• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.78-85
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• 2011

In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

• KIEAE Journal
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• v.5 no.4
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• pp.3-8
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• 2005

The objective of this study is to examine the impact of the Phytofiltration system on the improvement of indoor air quality. Measurement was performed in a full-scale mock up model to examine the purification efficiency of air by plants. Seven species of plants, which were recommended by NASA, were used in measurements. Two species of plants that showed outstanding purifying effects were chosen for further measurements. The measurements were performed according to the positions and amounts of plants. Thermal environment, the concentration of Toluene and Formaldehyde were monitored. Ficus Benjamiana and Aglaonema brevispathum were excellent in diluting the concentration of contaminants. The effect of diluting concentration became better as the amount of plants increased. The reducing effect was the best when the plants were placed near window.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.5
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• pp.496-504
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• 2005

Heat recovery ventilators (HRV) are developed in order to satisfy both energy conservation and the improvement of indoor air quality as an alternative for current natural ventilation systems and local mechanical ventilation systems in kitchens and bathrooms. However, the performance of HRV system and the consequent effect on heating and cooling energy saving have not been sufficiently validated quantitatively in case of the application of HRVs in real residences. In this study, field measurement and computer simulation were conducted in both summer and winter period to assess the performance and validate energy conservation effect of HRVs. Under the Korea weather condition, average total heat recovery efficiency was $27\%$ in summer and $46\%$ in winter. According to the field measurement, HRV system can save the energy by $10\%$ in summer and 15$\%$ in winter. Furthermore, according to the simulation assessment, HRV system can save the energy by $17\%$ in summer and $17\%$ in winter.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.723-735
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• 2018

In this study, to investigate an optimal configuration method for the modeling system, we performed an optimization experiment by controlling the types of compilers and libraries, and the number of CPU cores because it was important to provide reliable model data very quickly for the national air quality forecast. We were made up the optimization experiment of twelve according to compilers (PGI and Intel), MPIs (mvapich-2.0, mvapich-2.2, and mpich-3.2) and NetCDF (NetCDF-3.6.3 and NetCDF-4.1.3) and performed wall clock time measurement for the WRF and CMAQ models based on the built computing resources. In the result of the experiment according to the compiler and library type, the performance of the WRF (30 min 30 s) and CMAQ (47 min 22 s) was best when the combination of Intel complier, mavapich-2.0, and NetCDF-3.6.3 was applied. Additionally, in a result of optimization by the number of CPU cores, the WRF model was best performed with 140 cores (five calculation servers), and the CMAQ model with 120 cores (five calculation servers). While the WRF model demonstrated obvious differences depending on the number of CPU cores rather than the types of compilers and libraries, CMAQ model demonstrated the biggest differences on the combination of compilers and libraries.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.5
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• pp.468-476
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• 2005

The purpose of this study is to investigate actual air quality in newly-constructed multi-family houses and to improve Indoor Air Quality (IAQ). The field measurement was conducted in four different newly-constructed multi-family house complexes in Seoul and one existing multi-family house complex in Kyong-gi province. The result of the measurement shows that indoor concentrations of Formaldehyde and TVOC in newly-constructed multi-family houses are much higher than the foreign standards. To establish a proper process for reducing indoor air pollutants, various experiments have been conducted; application of natural materials, bake-out practice, closure of all openings without ventilation, and use of mechanical ventilation system. The result indicates that three practices (natural materials, bakeout, mechanical ventilation) can reduce the level of indoor air pollutants almost in half during the experiments. However, each practice has its limitation and is insufficient to satisfy IAQ standards. Therefore, the study proposes a proper reduction process of indoor air pollutants which combines four different practices in time sequence.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.6
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• pp.616-625
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• 2017

Measurements using five real-time particle samplers were compared to measurements using three NRM (National Reference Method system) filter-based samplers(Gravimetric method) at Incheon, Korea, between May and August, 2014. The purpose of this study was to suggest the quality assurance/quality control (QA/QC) method of each instrument for use in a real-time continuous particle sampler to measure the mass of airborne particles with an aerodynamic diameter less than $2.5{\mu}m$ ($PM_{2.5}$). Five real-time particle samplers of BAM1020, FH62C_14, TEOM, PM-711 and SPM-613 were evaluated by comparing its measured 23 hr average $PM_{2.5}$ concentrations with those measured with NRM filter-based samplers simultaneously. The parameters(e.g. Inlet heating condition, Slope factor, Film response, Intercept, Background, Span value) of the real-time samplers were optimized respectively by conducting test performance evaluation during 7 days in field sampling. For example, inlet heating temperature of TEOM sampler controls $35{\sim}40^{\circ}C$ to minimize the fluctuation of the real-time measurement data and background value of BAM1020 is the key factor affecting the accuracy of $PM_{2.5}$ mass concentration. We classified the $PM_{2.5}$ concentration according to relative humidity (80%) to identify water absorbed in aerosols by measuring the ${\beta}$-ray samplers(BAM1020, FH62C_14) and TEOM. ${\beta}$-ray samplers were not strongly affected by relative humidity that the difference of the average $PM_{2.5}$ concentration was about 5%. On the other hand, The TEOM sampler overestimated $PM_{2.5}$ mass concentration about 15% at low relative humidity (<80%).

