In order to capture the indoor CO₂ gas from public indoor spaces, a commercial zeolite(4A) was modified with alkali metals useful for adsorption. The prepared sorbents showed somewhat improved adsorption capacity. A few isotherm models were reviewed to characterize the adsorption mechanism of test sorbents. Sips model was found the most appropriate for low level indoor CO₂ adsorption, but revealed a significant error in low pressure regimes and required numerical analysis for quantitative evaluation. Thus, a parameter(qm) in the equation was empirically recorrelated with a operation temperature. As a result, the final model equation including a simple linear function presented less errors for evaluation of the potential capacity of adsorption.

The objective of this study was to estimate distribution of hazardous air pollutants and volatile organic compounds at diverse indoor areas in school. The indoor air samples were collected at 19 school in three different areas of southern Korea region from September to October 2009. The concentrations of PM-10 and formaldehyde in all sampling sites were below indoor air quality guideline of the Ministry of Education, Science and Technology. The CO₂ level and TBC (total bacteria count) were higher than the guideline for 4 sites and 12 sites, respectively. The concentration of TVOC for 23 sites exceeded the guideline. Also, TVOC level of metropolitan sampling sites were somewhat higher than small and medium-size city sampling sites. The concentration of indoor air pollutants affected by various conditions such as season, region, and indoor/outdoor environment. This study result shows that concentration of several pollutants such as CO₂, TBC, and TVOC were higher than the guideline for some sampling sites. Therefore, it is necessary to manage indoor air quality and establish effective emission reduction strategies regard for characteristics of each school.

To research indoor air pollution in the training rooms of technical high school, the temperature, air current, humidity, CO₂, CO, O₃ were measured by Indoor Climate System(ICS 500, Casella, UK) at each classroom, scientific laboratory, electricity training room, electronic equipment training room and welding training room. The change of air pollution concentration and its correlation were additionally compared and analyzed. At closed small space such as classroom, scientific laboratory, electronic equipment training room and electricity training room, the CO₂ concentration was obtained to the 2,030ppm(max.), which is higher than notified and recommended standard value(1,000ppm) by Ministry of Health and Welfare and Ministry of Environment, Korea. At welding training room where is larger and more ventilated than general classroom, CO concentration was measured to the 3.6ppm, which is higher than average 1ppm measured at other training rooms. The concentration of O₃ is not yet regulated from the standards of underground air quality, but at welding training room it was measured as 0.11ppm(max.) that is higher than 0.01ppm measured at other training rooms. The higher value of temperature, air current, radiant temperature and CO₂ concentration was shown at scientific laboratory, electricity training room and electronic equipment training room where are closed and same with the scale of classroom. And the higher concentration of CO₂, CO and O₃ was shown at welding training room which was opened larger classroom. The indoor air pollution by CO₂, CO and O₃ may directly affect on the training room where many students work at a small space, and they should be controlled appropriately. Each experimental formulas were made for the estimation of CO₂, CO and O₃ concentration depending on some kinds of variables at each training room. It is found that indirect ventilation system with a filter will be needed for regular and constant ventilation and the ventilation system should be applied to protect and make clean and comfortable environment of training rooms at technical high school.

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. Toluene and nitrogen dioxide (NO₂) concentrations of residential indoor and outdoor were simultaneously measured and compared in 16 houses, using passive samplers during every 3 days for 60 days. Concentrations of toluene and NO₂ were analyzed by gas chromatography and spectrophotometer, respectively. Using a mass balance model, penetration factor (ventilation rate divided by sum of ventilation rate and deposition constant) and source generation factor (source generation rate divided by sum of ventilation rate and deposition constant) were calculated by multiple indoor and outdoor measurements. The mean contributions of toluene of indoor and outdoor sources on residential indoor air quality were estimated to be 31.01% and 67.00%, respectively. On the other hand, mean contributions of NO₂ were 58.93% and 41.06%, respectively. These results could be explained that contributions of indoor and outdoor air pollutants sources are different to residential indoor air concentrations. In conclusion, contributions of outdoor air and indoor sources affecting indoor air quality were effectively characterized using multiple indoor and outdoor measurements.

