• 국제초고층학회논문집
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• 제12권2호
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• pp.129-136
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• 2023

Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

• KIEAE Journal
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• 제15권4호
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• pp.29-35
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• 2015

Purpose: Double skin facade is a representative advantageous passive technology of building skin in the aspect of energy saving and environment improvement, reduces heat loss with buffer space in winter season and enhances indoor air and comfort of residents by activating natural ventilation in mid-season. However, in summer season, temperature increase in the intermediate space due to solar energy from exterior transparent skin could be a potential problem; also, relatively weak buoyancy of air caused by low density difference between double-skin facade could increase cooling load as air of intermediate space in high temperature hangs. However, proof data is insufficient to objectify such phenomenon. Method: In this study, researchers surveyed air temperature of intermediate space and airflow and diagnosed its cause targeting on applied multistory facade in the building which gives thermal uncomfort to residents. Also, the researchers produced Solar-air heat transfer coefficient meter, measured thermal boundary condition of double-skin facade, and presented the result of measurement as an objectified verification material regarding overheating phenomenon in the intermediate space of double-skin facade in summer season. Result: Inefficient condition was verified that total heat increases and overheating due to insufficient natural ventilation in multistory facade. In addition, logic behind preceding research was objectified and verified regarding high temperature phenomenon in the intermediate space which could increase cooling load in summer season.

• 설비공학논문집
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• 제23권2호
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• pp.153-163
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• 2011

Energy efficiency and indoor air quality have become main issue to develop healthy and sustainable building in these days. As an effort to reduce the energy consumption in multi-residential building, many attempts as like passive design strategies and renewable energy as well as active control method are tried. However, underground parking lot in multi-residential building seldom adopt the sustainable strategies and only mechanical system is installed as usual. Moreover, the mechanical system installed in underground parking lot is rarely operated due to the electric demand for operation after completion. In this study, as an energy efficient measure, natural ventilation system using stack effect as a driving force for underground parking lot will be proposed and the performance of the suggested system will be analyzed by simulation method.

• 한국태양에너지학회 논문집
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• 제26권4호
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• pp.101-107
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• 2006

The Purpose of this study is to provide the basic data for energy conservation strategies of the multipurpose greenhouse which is appropriate to Jeju environmental circumstance. In this study, climatic analysis, field works, literature reviews and building load calculations were performed to identify solutions to design needs. As conceptual design strategies, various energy conservation strategies such as passive solar design, natural ventilation and high performance glazing system were examined and applied to design alternatives.

• 교육시설
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• 제9권4호
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• pp.95-102
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• 2002

The purpose of this study is to renovate a closed school to a artist studio complex applying sustainable principles and methods. Through the case study, the principle and methods of sustainable renovation is investigated and following strategies are extracted as a frame of renovation. First, atrium space with thermal mass using existing wall is proposed as a public gathering space. Second, light shelves for effective lighting and shading device for protecting and allowing sun light is proposed to renovate existing classroom. Third, double skin system is proposed with reflection pool to activate heating and ventilation for passive solar as well as passive cooling. Finally, simulation programs such as energy-10 and Form-Z is used to confirm the validity of the sustainable design.

• 방사성폐기물학회지
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• 제3권3호
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• pp.183-192
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• 2005

자연환기는 처분장의 작업 환경 및 위생, 부유 방사성 핵종의 노출 등과 같은 안전문제에 있어 자연환기 자체만으로는 기계적 강제 환기에 비해서 덜 효과적이지만 처분장 내의 수분제거, 작업 환경 조성과 관련하여 라돈 (Rn) 가스의 희석과 같은 향후 처분장의 장기적 환경을 위해서는 중요한 역할을 할 수 있고, 환풍기와 같은 환기 설비를 이용해야하는 기계환기에 비해 경제적으로 매우 효과적 일수 있다. 본 논문에서는 지하 처분장의 건설 및 운영 기간동안 자연환경 조건에 따라 처분장에 스스로 생기는 자연 환기의 타당성에 대하여 기술하였다. 자연 동굴을 통한 자연환기 유사에 의해 밝혀진 증거들과, 수직갱을 갖는 산악 도로터널에서의 자연 환기 측정, 그리고 주어진 자연환기 압력에 의한 공기 발생량 계산 등을 통해서 자연 환기는 한국형 지하 방사성 폐기물 처분장에 잠재적으로 매우 유익함을 알 수 있다. 효과적으로 유도된 자연 환기는 방사성 폐기물 처분장 내에 발생하는 열과 습도, 그리고 라돈 가스를 제어하기에 경제적으로 좋은 방법이 될 수 있다. 자연환기를 통해 처분장의 전반적 열적 특성은 개선될 수 있고, 수분으로 포화된 공기는 효과적으로 건조되고 그 건조상태 유지 기간은 확장 될 수 있을 것이다.

