• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.1-6
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• 2014

With increasing number of citizen using subway stations everyday, safety, health and comfort of passengers and occupants became an important social issue. Considering the fact that various physical variables and pollutants are related to indoor air quality (IAQ) which may cause health problem, IAQ need to be closely monitored and controlled in multiple locations in subway stations. This study is a continuation of the previous studies and delay induced in wireless-wired network is experimentally evaluated and the risk involved is assessed. In doing that, a key parameter is identified to be the network delay in different network media. Application of information-theoretic measure to assess the risk in network delay is then discussed. The idea is based on the general principles of engineering design and their applications to quantification of uncertainty in network delay. Experimental results show that more risk is involved in wireless data communication. Efficient and fast conversion of transmission data in both LonWorks/IP server and ZL converter is also noted.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.2
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• pp.142-148
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• 2007

The purpose of this study is to suggest the effective ventilation strategies and control methods that can minimize energy cost maintaining acceptable IAQ level in apartment house. The effects of the air-cleaning and heat-recovery ventilation system on IAQ under various operating conditions are investigated based on the experimental and CFD analyzed results. The results can be summarized as follows. (1) When a ventilator is not operated, the concentration of several pollutants may highly show in the house even though environment-friendly building materials are applied. Therefore, a mechanical ventilation system is required to obtain proper ventilation. (2) The pollutant concentration is noticeably deceased under air-cleaning/ventilation mode of air-clinic system, however, pollutant of kitchen is stagnant, because fresh air is not carried into the kitchen. (3) When air-clinic system is only equipped at master bedroom and living room, the system does not effectively deliver fresh air throughout the whole house, and then high pollutant concentration is obtained in each room. In contrast the average pollutant concentration meets the guideline when air-clinic system is installed at each room. (4) The air-cleaning/ventilation mode significantly affects on room ventilation in comparison with ventilation mode only.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.3
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• pp.397-412
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• 1996

This study aims to present the fundamental strategies to improve the Indoor Air Quality (IAQ) in apartment buildings. To investigate the concentration of indoor air pollutants such as radon, formaldehyde, and VOCs, both the document survey and the field measurement were conducted. In addition, to identify the source of the air pollutants, the laboratory experiment was carried out for various building materials. Finally, the minimum period to be reserved befor3e building occupation to ensure healthy IAQ, which largely depends on the ventilation rates, was simulated using a simple compuer program. The results of this study can be summarized as follows: 1. In case of newly-constructed apartment houses, concentrations of formaldehyde, VOCs and radon were found to exceed the standard. Meanwhile, at existing apartment houses, concentrations of VOCs, particularly toluene and xylene, highly exceeded the standasrd level. Concentrations of formaldehyde and radon, however, had been lowered according to the duration of occupation. 2. The laboratory experiment of concentration of pollutants per square meter of building material surface area showed that radon gas was much emitted from the gypsumboard; formaldehyde from flooring and wallpaper; and VOCs from paints and kitchen furnishings. The emission rates of formaldehyde and VOCs were proportional to air temperature. 3. According to the simulation of the minimum period to be reserved before occupation, newly-constructed airtight houses required about 190-200 days, and naturally ventialted houses with fully-open-windows required about 20-45days, in order to keep the level of radon gas lower than standard. Therefore, with the current practice, the date of occupation should be delayed for about 15 days.

• KIEAE Journal
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• v.10 no.3
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• pp.3-10
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• 2010

As indoor air quality directly affects health and comforts of the residents, researchers from different countries have continued to explore criteria by which indoor air quality can be indicated in a scientific and quantitative manner over the past several decades. However, there are many possibilities that can deteriorate indoor air quality. Due to the uncertainty of influence factors, it is quite difficult to develop a correct evaluation model and quantitative method. Furthermore, the effects from the indoor air pollutants have different levels, leading to the difficulties to apply the regular standard. This study aims to propose evaluation criteria by using the FD-AHP analysis. Obtained findings will be beneficial to construct apartment buildings, commercial buildings and others health performance evaluation framework.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.19 no.6
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• pp.342-351
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• 1990

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.7
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• pp.688-693
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• 2005

Nowaday the natural ventilation rate decreases because the apartment housing is being air-tight. Therefore, Indoor Air Quality (IAQ) and indoor environment grow worse. Especially, Formaldehyde (HCHO), Volatile Organic Compounds (VOCs) which is emitted from the building materials and coating material etc. occur Sick House Syndrome that cause negative impact on resident's respiratory system and body. Therefore in construction field, it will be a important issues that development of a ventilation system with high effectiveness which can exhaust the contaminant out of the building quickly. In this research we evaluated 'wall attachable duct-less Heat Recovery Ventilation (HRV) system with air cleaning function'. We executed a synthetic evaluation about indoor air environment under various operating condition installing the system in real scale apartment house that is built in Anyang city. HRV system with air cleaning function showed good performance by removing HCHO, VOCs with less ventilation energy.