This paper presented experimental results for photocatalytic air cleaner removal performance for malodorous compounds generated from rest room. Photocatalytic oxidation (PCO) efficiency was up to 80∼ 90% for NH₃ in chamber, 29.3% for H2S, 79.6% for CH3SH, 58.8% for DMDS individually. PCO efficiency for DMS(Dimethy Sulfide) and DMDS(Dimethyl Disulfide) were relatively lower than that of NH₃ and CH3SH, this results indicate that DMS and DMDS removal process were effected by by-products of photocatalytic oxidation and humidity. Ozone was relatively low (below 5ppb) under the test conditions through photocatalytic oxidation. It is necessary to test a reliability of the air cleaner for a longtime under the various indoor conditions. But, prototype photocatalytic air cleaner will promise useful air cleaner for indoor air quality applications.

In this study the real situation of apartment house in seoul is reproduced with multi-zone modeling program CONTAM2.4. This model include disinfection system which is consist of dilution, filtration, UVGI(ultra violet germicidal irradiation). It's energy consumption was also analyzed through the linked model of CONTAM and TRNSYS according to the combination of components. The comparison of total energy consumption through energy analysis revealed that adjusting the air change rate of the UVGI air sterilizer to maintain the same indoor microbe removal capability was more advantageous in terms of energy consumption.

Indoor Lighting can be improved by using a refractive lens. This lens is a flat-plate, and patterns are engraved on its surface. The engraved patterns are designed to refract sun's rays. In this study, two patterns have been suggested. The one is designed to refract sun's rays in one direction. The another is designed to refract sun's rays in 4 directions. The designed patterns were machined with a diamond tool and engraved on an experimental Poly Methyl Meta Acrylate flat-plate. Optical experiments have been done by using a laser rays and natural sun's rays. The results showed that sun's rays refracted in one or 4 directions effectively. The refracted rays also improved indoor lighting.

The purpose of this study are to examin the level of temperature, relative humidity and pollutants at stock rooms in National Archives and to provide fundamental data in order to protect damage of archives. The survey of indoor air quality(IAQ) in stock rooms was performed in Busan National Archives in August and December 2007, and collected basic data, on level of them at stock rooms in National Archives that were published. The temperature and relative humidity in stock rooms were within the terms of national law of the public archives administration. The concentration of PM10 in stock rooms in National Archives exceeded 50 ㎍/m³, which is the guideline of national law for the public archives administration. The concentration of CO, SO₂, NO₂, O₃ and Formaldehyde in stock rooms did not exceeded the guideline of national law. The concentration of total volatile organic compounds was shown to exceed the guideline of natioanl law. Therefore, we suggest that a national plan for the management of IAQ at stock rooms in National Archives should be established through a long-term, continuous investigation

The hybrid cooling system of vapor compression system and naturally circulating coolin system using R-410a for indoor mobil tele-communication center(IMTC) is developed and its performance is experimentally studied. Its results are summarized as follows. First, cooling capacity of naturally circulating cooling system is proportional to indoor and outdoor temperature difference and it has max. 4,550 kcal/h at indoor and outdoor air temperature difference 15℃. Second, heat exchangers of evaporator and condenser should be designed and constructed to be able to get maximum refrigerant capacity by naturally circulating force and to enhance heat transfer by refrigerant. Third, cooling capacity of hybrid cooling system has optimum operating point according to refrigerant charging capacity and refrigerant charging capacity of naturally circulating cooling system is 30~50% more than vapor compression refrigeration system.