• 한국환경보건학회지
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• 제33권4호
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• pp.255-263
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• 2007

Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time indoors. The purposes of this study were to evaluate the alternative method for improvement of indoor air quality in house after coating titanium dioxide ($TiO_2$) photocatalyst for interior part of the house using nitrogen dioxide ($NO_2$) multiple measurements. To evaluate the alternative method in indoor environment, daily indoor and outdoor $NO_2$ concentrations of an apartment and a detached house were daily measured for consecutive 21 days in winter and summer, respectively, Another daily 21 measurements were carried out after $TiO_2$ coating on wall paper of interior part in houses. All $NO_2$ concentrations were measured by passive filter badges. Indoor air quality models using mass balance are useful tool to quantify the relationship between indoor air pollution levels, ambient concentrations, and explanatory variables. Using a mass balance model and linear regression analysis, penetration factor (ventilation rate divided by sum of ventilation rate and decay rate) and source strength factor (emission rate divided by sum of ventilation rate and decay rate) were calculated. Subsequently, the decay constants were estimated. In this study. magnitude of improvement of indoor air quality could be evaluated by decay constant.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.751-756
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• 2009

In the perspective of saving energy in buildings, the high performance of insulation and air tightness for improving the heating and the cooling efficiency, has brought economically positive effects. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and is also very harmful to the residents, because they spend over 90% of their time indoors. Therefore, the ventilation is important to keep the indoor environment clean and it can also save the energy consumption. In this study, a HEPA type nano ceramic filter is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. The double layer filter, which has $30{\mu}m$ in diameter at the conditions of 10wt% of concentration and 3kV/cm of the electric intensity, is produced by electrospinning. The filtration coating technology is confirmed in the solution with $SiO_2$ nano particles using polymer nano fibers. Also double layer filters are coated with $SiO_2$ nano particles and finally the porous construction materials are made by sintering in the electric furnace at $200{\sim}1400^{\circ}C$. The efficiency is measured 96.67% at the particle size of $0.31{\mu}m$, which is slightly lower than HEPA filter. However the efficiency is turned out to be sufficient.

• 설비공학논문집
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• 제20권4호
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• pp.274-279
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• 2008

In the perspective of saving energy in buildings, high performance of insulation and air tightness for improving the heating and the cooling efficiency has brought the positive effect in an economical view. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and it is also very harmful to residents because they spend over 90% of their time in the indoor area. Therefore, the ventilation is important to keep indoor environment clean and it can also save energy consumption. In this study, a HEPA type breathing wall is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. To make fine porous structures, polymer nano fibers which were made by electro spinning method are used as a precursor. The nano fibers are coated with SiO2 nano particles and finally the HEPA type breathing wall is made by sintering in the electric furnace at $300\sim500^{\circ}C$. The pressure drops of nano ceramic structure are 8.2, 25.5 and 44.9 mmAq at the face velocity of 2.0, 5.9 and 8.8 cm/s, respectively. Also the water vapor permeability is $3.6g/m^2{\cdot}h{\cdot}mmHg$. In this research, the porous nano ceramic structures are obtained and the possibility for the usage of a material for HEPA type breathing wall can be obtained.

• Journal of Preventive Medicine and Public Health
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• 제47권3호
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• pp.169-176
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• 2014

Objectives: This study aimed to evaluate occupational symptoms and chemical exposures of nail salon technicians. Methods: Work-related symptoms of nail salon technicians in Daegu City were surveyed using a researcher-administered questionnaire, and responses were compared to those of non-exposed office workers as controls. Personal exposure level of airborne volatile organic compounds was also monitored using passive samplers. Results: A total of 159 subjects in 120 salons were interviewed. Average work-shift concentrations of 13 chemicals were measured for 50 workers from 30 salons using personal passive samplers. The most frequently reported respiratory or neurologic symptoms by nail shop technicians compared to controls were nose irritation (odds ratio [OR], 54.0; confidence interval [CI], 21.6 to 134.8), followed by headache (OR, 9.3; CI, 4.7 to 18), and throat irritation (OR, 4.3; CI, 2.2 to 8.5). For eyes and skin, 92% of respondents complained eye irritation (OR, 13.1; CI, 5.7 to 30.1). In musculoskeletal symptoms, workers reported pain or discomfort in shoulders (OR, 20.3; CI, 7.7 to 54) and neck (OR, 19.7; CI, 8.9 to 43.6). From personal measurements, the proportion of exceeding the Korean Occupational Exposure Limit was the highest for acetone with 64%, followed by toluene (50%), butyl acetate (46%), and methyl methacrylate (12%). However, the service was being provided without a proper ventilation system in most surveyed shops. Conclusions: Based on these findings, it is warranted to have appropriate local exhaust ventilation place to ensure adequate health protection of nail shop technicians as well as customers. At the same time, greater policy interests are warranted in nail care business to protect health of both workers and customers.