• Journal of the Korean Solar Energy Society
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• v.27 no.1
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• pp.63-74
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• 2007

Together with the concern about the indoor all quality as sick house syndrome, the Ministry of Environment announced "Indoor Air Quality Control Law for the Multi Purpose Facility," which made the interests to be focused in the urgent understanding of current condition and preparation of measures about the indoor air pollution. In Dec 2005, the law was revised to obligatorily notify the amount of Formaldehyde and Volatile Organic Compounds in the case of newly constructed apartments with more than 100 houses. School also have its own indoor air quality guideline, Indoor air quality in school is very important because, children who very weak to indoor pollutants reside long time in there. The purpose of this paper is to survey indoor air qualify in school by field measurement. Field measurements were performed in 11 schools which were selected from 3 major cities(Incheon, Dae-jeon, chuncheon) in korea, during July, 2004. Totally concentration of Indoor pollutants were determined in 27 classroom. Target air pollutants were TVOC, formaldehyde, dust, CO, CO2 and NO2. For the result of this investigation, Indoor air quality in classroom was very poor and it was found that some pollutants (TVOC, float bacteria) exceed the guideline.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.11
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• pp.1043-1049
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• 2005

The purpose of this study is to improve indoor air quality of the barracks which have been changed from floor-type living barracks to bed-type living barracks since 2003. Therefore, the ventilation rates of newly constructed two type barracks were simulated with the various building materials including VOCs and HCHO components. And indoor air quality of two type living barracks was measured by the field experiments. With these steps, the measures for upgrading indoor air quality depending on building material types and ventilation rate are suggested.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.27 no.6
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• pp.541-547
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• 1998

공기 중에 존재하는 미생물(바이오에어로졸, bio-aerosol)은 많은 질병 발생의 원인이다. 의학계에서는 바이오에어로졸과 공기 매개성 질병의 전파와의 연관성이 잘 알려져 있다. 특히 결핵, 수두, 홍역, 천연두의 발병은 공기를 통한 질병 전파의 중요성을 확인시켜 준다. 그러나 IAQ(indoor air qualify)의 영향은 최근에서야 조사되었다. 보건의료기관과 연구실험실에서는 세균과 진균의 감염이 HVAC 시스템을 통해서 종종 일어난다. 유사한 IAQ연구에서는 바이오에어로졸이 빌딩증후군과 같은 빌딩과 관련된 질병(building-related illness, BRI), 감염, 중독성 증상, 민감성 질병과 1차적으로 연결되어 있음을 발견되었다.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.140-148
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• 2006

Recently, indoor air quality (IAQ) in workplace, residential environments and schools has been concerned of people, scientists and related the public, and has recognized the health effects related to indoor air pollution. Therefore, this study was performed to investigate the characteristics of IAQ in 55 kindergartens, elementary school, middle schools, and high schools from June, 2004 to May, 2005 in Korea. We measured indoor air pollutants($PM_{10},\;CO_2$, HCHO, total bacteria colony(TBC), CO, radon, TVOCs, asbestos, and $O_3$), and physical factors(noise, temperature, relative humidity, and illumination) with necessary of management for IAQ in school. We classified into 5 kinds of the school by period since building completion, <1 year, 1-3 years, 3-5 years, and 5-10 years. The concentration of pollutants and the level of physical factors compared with standards and guidelines of IAQ on the Ministry of Environment, the Ministry of Health and Welfare, and the Ministry of Education and Human Resources Development. The major results obtained from this study were as follows. Temperature, relative humidity and illumination among the physical factors did not exceed the standards, but noise exceeded it. Asbestos and $O_3$ did not detect in surveyed classrooms. CO, TBC, TVOCs, and HCHO in kindergartens, TBC in elementary schools, TBC, TVOCs dnd HCHO in middle schools, and HCHO in high schools detected the standards. This study is conducted as a part of efforts to provide a foundational data for further relative researches on management of IAQ of school. Therefore, we suggest that country plan for management of IAQ in school should be established through long-term and continuous investigation for assessment on IAQ in school and health risk assessment for students.

• Journal of Energy Engineering
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• v.11 no.2
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• pp.130-135
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• 2002

Bypass air conditioning systems are divided into three types; outdoor air bypass, mixed air bypass and return air bypass system. Among bypass air conditioning systems, a return air bypass system is more effective than other two systems because it doesn't induce unconditioned outdoor air into conditioned room. The numerical study on the bypass air conditioning system shows this system can maintain indoor RH(Relative Humidity) less than a conventional CAV (Constant Air Volume) air conditioning system by adjusting face and bypass dampers at part load. A simulator was built to compare results of a numerical experiment and those of a simulator experiment. The results of the simulator experiment was nearly same as those of the numerical experiment; when a design sensible load (the ratio of sensible load to total sensible load) was 70 percent (at this time, RSHF=0.7), indoor relative humidity (in case of both numerical experiments and simulator experiments) was maintained below 60% specified by ASHRAE STANDARD 62-1999. The bypass air conditioning system is expected to be applied to many buildings where the Percentage of latent loads or air change tate is high.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.482-489
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• 2004