본 연구에서는 국내 돔경기장을 해석대상공간으로 선정하여 기존 공조방식과 국외 돔경기장에서 사용한 공조방식을 적용하여 겨울철 실내기류 및 온도분포를 분석하고, 열고온층을 해소하기 위한 방안으로 설치된 기류유인팬의 적절성을 검토하였다.

Exposure to nitrogen dioxide (NO₂) can produce adverse health effects. Various indoor and outdoor combustion sources make NO₂ the most ubiquitous pollutant in the indoor environment. Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. In the present paper, we used a mass balance model and regression analysis, penetration factor (ventilation rate divided by the sum of ventilation rate and deposition constant) and source strength factor (source strength divided by the sum of ventilation rate and deposition constant) were calculated using multiple indoor and outdoor measurements with 10 houses. Subsequently, mean contributions of indoor and outdoor sources were 28.86% and 81.09%, respectively, suggesting that both indoor and outdoor sources had contributions to indoor concentrations of NO₂.

The indoor level of phthalates in children-facilities was assessed in this study. The samples of house dust were collected at various children's facilities (40 day-care houses, 42 child-care centers, 44 kindergartens, and 42 indoor playgrounds) in summer (Jul~Sep, 2007) and winter (Jan~Feb, 2008) periods, and analyzed by GC-MS. The DEHP was detected in almost every sample (detection rate : 99%) and the detection rate of DnBP and BBzP was more than 80%. The average concentrations of DEHP, DEP, DnBP, and BBzP in house dust were 388 ㎍/g dust, 37㎍/g dust, 108㎍/g dust and 349㎍/g dust, respectively. The relationship between construction period and DEHP level was statistically significant. But, other factors such as flooring material, construction period and water leakage were not statistically significant relationship with phthalates levels. The Phthalate levels were similar or more higher than other the European country.

In this work, pellet type sorbents were prepared to control the low level indoor carbon dioxide with various physical compositions. In order to enhance the adsorption capacity, a few additives including alkali hydroxides were added to a commercial zeolitic sorbent by impregnation of alkali cation - Ca²⁺ through physical mixing and ion exchange. It was found that the binding materials such as dextrin or bentonite facilitating to form the granular sorbents would assist the adsorption capacity of sorbents. The ion exchange was more efficient for impregnation of alkalies, which showed better adsorption of gaseous CO₂.

the less-reported gaseous studies have primarily dealt with chemical process stream concentrations than indoor air quality (IAQ) concentration levels. Accordingly, the current study was conducted to establish the feasibility of applying visible-light-induced TiO₂ doped with sulfur (S) element to cleanse toluene and ehtyl benzene at IAQ levels. The S-doped TiO₂ was prepared by applying two popular processes and two well-known methods. For both target compounds, the two coating methods exhibited different photocatalytic oxidation (PCO) efficiency. Similarly, the two S-doping processes showed different PCO efficiency. These results indicate that the coating method and doping process are important parameters which can influence PCO efficiency. Meanwhile, it was found that the PCO efficiency of ethyl benzene was higher than that of toluene. In addition, the degradation efficiency of the target compounds increased as the relative humidity (RH) decreased. The PCO efficiency varied from 44% to 74% for toluene and from 68% to 95%, as the RH decreased. Consequently, it is suggested that with appropriate RH conditions, the visible-light-assisted photocatalytic systems can also become an important tool for improving IAQ.

Test methods of Korea Air Cleaning Association (KACA) and Association of Home Appliance Manufacturers (AHAM) for particle cleaning capacity performance of an indoor air cleaner were compared in terms of the conditions of the test particle generation, the range of particle measurement and the calculation methods for particle cleaning capacity, and types of the test particles. The performance test was conducted in a 30 m³ chamber with the same test specimen and the test particles of each test were generated until the number concentration of 0.3 ㎛ particles reached 2.2 × 108 #/m³. The performance test results showed that the cleaning capacity with the particles of higher surface area and volume density, regardless of the type of test particles, was higher than with those of lower and the capacity from calculation with 0.3～1 ㎛ particles was higher than with 0.3 ㎛ particles. Moreover, the cleaning capacity with the calculation of KACA method was lower than with that of AHAM method in spite of using the same test specimen.

