• 한국태양에너지학회 논문집
• /
• 제26권3호
• /
• pp.99-110
• /
• 2006

This study focused on the emission rate of the construction materials. The method of study is as follows. First, validation of small chamber method to determine emission rate of construction material was performed by CFD simulation. For the result of this study, uniform air velocity in small chamber was founded, and small chamber as a test material for emission rate was validated. Second, the construction materials were categorized by their feature and the emission rate of volatile organic compound was determined. Totally, VOCs emission rate of 49 materials were determined.

• KIEAE Journal
• /
• 제7권5호
• /
• pp.53-58
• /
• 2007

In order to predict the indoor air pollutant, the VOCs emission rate is used through small chamber in the design process. However, the small chamber method has limitations as the convective mass transfer coefficient, the most important factor when predicting VOCs contamination of indoor air, is different between the small chamber result and the measured data in the actual building. Furthermore, the existing studies which analyzed mass transfer coefficient in the small chamber were directed on the small chambers developed at the time and FLEC(Field and Laboratory Emission Cell), thus, are different from the current small chamber which has been changed with improvements. The purpose of this study is to determine the emission rate of pollutant in multi-layered building materials, and predict the indoor pollutant concentration through the CFD(Computational of Fluid Dynamics) and CRIAQ2 based on the mass transfer coefficient on singled-layered building material by using the current small chamber widely used in Korea. Futhermore, this study used the new convective mass transfer coefficient(hm') which indicates the existing convective mass transfer coefficient(hm) including VOC partition coefficient(k). Also, formaldehyde was selected as target pollutant.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2006년도 하계학술발표대회 논문집
• /
• pp.277-282
• /
• 2006

In order to predict the indoor air pollutant, the VOCs emission rate is used through small chamber in the design process. However, the small chamber method has limitations as the convective mass transfer coefficient, the most important factor when predicting VOCs contamination of indoor air, is different between the small chamber result and the measured data in the actual building. Furthermore, the existing studies which analyzed mass transfer coefficient in the small chamber were directed on the small chambers developed at the time and FLEC(Field and Laboratory Emission Cell), thus, are different from the current small chamber which has been changed with improvements. The purpose of this study is to determine the emission rate of pollutant in double-layered building materials through the CFD(Computational of Fluid Dynamics) and Numerical analysis based on the mass transfer coefficient on singled-layered building material by using the current small chamber widely used in Korea. Futhermore, this study used the new convective mass transfer coefficient($h_m'$) which indicates the existing convective mass transfer coefficient($h_m$) including VOC partition coefficient(k). Also, formaldehyde was selected as target pollutant.

• 한국철도학회논문집
• /
• 제14권1호
• /
• pp.19-23
• /
• 2011

고속철도 차량의 고속화, 경량화와 더불어 승객의 실내 소음을 줄이기 위한 많은 연구가 진행되고 있다. 고속철도 차량의 실내 소음을 줄이는 방법으로 차량 구조물의 차음 성능을 향상시키는 연구가 중요시 되고 있으나 투과손실 연구는 많은 경제적 비용이 요구된다. 따라서 본 연구에서는 소형 잔향실을 이용하여 고속철도 차량의 투과손실을 측정할 수 있는 방법을 연구 하였다. 연구 결과 소형 잔향실을 이용한 차음성능 연구가 대형 잔향공간을 이용한 투과손실 결과 대비 신뢰성 있는 결과를 도출 하였다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 추계학술대회 논문집
• /
• pp.92-95
• /
• 2011

The walls of modern train cars are required to have higher transmission loss since modern train have had high speed and light weight. The method based on Reverberation Chamber like KS F 2808 could be used to measure transmission loss. However, this method has difficulty in that constrained Standard of it requires extremely large facilities. Recently, the method based on Scale Reverberation Chamber is used as an alternative to Reverberation Chamber. The method of Scale Reverberation Chamber is known to be small and economical but it provides standing wave that directly influences measurement error. Therefore, this research is focus on predicting standing waves based on method of FFM and reducing measurement error by changing shape of chamber.

