IoT 기반 교실 내 벽면 녹화를 통한 실내공기질 개선 효과 평가

양호형,곽민정,정나라,김호현 한국냄새환경학회 2020 실내환경 및 냄새 학회지 Vol.19 No.4

In this study, the effect of improving indoor air quality according to the installation of plants was evaluated in classrooms where students spend much time. The purpose was to prepare sustainable and eco-friendly measures to improve the indoor air quality of school classrooms. A middle school in Bucheon was selected as an experiment subject, and IAQ monitoring equipment based on IoT was installed to monitor indoor air quality. After measuring the basic background concentration, plants and air purifiers were installed and the effects of improving indoor air quality using plants and air purifiers were evaluated based on the collected big data. As a result of evaluating the effects of indoor air quality improvement on the installation of plants and air purifiers, the reduction rates of PM10 and PM2.5 in descending order were plant- and air purifier- installed classes, air purifier-installed classes, and plant-installed classes. CO2 levels were reduced in the classrooms with only plants, and increased in two classrooms with air purifiers. The increase in CO2 concentration in the classrooms with plants and air purifiers was lower than in those with only air purifiers.

Analysis of Factors Influencing Indoor PM2.5 and CO2 Concentrations in Households using IoT Technology after Indoor Garden Installation

양호형,곽민정,김광진,김호현 인간식물환경학회 2022 인간식물환경학회지 Vol.25 No.6

Background and objective: Plants are a natural and environmentally friendly way to improve indoor air quality. To evaluate indoor air quality, it is important to continuously measure and identify the influencing factors. This study aimed to identify the factors affecting PM2.5 concentration in indoor spaces with indoor garden installations. Methods: Factors influencing the concentration of indoor, airborne PM2.5 were monitored based on Internet of Things (IoT) technology. Ten households in South Korea were surveyed and categorized into Groups A (households without an indoor garden) and B (households with an indoor garden). An IoT-based device was used to monitor the indoor PM2.5 concentration and several environmental factors, including the outdoor PM2.5 (μg⋅m-3) and carbon dioxide (mL⋅m-3) concentrations, temperature (°C), and relative humidity (%). Further, the seasonal (spring, summer, fall, and winter) and temporal (dawn, morning, afternoon, and evening) variations in indoor PM2.5 concentration were monitored. Results: The indoor PM2.5 concentration decreased from 17.7 μg⋅m-3 to 16.7 μg⋅m-3, and from 15.5 μg⋅m-3 to 12.5 μg⋅m-3 in Groups A and B, respectively. A regression analysis showed that the indoor PM2.5 concentration was not significantly affected by the installation of the indoor garden (living rooms: p = .1577; kitchen: p = .4974); however, was influenced by the outdoor air conditions, as well as seasonal and temporal factors. Additionally, a subgrouping model demonstrated a statistical relationship between indoor garden installation and the environmental factors. Conclusion: These findings can assist in establishing guidelines for indoor air quality management.

교사 내 플랜트 모델 유형별 적용에 따른 공기질 변화

양호형,김형주,방성원,조흔우,이형석,한승원,김광진,김호현 한국환경보건학회 2023 한국환경보건학회지 Vol.49 No.6

Background: Adolescents are relatively more sensitive than adults to exposure to indoor pollutants. The indoor air quality in classrooms where students spend time together must therefore be managed at a safe level because it can affect the health of students. Objectives: In this study, three types of green-wall models were applied to classrooms where students spend a long time in a limited space, and the resulting effects on reducing PM were evaluated. Methods: In the middle school classrooms which were selected as the experimental subjects, IoT-based indoor air quality monitoring equipment was installed for real-time monitoring. Three types of plant models (passive, active, and active+light) were installed in each classroom to evaluate the effects on improving indoor air quality. Results: The concentration of PM in the classroom is inf luenced by outdoor air quality, but repeated increases and decreases in concentration were observed due to the inf luence of students’ activities. There was a PM reduction effect by applying the green-wall model. There was a difference in PM reduction efficiency depending on the type of green-wall model, and the reduction efficiency of the active model was higher than the passive model. Conclusions: The active green-wall model can be used as an efficient method of improving indoor air quality. Additionally, more research is needed to increase the efficiency of improving indoor air quality by setting conditions that can stimulate the growth of each type of plant.

