• 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.

• Prospectives of Industrial Chemistry
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• v.23 no.4
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• pp.1-12
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• 2020

최근 실내 공기질(IAQ; indoor air quality)을 악화시키는 물질 중 하나인 이산화탄소 저감 연구가 다수 진행되고 있다. 현재 이산화탄소를 저감하는 방법에는 흡착법, 흡수법, 막분리법 등이 있다. 그 중 흡수법은 액체 상태의 흡수제를 분사하는 공정 특성상 실내에 적용하기 어렵고 2차 오염물 또는 폐수가 발생할 수 있다. 또한, 막분리법은 이산화탄소 분리를 위한 응집 및 침전과 같은 전처리 과정이 필요하므로 실내 이산화탄소 저감에 적합하지 않다. 반면, 흡착법은 비교적 저렴하고 운영이 간단하여 적용 사례가 증가하였으며, 유동 인구가 많고 환기가 어려운 지하철, 버스 등의 대중교통 차량 내부 및 교실, 사무실, 공공시설에서 배출되는 실내 이산화탄소를 제어할 수 있다는 장점이 있어 가장 적합한 해결책으로 알려져 있다. 흡착 공정에 사용되는 대표적인 흡착제 종류에는 활성탄, 제올라이트, 알루미나 등이 있으며, 이 흡착제들을 개질 및 성형하여 흡착제의 성능 및 기계적 강도를 증진시키는 고도화 연구가 활발히 수행되고 있다. 이처럼 적용 대상 내 설치 및 교체가 용이하도록 하는 흡착제 제조 기술 개발이 필요한 실정이며, 흡착제를 상용화 수준까지 발전시킴으로써 강화된 실내 공기질 규제 기준에 대한 대응 및 삶의 질 향상이 기대된다.

• KIEAE Journal
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• v.7 no.5
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• pp.93-98
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• 2007

Effort has been performed for latest 20 years to improve resident's comfort and indoor environment in building. And interest and effort to improve indoor air environment among various indoor environment elements have continuously increased since 1990s, because it is examined scientifically that various contaminants generated indoor affect human body. Specially, indoor air contaminants generated from apartments are those exhausted from resident's indoor environment, closing materials and household. Indoor air environment in buildings is different according to pollution degree, existence availability of pollution source, ventilation amount, and meteorology. It is known that other contaminants more than about 900 kinds generate according to a kind of work or action in a room. Specially, nowadays buildings are well insulated and confidentiality-centered for environment protection and economical side. So indoor air contaminants are generated from indoor air pollution sauces of unprepared ventilation, human body carbon dioxide emissions, and various building materials. when these are accumulated in long term human body, it is harmful to resident's health, but awareness for this is very insufficient. Because bedroom is space that people inhabit for a long time by unconscious state and indoor environment occupies important part for resident's health and quality of life at sleep, the actual condition of air quality is investigated, improvement countermeasure is considered, and ventilation amount is analyzed. In this study, putting case that the most longest stayed time is sleeping time when people inhabit in the apartment, the air quality according to volume of bedroom space at sleep was measured and analyzed, and the data acquired will be the basis for improvement on this.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.377-381
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• 2006

The purpose of this study was to suggest the improvement plan for IAQ of the combined officetel and residence through analyzing demands, satisfaction, subjective symptoms and device of residents. For this study, the data was collected from 110 residents by questionnaire survey and an experienced planner by interview. The result showed that the IAQ improvement of the combined officetel and residence was urgent. The educational program about maintenance of IAQ for residents was essentially needed. To recommend eco-friendly materials in process of construction wasimportant so as to take precaution against ‘sick building syndrome'. It was also necessary to improve on the size and shape of ventilation window.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.123-129
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• 2007

The purpose of this study was to suggest the idea for IAQ improvement of the of officetel which is used by fully or partly residential space. The data was collected from 110 residents by questionnaire survey and an experienced architect by personal interview. The results showed that the IAQ improvement of the officetel with residential usage and residence was urgent. The educational program about maintenance of IAQ for residents was essentially needed. To recommend eco-friendly materials in process of construction was important so as to take precaution against 'sick building syndrome'. It was also necessary to improve on the size, shape, and location of ventilation window.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.119-125
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• 2002

