• 환경위생공학
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• 제23권2호
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• pp.35-45
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• 2008

In order to recommend criteria for the administration law on indoor air quality, this study was conducted to examine the distribution and the concentration of indoor air pollutants ($PM_{10},\;CO_2$, CO, HCHO, TBC, $NO_2$, Rn, VOCs, asbestos, $O_3$) in public facilities in the Chung-Nam area. The concentrations of indoor air pollutants were obtained from sixty seven public facilities such as a cinema, an office, a restaurant, a theater and an academy. This study was performed from August to December, 2005. The results of this study showed that the concentrations of indoor air pollutants such as $PM_{10},\;CO_2$, CO, HCHO, TBC, Rn and $O_3$ were less than the recommended limits. However, the average concentration of VOCs was $521.73{\mu}g/m^3$ (GM : $221.69{\mu}g/m^3$), which was higher than the recommended limit of $400{\mu}g/m^3$. Moreover, the average concentration of $NO_2$ was 345.66ppb (GM : 69.95ppb), which was higher than the recommended limit of 50 ppb. The correlation between the concentrations of indoor air pollutants and the type of facilities with respect to $CO_2$, TBC and Rn was statistically low (p<0.05). However, the correlation was high in terms of the CO and $O_3$ concentrations (p<0.01). No relationship between the indoor air pollutants and the type of facilities was observed for $PM_{10}$, VOCs and $NO_2$. The year of construction was compared to the concentrations of indoor air pollutants. Specifically, when the construction date was less than 3 years, the HCHO, VOCs and TBC concentrations were $44.75{\mu}g/m^3,\;555.07{\mu}g/m^3$ and $337.79CFU/m^3$, respectively. These concentrations were $120{\mu}g/m^3$ and $211.84CFU/m^3$ higher for VOCs and TBC than the concentrations obtained from the facilities more than 3 years. However, the concentration of HCHO was similar between the facilities older and younger than 3 years of age. Year, temperature, humidity and indoor air pollutant correlation analyses showed that temperature and humidity, temperature and TBC, temperature and $O_3,\;PM_{10}$ and $NO_2$, HCHO and VOCs, $CO_2$ and Rn had positive relationships. However temperature and Rn, humidity and $CO_2,\;CO_2$ and $O_3,\;O_3$ and Rn had negative relationships. Accordingly, it will be necessary to manage the factors affecting indoor air quality so that the residents can have a more comfortable and healthier living environment. Ultimately, the results of this study are expected to be utilized as baseline data.

• 설비공학논문집
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• 제18권7호
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• pp.563-570
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• 2006

We investigated the emission characteristics of gaseous organic contaminants from building materials and newly constructed apartments. The emission test for building materials was done with small chamber method, and field measurements in newly constructed apartment were carried out by Korea Standard Test Method for Indoor Air Quality. First, the emission test by small chamber showed that the TVOC emission from building materials was much higher than formaldehyde. On the other hand, as expected, considerably high concentration of both TVOC and HCHO was detected in the new apartment.

• International Journal of Air-Conditioning and Refrigeration
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• 제13권2호
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• pp.89-98
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• 2005

In this study, indoor VOCs concentration emitted from floor and furniture was measured after the installation of floor and furniture in a real residence. With the measured data, prediction method and predication equations for indoor concentration of each VOCs and BTEX were developed. The following conclusions were drawn from this study. First, according to the predicted results of concentration decrease of BTEX (benzene, toluene, ethylbenzene, m,p,o-xylene) after the installation of floor in a real residence, prediction equation can be expressed using exponential function. Second, in case of floor, more reliable prediction equation can be obtained by using cumulative value of indoor concentration than by using just hourly measured value directly. Indoor concentration of benzene can be expressed as $y=408.52(1­e^{-00031{\times}time})$ with $R^2$ of 0.94 which is significantly high value. Third, toluene showed the highest concentration in case of furniture installation indoors, and it needed the longest time for concentration decrease. However, other substances except toluene showed constant concentration throughout the measurement period. Fourth, in case of furniture installation indoors, prediction equation of toluene concentration decrease is estimated to be $y= 3616.3{\times}e^{(-0.1091{\times}time)}+513.96{\times}e^{(-0.0006{\times}time)}\;with\; R^2$ of 0.95 which is significantly high value.

• 한국가구학회지
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• 제23권4호
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• pp.381-387
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• 2012

Utilization of underground floor is becoming the main issue of our society to maximize and diversify the potential of recent urban space. It has brought about the changes of underground floor. Recently there are lots of huge bookstores in these underground floor. Bleach, adhesive and ink used for manufacturing books pollute indoor air in bookstore. Therefore, the purpose of this study is to analyze indoor air quality in these large bookstores. Concentrations of carbon dioxide and formaldehyde in three large bookstores in Seoul were measured by presence and type of books and distance of main entrance which is well-ventilated. According to the data, space that places lots of volumes measured higher concentration of formaldehyde than that of non-existence books. Children's book section was measured more concentration of formaldehyde than other book section. Closer main entrance near outside, lower concentration of formaldehyde was measured. Concentration of carbon dioxide was affected by the number of people in bookstore.