IoT 기반 바이오필터시스템이 설치된 지하역사 실내공기질 영향 요인 분석

양호형,김호현,전보일,안선민 한국환경보건학회 2021 한국환경보건학회 학술대회 자료집 Vol.2021 No.2

IoT 기반 지하역사 내 바이오필터시스템 설치에 따른 실내공기질 변화 및 영향 요인 분석

양호형(Ho-Hyeong Yang),김형주(Hyung-Joo Kim),방성원(Sung-Won Bang),조흔우(Heun-Woo Cho),김호현(Ho-Hyun Kim) 한국환경보건학회 2021 한국환경보건학회지 Vol.47 No.5

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A biofilter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM10, PM2.5, and CO2 increased during rush hour according to the change in the number of passengers, and PM10 and PM2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM2.5 in the subway station were the outdoor PM2.5, platform PM2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

대중교통차량 실내공기질 측정 신뢰성 확보를 위한 공정시험방법 마련

김호현,양호형,이정훈,강상현,김태현,김승열 한국냄새환경학회 2020 실내환경 및 냄새 학회지 Vol.19 No.1

The purpose of this study is to provision the standard method for ensuring the reliability of measuring indoor air quality in public transportation. The objective is to determine the difference in the measured concentration values according to various conditions. These variables include measurement conditions, measurement equipment, measurement points, and measurement time. The value differences are determined by measuring the PM10 and CO2 concentration of subways, and express buses and trains, which are targets of indoor air quality management. The concentration of CO2 was measured by the NDIR method and that of PM10 was measured by the gravimetric method and light-scattering method. Statistically, the results of the concentration comparison according to the measurement points of the public transportation modes were not significantly different (p > 0.05), and it is deemed that the concentration is not affected by the measurement points. In terms of the concentration analysis results according to the measurement method, there was a difference of the concentration between the gravimetric and light scattering method. In the case of the light scattering method, the concentration differed depending on whether it was corrected with standard particles in the laboratory environment.

교실 내 벽면녹화를 통한 초미세먼지(PM2.5) 저감 효과 평가

최치구(Chi-Ku Choi),양호형(Ho-Hyeong Yang),김호현(Ho-Hyun Kim),권혁구(Hyuk-Ku Kwon) 한국환경보건학회 2023 한국환경보건학회지 Vol.49 No.4

Background: The indoor air quality of classrooms, in which the capacity per unit area is high and students spend time together, must be managed for safety and comfort. It is necessary to develop an eco-friendly indoor air quality reduction method rather than biased management that relies solely on air purifiers. Objectives: In this study, plants and air purifiers were installed in middle school classrooms to evaluate the indoor PM2.5 reduction. Methods: Four middle school classrooms were selected as test beds. Air quality was monitored in real-time every one minute using IoT equipment installed in the classrooms, corridors, and rooftops. After measuring the background concentration, plants and air purifiers were installed in the classroom and the PM2.5 reduction effect was analyzed through continuous monitoring. Results: After installing the plants and air purifiers, the average PM2.5 concentration was 33.7 μg/m3 in the classrooms without plants and air purifiers, 25.6 μg/m3 in classrooms with plants only, and 21.7 μg/m3 in classrooms with air purifiers only. In the classroom where plants and air purifiers were installed together, it was 20.0 μg/m3. The reduction rates before and after installation were 4.5% for classrooms with plants only, 16.5% for classrooms with air purifiers only, and 27.6% for classrooms with both plants and air purifiers. The I/O ratio, which compares the concentration of PM2.5 in classrooms with corridors and outside air, also showed the lowest in the order of plants and air purifiers, air purifiers, and plant-only classrooms. Conclusions: The PM2.5 reduction effect of using plants was confirmed, and it is expected to be used as basic data for the development of environmentally-friendly indoor air quality improvement methods.

화학사고 피해복구 종료 시점 결정을 위한 려빙랩 활용

길호현,곽윤경,전보일,고수진,박희진,양호형 한국환경보건학회 2021 한국환경보건학회 학술대회 자료집 Vol.2021 No.2

대중교통수단 객실 내 휘발성유기화합물류 거동 특성

곽윤경(Yoon-kyung Gwak),이정훈(Jeong-Hun Lee),전보일(Bo-il Jeon),양호형(Ho-Hyeong Yang),김호현(Ho-Hyun Kim) 한국환경보건학회 2020 한국환경보건학회지 Vol.46 No.2

Objective: This study is aimed at investigating indoor air quality on public transportation (subway, train, and bus) according to changes in season and time. Methods: We evaluated TVOC and HCHO on public transportation based on the un-controlled parameters of the Ministry of Environment. We also measured temperature and humidity since they affect the concentration of TVOC and HCHO. For public transportation classification, subway lines were classified into Lines 1 to 4. Additionally, trains were classified as ITX and KTX. Results: When comparing summer and winter on public transportation, the concentrations of TVOC and HCHO did not show any particular tendency. However, the concentrations of TVOC and HCHO during traffic congestion was higher than levels during times of non-congestion on most public transportation. In summer and winter, the measurement results for temperature and humidity showed a normal range, so temperature and humidity did not affect the concentrations of TVOC and HCHO. In the case of TVOC, TVOC concentrations on new trains were found to be relatively higher than on older ones, but there was no statistically correlation. Conclusions: A survey was conducted on the indoor air quality on public transportation. This study also analyzed data based on TVOC and HCHO for designing policies and managing indoor air quality.