The concept of dwelling space is tend to be changed not only to have reasonable mobility but also to have high quality of indoor air with psychologicaa satisfaction and comfortable. Moreover, recent constructed buildings have a big problem because of exhausted pollution gas and particles from building materials. More serious problem occurs from its high air tightness reducing the ventilation for saving the energy and superior adiabatic insulators to have high heat efficiency. Indoor air quality in super high-rise dwelling house was investigated by measuring pollutants such as $CO_2,=;CO,\;MO_2,\;R_n,\;TSP,\;PM_{10}$, HCHO, Offensive ordor. Subjective evaluation of residential environment is processed for the inhabitants who live in research space by testing environmental load in accordance with environment morphology, exterior environmental factor and post occupancy correlation and influence of attention.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• Journal of Environmental Policy
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• v.7 no.2
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• pp.67-90
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• 2008

The purpose of this study is to develop indoor air quality management strategies regarding indoor air pollutants while considering various factors affecting indoor pollutants concentration. The Integrated Indoor Air Quality model(IIAQ) developed by Seoul National University is used for this study. The IIAQ model is a tool that can provide an integrated view to indoor environmental pollution by simulating suggested scenarios. The results of the modeling are used to assess health risk. The concentrations that are used for the risk characterization are weighted concentrations based on the period of time in each place and existing Indoor Air Quality(IAQ) standards. The estimated concentration of toluene and formaldehyde for 10 years through the IIAQ model was 207.3 $ug/m^3$ and 36.4 $ug/m^3$ in indoors, and 55.9 $ug/m^3$ and 8.62 $ug/m^3$ in outdoors. These concentrations are lower than the existing IAQ standards. The estimated carcinogenic risk of formaldehyde is up to 1.05E-03 for the adult male group and exceeds 1E-06 for all receptor groups. This value means that cancer could affect one person out of 1000. The estimated non-carcinogenic risk of toluene was lower than 1, which means that there was no serious non- carcinogenic risk. The result of modeling shows that using low emitting indoor sources is the most effective strategy for both formaldehyde and toluene. This risk assessment suggests that the total exposure levels of existing IAQ standards may cause serious carcinogenic risk. In order to avoid uncontrolled risk, it is suggested that the current IAQ standards should be adjusted by taking into account the total amount of exposure from all exposure pathways from indoor and outdoor sources.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.265-274
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• 2016

Purpose: The aim of this study was to evaluate relationship between worker's ophthalmoxerosis symptom and IAQ (Indoor Air Quality) variation after planting indoor plants at newly-built office building. Methods: We selected a new office building located in Sejong-si and occupants who work in the Office for study. The indoor air pollutant was investigated according to applying indoor plants. The indoor air quality of the new building was evaluated by measuring volatile organic compounds (VOCs), aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). Results: There was VOCs' reduction effect according to placing indoor plants because the concentration of VOCs in newly-built government office (Sejong-si) was highly decreased when the indoor plants was placed at the office. The occupants' SBS (Sick Building Syndrome) symptoms score was gradually decreased in accordance with applying indoor plants. However, SBS symptoms score was increased when the office was not applied indoor plants. There was not statistical significance in workers' dry eye questionnaire results. Conclusions: There was reduction effect of indoor air pollutant in applied indoor plants office. Also, in case of questionnaire results of ophthalmoxerosis and SBS (Sick Building Syndrome) symptoms score were showed positive effect. This study is needed longer-term study because of complements of difference of individual sensitivity and there are some limitations due to field survey research.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.230-235
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• 2009

The Desiccant air conditioning system has been designed as the industrial dehumidifier under the leadership of developed countries, considering CFC problems in 1990, indoor air quality(IAQ) and outdoor air intake rates. This could make the technical differences between them and us. Nowadays, domestic technology has been developed in some parts but there still remain many challenges to be managed. In this study, these tasks would be handled according to the desiccant air conditioning system market and prospects.