• 2007

Daycare centers are an important indoor environment for pre-school children and exposure area with potential harmful health effects for infants and children who spend most of their daily life. Sampling was undertaken at 29 daycare centers located Seoul in Korea from January, 2006 to December 2006. The target compounds were 7 individual volatile organic compounds (benzene, toluene, ethylbenzene, m,p-xylene, styrene, o-xylene, TVOC). The mean concentrations of TVOC, toluene, m ,p-xylene, ethylbenzene, benzene and styrene in daycare centers were $318.7{\mu}g/m^3$, $51.6{\mu}g/m^3$, $11.7{\mu}g/m^3$, $6.5{\mu}g/m^3$, $4.2{\mu}g/m^3$, $3.6{\mu}g/m^3$, respectively. Toluene occupied 17.6 % of the concentration of individual VOCs. The ratio of indoor and outdoor (I/O) of TVOC and toluene were 2.0 and 1.6, respectively. The results of characteristics according to a season of a year, the concentration of TVOC were measured $433.9{\mu}g/m^3$, and these concentrations during third quarter of the year in summer were higher than the other season. In the other four seasons, TVOC were measured 280.5 in winter, 298.3 in spring and $264.6{\mu}g/m^3$ in fall, respectively.