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.171-178
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• 2019

In this paper, we proposed a plan for a indoor air quality management in elderly care hospital by measuring the indoor air quality level of elderly care hospital and conducting a survey the workers' awareness of indoor air quality. The measurement items were Temperature, Humidity, CO2, CO, PM10, VOC and were taken on April 26, 2019. The survey found that the lower the satisfaction level with indoor air quality, the better outdoor air quality and odor items were analyzed to be the lowest among the indoor environmental factors. When the satisfaction level of indoor air quality is high, the satisfaction level of indoor environment factor is high. The result of the multiple response analysis was "lack of ventilation" and the regression analysis was the lower the "relevance of indoor air quality" category. To provide the best indoor air quality environment for elderly care hospital workers the installation of additional ventilation equipment to remove odors, the increase in the number of natural ventilation and the designation of regular ventilation personnel will be necessary. By establishing such a plan, it is possible to provide indoor air quality environment to provide the best services for elderly care hospital workers.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.4
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• pp.289-303
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• 2009

The chemical and meteorological effects on the concentration variations of ozone ($O_3$) were evaluated based on the intensive air quality measurement (5 pollutants and aromatic volatile organic compounds (AVOCs)) in and out-side an urban valley during spring and summer of 2006. The 5 pollutants measured in the study area include $O_3$, $NO_2$, NO, $PM_{10}$, and CO; the AVOCs include benzene (BEN), toluene (TOL), ethylbenzene (EB), m,p-xylene (MPX), and o-xylene (OX). For the purpose of this study, study areas were classified into two categories: valley area (VA) with a semi-closed topography covering a number of industrial complex, public building, and mountains and non-valley area (NVA) surrounding the suburban and residential areas. In general, the mean concentration levels of most pollutants (except for $PM_{10}$) in the VA were higher than those in the NVA. It was found that the average $O_3$ increase in the VA during spring might result from the combined effects such as the photochemical production from diverse anthropogenic sources and the $O_3$ accumulation due to geographical features (e.g., the semi-closed topography) and wind conditions (e.g., a low wind speed). In addition, the nocturnal $O_3$ increase in the VA during spring was primarily caused by local wind conditions (e.g., mountain and valley winds) with the low wind speed (approximately $1{\sim}2\;m\;s^{-1}$). On the other hand, the $O_3$ difference between the two areas during summer might be because of the photo-chemical production with the $O_3$ precursors (especially the AVOCs) rather than the contribution of wind conditions.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.215-231
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• 2018

It was analyzed to identify the cause of $PM_{2.5}$ concentration changes for the fall in 2016 and 2017 in South Korea using ground measurement data such as meterological variables and $PM_{2.5}$, AOD from GOCI satellite, and WRF-CMAQ modeling system. The result of ground measurement data showed that the $PM_{2.5}$ concentrations for the fall in 2017 decreased by 12.3% ($3.0{\mu}g/m^3$) compared to that of 2016. The difference of $PM_{2.5}$ concentrations between 2016 and 2017 mainly occurred for 11 Oct. - 20 Oct. (CASE1) and 15 Nov. - 19 Nov. (CASE2) when weather conditions were difficult to long-range transport from foreign regions and favored atmospheric ventilation in 2017 compared to 2016. Simulated $PM_{2.5}$ concentrations in 2017 decreased by 64.0% ($23.1{\mu}g/m^3$) and 35.7% ($12.2{\mu}g/m^3$) during CASE1 and CASE2, respectively. These results corresponded to the changes in observed $PM_{2.5}$ concentrations such as 53.6% for CASE1 and 47.8% for CASE2. It is implied that the changes in weather conditions affected significantly the $PM_{2.5}$ concentrations for the fall between 2016 and 2017. The contributions to decreases in $PM_{2.5}$ concentrations was assessed as 52.8% by long-range transport from foreign regions and 47.2% by atmospheric ventilation effects in domestic regions during CASE1, whereas their decreases during CASE2 were affected by 66.4% from foreign regions and 33.6% in domestic regions.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.21-28
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• 2010

Air pollution monitoring has attracted a lot of interests because it affects directly to the human life quality. The most of the current air pollution monitoring stations use the expensive and bulky instruments and are only installed in the specific area. Therefore, it is difficult to install them to as many places as people need. In this work, we constructed a low price and small size Radio Frequency(RF) sensor system to solve this problem. This system also had the measurement range similar to the ones used in the air pollution forecast systems. This system had the sensor unit to measure the air quality, the central processing unit for air quality data acquisition, the power unit to supply the power to every units, and the RF unit for the wireless transmission and reception of the data. This system was easy to install in the field. We also added a GPS unit to track the position of the RF-sensor in real time by wireless communication. For the various measurements of the air pollution, we used CO, $O_3$, $NO_2$ sensors as gas sensors and also installed a dust sensor.