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.444-456
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• 2020

Objectives: This study developed an index for the indoor air quality management of city buses to allow the provision of indoor air quality information to city bus users. Methods: Nine city buses in Seoul were measured for PM₁₀, PM_2.5, CO₂, temperature, and relative humidity through IoT sensors. Big data collected through the sensors was analyzed to identify indoor air quality on city buses and graded through the index. Results: As a result of dividing the measured city bus data into five grades through the IAQ index, PM₁₀ was rated "good" for 30.4% of the total measured values, and 9.2% were rated "risky". For PM_2.5, 67.7 percent were rated "good" and 0.4 percent were rated "risky". For CO₂, 0.9% were 'good' and 1.1% were 'risky'. The results of the classification through the IAQ index for city buses showed that the impact of good, normal, sensitive, bad, and dangerous were 2.7, 38.8, 46.0, 12.4, and 0.1%, respectively. According to the analysis by measurement area, Seocho-gu, Gangnam-gu, Seongdong-gu, Gwangjin-gu, and Dobong-gu are "normal" and other areas (Seodaemoon-gu, Jongno-gu, Yongsan-gu, Jung-gu, Seongbuk-gu, Dongdaemun-gu, Junggye-gu, Gangbuk-gu, and Nowon-gu) are all rated "sensitive". Conclusions: When analyzing cases where PM₁₀ and CO₂ indices are in the "bad" zone, the concentration is generally found to increase during rush hour, during which there are a large number of passengers. It is expected that indoor air quality management in vehicles will be necessary during rush hour.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.273-278
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• 2005

This study was performed to investigate the characteristics of distribution for airborne bio aerosol in 11 public facilities in Seoul from June to July. The collected samples are total suspended bacteria in indoor and outdoor Anderson six stage air sampler by the IAQ standard method of Ministry of Environment in Korea. The concentration of total suspended bacteria in the theater higher than IAQ standards. As the results of the survey, the most high indoor air mean concentration of bacteria $1273CFU/m^3$ was theater and the most high outdoor air mean concentration of bacteria $^229 CFU/m3$was Kindergarten. The mean concentration of bacteria in the theater was higher than the IAQ standards established by the Ministry of Environment, Republic of Korea. Moreover, this study was for investigation a part of indoor air pollution condition in public facilities. It means that this study can't represent fDr all of public facilities. Therefore, we suggest that long and middle term country plan for management of IAQ should be established through long-term and continuous investigation of IAQ condition. Also above consideration in mind, it is suggest that the research for source contribution of the results on these need further study.

• Journal of environmental and Sanitary engineering
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• v.18 no.1
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• pp.51-57
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• 2003

Indoor air quality(IAQ) in workplace and residential environments has been concern of people. Recently, Ministry of Environment in Korea has recognized the potential risk on the healthy effect related to indoor air pollution at home. Therefore, the purpose of this study was performed to measure the indoor air pollutants of IAQ at different homes and investigate to compare the perception of IAQ recognition at home from questionnaire survey in Seoul. We estimated the IAQ of selected 6 homes based on site region and housing type. The indoor air pollutants and parameters such as temperature, relative humidity, respirable suspended particulate matter($PM_{10}$), formaldehyde(HCHO), total bacteria counts, carbon monooxide(CO) and carbon dioxide($CO_2$) were monitored for summer and winter. In monitoring results, the respirable suspended particulate matter(($PM_{10}$) and indoor airborne bacteria level of home 5 and 6 were higher than the standard of the public $150{\;}{\mu}g/m^3$ and $500{\;}{\mu}g/m^3$, the level formaldehyde(HCHO) was exceed 0.1 ppm of the standard of Korea at all monitored homes. In statistics analysis, we could find a correlation between the building age and the concentration of CO, TBC were significant at 0.01 level and Relative Humidity was significant at 0.05 level for summer. Finally, the important air pollutants of IAQ in home were HCHO and total bacteria counts(TBC). And we performed a questionnaire survey of 500 people about their awareness for the importance of IAQ in our home during same period. In results, all most response of occupant has recognized the importance of IAQ at home. Therefore, it can be concluded that the IAQ of selected 6 home studied was perceived as acceptable, it is recommended that the government related IAQ was suggested the guideline and control of IAQ problems, and the occupants need to be effort to reduce the exposure of sources to undesirable pollutants.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.69-76
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• 2017

Indoor Air Quality(IAQ) affects physical and mental state of person who is residing indoor. Also, it manages daily life condition of Indoor Air in the building. According to the study, office workers spend 23 hours and 12 minutes, about 97% of his/her day indoor. Therefore, Indoor air quality affects not only the health of the person whose staying inside for a long hours but also the productivity and efficiency of work. This study conduct investigations on employees' awareness of indoor air quality of office in university. By doing so, we are able to determine current situation and provide basic data of improvement for derived problems. As a result, most of the respondents were not satisfied with ventilation and moisture which are elements of Indoor Air Quality. These led people to struggle with symptoms of health. Therefore, to improve the indoor air quality of a university office, it is necessary to exchange the air six times an hour according to recommendation of Refrigeration and Air Conditioning Engineers (ASHRAE)in the United States. Also, plan for Ventilation system that consider temperature, humidity and air flow indoor shall be provided for high quality conformability. furthermore, It is necessary to consider the multilateral in factors of generation of revenue through health care savings of workers and improvement of productivity.