• 한국환경보건학회지
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• 제35권6호
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• pp.468-477
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• 2009

To evaluate the current indoor air quality condition of private academic facilities in Korea and investigate its association with subjective symptoms of student residing at the same academic facilities, air quality monitoring was carried out in total of 20 academic facilities located in Seoul, Daejon and Chungnam from the beginning of January to the end of April, 2009. To assess the air quality condition of academic facilities, 6 air pollutants with temperature and humidity were measured simultaneously inside and outside of academic facilities. The rate of exceeding the Indoor Air Quality (IAQ) guideline concentrations in 6 air pollutants were 5%, 85%, 15%, 5%, 10% and 30% for CO, $CO_2$, PM10, HCHO, TVOCs and TBC, respectively. A questionnaire on 16 subjective symptoms related to indoor air quality was given to 342 students who studied at the 20 academic facilities. The most frequent symptom of students was 'I feel easily tired or sleepy', and this was followed by 'I feel muscular pain or stiffness on shoulder, back and neck'. The association of net difference (subjective symptoms at the academic facility - subjective symptoms of the usual situation) with air pollutants was analyzed using spearman rank correlation. In logistic analysis using proportional odds method, the students whose indoor air concentration of HCHO was ${\geq}60{\mu}g/m^3$ hadsignificant odds of having more subjective symptoms of 'My eyes are dry or feel irritated or itching' (OR=5.026: CI=1.587-15.911), 'I feel easily tired or sleepy' (OR=2.956: CI=1.072-8.152), 'I lose my concentration and I feel my memory is falling' (OR=7.745: CI=1.938-30.955) and 'I feel dizzy' (OR=4.424: CI=1.292-15.149) than those of <$60{\mu}g/m^3$.

• 한국환경보건학회지
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• 제32권2호
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• pp.132-139
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• 2006

Number of aerosol, CO, $CO_2$ and TVOC after one-, two-, three-cigarettes smoking were monitored with time every 10 minute for 180 minutes in the seminar room (volume $51.1m^3$) when poorly-ventilated. IAQ monitor (IAQRAE, model PGM-5210) and PortCount (TSI, model 8020) were used for monitoring. Aerosol was decreased with exponential decay equation and it was estimated that number of aerosol would be long suspended (one cigarette 75/cc. two cigarettes 66/cc, three cigarettes 141/cc by 8hrs after smoking). While CO was also decreased with exponential or linear decay equation and correlated with number of aerosol strongly, TVOC and $CO_2$ were increased with linear equation in accordance with time lag. Most of TVOC and $CO_2$ were above standard levels of Korean Indoor Air Quality (Ministry of Environment) without regarding number of cigarettes. When naturally ventilated, all of CO, $CO_2$ and TVOC concentrations were dramatically decreased below standard levels of Korean Indoor Air Quality.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.13-18
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• 2023

A subway station is a prominent multi-purpose facility where the quantitative management of fine dust, generated by various factors, is conducted. Recently, eco-friendly air purification methods using air-purifying plants are being discussed, with the focus on biofiltration through vegetation. Previous research in this field has confirmed the reduction effects of transition metals such as Fe, which have been identified as harmful to human health. This study aimed to identify the sources of fine dust dispersion within subway stations and derive an efficient operational strategy for air-purifying plants that takes into account the behavior characteristics of fine dust within multi-purpose facilities. The experiment monitored regional fine dust levels through IAQ stations established based on prior research. Also, the data was analyzed through time-series and correlation analyses by linking it with passenger counts at subway stations and the frequency of train stops. Furthermore, to consider energy efficiency, we conducted component-specific power consumption monitoring. Through this study, we were able to derive the optimal operational strategy for air-purifying plants based on time-series comprehensive analysis data and confirm significant energy efficiency.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.287-290
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• 2006

The purposes of this study were to make clear the present condition of the TVOC and HCHO concentration after remodeling in apartment houses and to analyze the relation of concentrated ascension and remodeling elements. The field measurements of TVOC and HCHO concentration were carried out in 4 subject apartment houses according to the Korea Test Method Standard for Indoor Air Quality. The results are as follows; the TVOC concentration after remodeling ranged from mean 0.35ppm to mean 5.08ppm and increased of 0.35$^{\sim}$5.08ppm. The concentration of 3 subjects exceeded the Indoor Air Quality Management standard for the newly-built apartment houses (0.7ppm). The HCHO concentration after remodeling ranged from mean 0.13ppm to mean 0.43ppm and increased of 0.06$^{\sim}$0.26ppm. The concentration of 2 subjects exceeded the Standard (0.16ppm). As results of analysis on the relation of concentrated ascension and remodeling elements, the amount and the types of finishing materials and adhesives affected concentrated ascension. Also, production method for installed or purchased furniture had certain effect on the TVOC and HCHO concentration ascension.

• 한국환경보건학회지
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• 제49권4호
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• pp.183-189
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• 2023

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 PM_2.5 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 PM_2.5 reduction effect was analyzed through continuous monitoring. Results: After installing the plants and air purifiers, the average PM_2.5 concentration was 33.7 ㎍/m³ in the classrooms without plants and air purifiers, 25.6 ㎍/m³ in classrooms with plants only, and 21.7 ㎍/m³ in classrooms with air purifiers only. In the classroom where plants and air purifiers were installed together, it was 20.0 ㎍/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 PM_2.5 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 PM_2.5 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.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1213-1219
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• 2008

This experimental study was to analyze thermal comfort and indoor air quality(IAQ) with ventilation and humidification in the classroom when system air conditioner was operated. The thermal comfort was estimated by the PMV index and the concentration of $CO_2$ and total suspended particle(TSP) were measured and compared with ventilation and humidification. As a result, the class room temperature distribution was $2{\sim}5^{\circ}C$ low during operating ventilation system and humidification. At 60% RH, PMV values of measuring points were ranged from +0.5 to -0.5 indicating optimal the range of thermal comfort. The average concentration of $CO_2$ gas and TSP were reduced 645 ppm, 0.17 mg/$m^3$ respectively, during operating the ventilation system. From the results, to maintain comfortable environment in the heated classroom, the ventilation and humidification were needed in winter season.