• 분석과학
• /
• 제18권4호
• /
• pp.344-354
• /
• 2005

최근 들어 실내공기질 악화의 주 오염원인 건축자재에 대한 관심이 고조되면서 건축자재 오염물질 방출시험 자료 구축이 중요하게 됨에 따라, 신뢰성 있는 자료 확보를 위해 건축자재 방출시험 정도 관리에 대한 필요성이 대두되었다. 이에 본 연구는 건축자재 방출시험 성능에 대한 정도관리를 위해 총 휘발성 유기화합물과 포름알데히드에 대하여 기기분석 재현성, 회수율, 검출한계, 중복 및 반복채취 재현성, 파과용량 평가 등을 실시하였다. 기기분석 및 시료채취에 대한 재현성은 20~30% 이내의 양호한 결과를 보였으며, 회수율은 80% 이상으로 나타났으며, 파과 역시 일어나지 않아 소형챔버법에 의한 성능은 전반적으로 만족할 만한 수준을 보였다. 따라서, 소형챔버를 이용한 건축자재 오염물질 방출시험방법은 신뢰성있는 자료를 제공해 줄 수 있을 것으로 판단된다.

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

• 한국지반공학회지:지반
• /
• 제11권2호
• /
• pp.19-28
• /
• 1995

소형 압력 토조(small pressure chamber)를 이용하여 포화된 사질토에 타입된 폐단 강관 말뚝의 인발거동 특성을 연구하였다. 소형 압력 토조 시험에서는 인발 하중이 인발변위와 함께 증가하다가 급작스러운 미끄러짐 변위가 발생되는 현상이 2-3회 반복되다가 완전 인발파괴에 이르게 되는데, 이때 첫번째 미끄러짐 변위가 발생하는 하중의 크기를 극한 인발 지지력으로 정의할 수 있다. 또한, 소형 압력 토조 시험에서는 미세한 시험 조건에 의해서도 극한 인발 지지력의 크기가 50% 이상의 오차를 나타낼 수도 있으므로 모형 지반을 형성할 때마다 인발 재하 시험에 의하여 극한 인발 지지력을 결정하여 사용하는 것이 좋을 것으로 판단되며, 이때 1차 인발 시험에 의해 교란된 지반의 상태는 모형 말뚝의 크기에 적합한 타격에너지를 가해주어 회복시킬 수 있다.

• 한국자동차공학회논문집
• /
• 제5권2호
• /
• pp.162-172
• /
• 1997

We investigated passby noise measurement method in a small-sized semi-anechoic chamber satisfying the American based SAE J1470 Recommended Practice to facilitate the measurements. We have tired two passby noise prediction methods. One is line array microphone method in which the free space sound field is decomposed into its eigenfunctions in the spherical coordinates and rearranged according to the order of the spherical Hankel function. However, due to the characteristics of the spherical Hankel function, it is impossible to distinguish the function's characteristics according to the order in farfield. Consequently it can be applied in the transient region of the nearfield and the farfield. The other method is nearfield acoustic holography(NAH). Although measuring hologram for the several operational engine speeds by conventional scanning method is time-consuming work, we can greatly reduce the measuring time by selecting the appropriate engine speed through preexperimental knowledge. To verify this method we experimented with the outdoor passby noise measurements and the passby noise prediction in the small-sized semi-anechoic chamber for the identical passenger vehicle and obtained reasonable and acceptable results.

• Journal of the Korean Wood Science and Technology
• /
• 제36권2호
• /
• pp.46-55
• /
• 2008

This study assesses the formaldehyde and TVOC emissions from bio-composites with attached fancy veneer manufactured using wood flour and polypropylene (PP) measured using the Field and Laboratory Emission Cell (FLEC) method and 20 L small chamber method. To determine and compare the effects of the adhesive, samples were prepared with different manufacturing methods. In the FLEC result, the formaldehyde emission level of the bio-composites with attached veneer by hot-press was the lowest than pure bio-composite and bio-composite attached veneer using adhesive. The TVOC emission levels are similar to the formaldehyde emission. The TVOC emission level is very low in all of the samples except fancy veneer that is attached with bio-composites using adhesive. The TVOC emission varies depending on how attaching fancy veneer. The results of the 20 L small chamber method were very similar to those obtained with the FLEC, but the correlation was not perfect. However, the FLEC method requires a shorter time than the 20 L small chamber method to measure the formaldehyde and TVOC emissions. The internal bonding strength exceeded the minimum value of $0.4N/mm^2$ specified by the KS standard. All of the bio-composites with attached veneer satisfied the KS standard.