The purpose of this study is to reevaluate the performance of Hanji as a architectural material. Recent studies report that one of the causes of the Sick-HouseㆍSick-Building Syndrome is due to the contaminants from interior materials and the lack of ventilation. In this study, the properties of Hanji are investigated. The major focuses of this research are (1) how efficient the Hanji is for ventilation of the house and (2) whether the usage of Hanji brings required ventilation volume to the house. According to the test results, differential pressure in the air and the amount of ventilation showed linear relationship. Test results differ from various kinds of Hanji. Since houses usually have double window system, Hanji can be used to the windows system, especially for inner part of double window system. It is suggested that the combination of Hanji windows for the inner part and glass windows for outer part is very effective, and offers a solution to improvement of indoor air quality and the lack of ventilation with passive ventilation that has less energy consumption.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.628-634
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• 2005

We have simulated and proposed novel optical cavity, which has two elliptical mirrors, for NDIR gas sensor module and have tested it from 0 ppm to 2,000 ppm $CO_2$ concentration. The proposed sensor module shows the maximum peak voltage at 500 ms pulse modulation time, however, it shows a maximum voltage changes at 200 ms pulse duration with 18,000 times amplification gain. From 0 ppm to 2,000 ppm, the voltage difference of sensor module $({\Delta}V)$ shows 360 mV at 200 ms pulse duration and 3 sec turn-off time. The response time of designed sensor module is about 30 seconds.

• Journal of environmental and Sanitary engineering
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• v.20 no.3 s.57
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• pp.1-9
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• 2005

Recently, indoor air quality (IAQ) in workplace, residential environments and schools has been concerned of people, scientists and related the public, and has recognized the healthy effectsrelated to IAQ, specially in schools in Korea. Therefore, objectives of this study in this study were to measure and compare the perception of TAQ of selected air pollutants in Seoul from April to September 2004. Measurement place measured 2 schools of Seoul and local 9 schools (by Kyonggi Province, Chungchong-bukdo Chungchong-namdo, Chollado-bukdo, Cholla-namdo, Kyongsang-bukdo, Kyongsang-namdo, Kwangju, schoolin Pusan each 1 place). Temperature, humidity, illumination, carbon monoxide, carbon dioxide, TBC (total bacteria count), noise, PM10, TVOC(total volatile organic compounds), HCHO (formaldehyde) were measured simultaneously. Also, we Performed a questionnaire survey of 250 students and 50 teachers about their awareness for the importance of IAQ in their schools. Among this article, we handled noise, carbon monoxide, carbon dioxide, TBC, TVOC, HCHO, PM 10 in our conclusion. Major results were as follows ; Carbon monoxide (CO) was lower than indoor air standard of Korea. Carbon dioxide $(CO_2)$ appeared that 4 schools among our sample target school exceeded in normal standard. 4 schools were almost similar with normal standard. TBC appeared that 7 schools among 11 schools were higher than standard. Noise measured school's mean value passed exceeded standard. And school which passed over standard appeared to 7 schools among 11 schools. HCHO was exceeded 4 schools by standard that excess and certainly interrelation between school's establishment year and facilities of construction was detected. PM10 was exposed all schools by fitness in standard. TVOC appeared that 9 schools among 11 measurement school was exceeded health effect standard of Japan.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.421-426
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• 2005

For the air-conditioner, refrigerant induced noise and vibration should be the problem when it reduced airflow rate in order to reduce the noise at low mode. With the test, it could be verified that one of the main reason for refrigerant induced noise were the velocity and flowing induced force of the refrigerant at the inlet of evaporator. So in order to reduce this velocity with same mass flow rate of refrigerant, quality at the evaporator inlet should be minimized. And in order to reduce flowing induced force of the refrigerant, flowing direction change should be eliminated. So in this paper, it would like to review the characteristics of refrigerating cycle at first and find how the quality and flowing induced force can be minimized.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.243-252
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• 2005

Purpose: Indoor air quality (IAQ) in the radiation treatment center which is generally located underground is important to the health of hospital workers and patients treated over a long period of time. this study was conducted to measure and analyze the factors related to IAQ and subjective symptoms of sick building syndrome, and to establish the causes influencing IAQ and find a solution to the problems. Methods and Materials : Self administrated questionnaire was conducted to check the workers' symptoms and understanding of the work environment. Based on a preliminary investigation, the factors related to IAQ such as temperature, humidity, fine particulate. carbon dioxide, carbon monoxide, formaldehyde, total volatile organic compounds (TVOC), and radon gas were selected and measured for a certain period of time in specific sites where hospital workers stay long in a day. And we also evaluated the surrounding environment and the efficiency of the ventilating system simultaneously, and measured the same factors at the first floor (outdoor) to compare with outdoor all quality, All collected data were assessed by the recommended standard for IAQ of the domestic and international environmental organizations. Results: Hospital workers were discontented with foul odors, humidity and particulate. They complained symptoms related to musculo-skeletal system, neurologic system, and mucosal-irritatation. Most of the factors were not greater than the recommended standard, but the level of TVOC was third or fourth times as much as the measuring level of some offices in the United States. The frequency and the amount of the ventilating system were adequate, however, the problem arising in the position of outdoor-air inlets and indoor-air outlets involved a risk of the indraft of contaminated air. A careful attention was a requirement in handling and keeping chemical substances including a developing solution which has a risk of TVOC emissions, and repositioning the ventilating system was needed to solve the contaminated-air circulation immediately Conclusion We verified that some IAQ-related factors and inadequate ventilating system could cause subjective symptoms in hospital workers. The evaluation of IAQ was surely needed to improve the underground working environments for hospital workers and patients. On the basis of these data, from now on, we should actively engage in designs of the department of radiation oncology or improvement in environments of the existing facilities.