According to the measurements at Seoul Metro subway, the sound level at the time of subway arrival ranged from 77.0 to 92.5 dB(A). The highest level was 92.5 dB(A) at Line-1, and the lowest level was 77.0 dB(A) at Line-5. The sound level of departure ranged from the lowest level of 82.9 dB(A) at Line-5 and the highest level of 95 dB(A) at Line-1. The indoor sound level at subway ranged from the lowest level of 87.2 dB(A) (Line-6) to the highest value of 92.1 dB(A) (Line-1). The results of this study also showed that the sound level at subway platform with Platform Screen Door(PSD) showed 81.8 dB(A) but 89.1 dB(A) without PSD. The sound reduction effect of PSD showed 7.3 dB(A) at platform. Consequently, the sound level in Korean subway was found to exceed the standard set for the American Public Transportation Association (85dB(A)).

Secondhand smoke (SHS) is one of major public health threats in morbidity and mortality. Several national and regional comprehensive smoke-free regulations have been implemented to prevent public health exposure, but not in Korea. The purpose of this manuscript was to review impacts of the national or regional smoke-free legislations on indoor air quality, health effects and smoking behaviors. Indoor air quality has been improved significantly after smoke free policy. Such improvement was measured by fine particulates and urinary cotinine. Respiratory and cardiovascular health effects were significantly improved after smoke free policy. This is an indirect evidence of association between secondhand smoke exposure and the health effects. Respiratory symptoms were improved as short as one month after smoke free policy. Smoke free policy was also associated with improved perception of danger of secondhand smoke. Reduction of smoking prevalence was also unexpected benefit of smoke free policy. As reviewed in this paper, smoke free policy can be beneficial to indoor air quality, health effects and smoking behaviors. Since Korea does not have comprehensive smoke free policy yet, it is strongly recommended to implement national comprehensive smoke free policy.

In this study, the performance of fast gas chromatography system was evaluated using VOC standards prepared in both liquid and gaseous phase. When the liquid‐phase VOC standards were analyzed by both direct injection and HS‐SPME method, all the chromatographic separation was completed within 4 minutes. The calibration experiments were conducted further using gaseous standard of BTX. The calibration results derived by direct injection method generally showed good linearities, regardless of phases, while it was not the case for HS‐SPME method. In case of liquid‐phase standard, MDL values for direct injection and HSSPME method were calculated in the range of 0.07~0.19 to 0.63~3.76 ng, respectively. In contrast, MDL values for gaseous standard were 0.27~0.45 and 1.94~6.90, respectively. The reproducibility of our method, when expressed in terms RSE, showed above 5 %. When the sensitivity of different techniques is compared, the calibration slope values of BTX decreased on the order: direct injection of liquid‐phase standard > HSSPME method of liquid‐phase standard > direct injection of gaseous standard > HS‐SPME method of gaseous standard. Although fast GC is very efficient to reduce the total running time significantly, extended studies are desirable to improve its reproducibility.

In this study, we attempted to estimate the association between asthma oriented by indoor air sources and personal exposure by comparing the case (asthma-patient) and control (non-asthma-patient) groups. We selected 27 participants who showed positive response on lung function and methacholin provocation test. We performed environmental survey with 15 and 10 cases during May and June 2007, respectively. There was no significant difference between the case and control groups in the level of formaldehyde and TBC (Total Bacterial Count). In the dust allergen test, the case concentration was higher than the control's, without signifiant difference. In the personal exposure assessment of VOCs using OVM (Organic Vapor Monitor) badge, the case concentrations of Benzene, Toluene, and Ethylbenzene were higher than the control's, but there was no significant difference. The personal exposure of Xylene case study was significantly higher than the control's