• 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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• 제7권6호
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• pp.9-15
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• 2007

Ventilation of buildings provide occupants with comfort and plays a very informant role in supplying indoor ventilation requirement. Also, natural ventilation is more comfortable than forced ventilation taking account of mental comfort. Especially factors, airflow velocity and direction etc., should be reflected in establishment of comfortable indoor environment because indoor airflow can directly affect comfort of occupants. However, a device which enables indoor air movement to be analyzed has not existed until now. Hence, it has mostly depended on simulation results of fluid analysis but the results often differ far from reality. PST(Particle-Streak-Tracking) System, an alternative to improve this problem, is currently applied to natural ventilation in building, air conditioning, and airflow analysis in the inside of a plane etc. This study closely examine the property and strength and weakness of PST that is first introduced into KICT and then evaluate applicable possibility.

• 한국환경과학회지
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• 제17권9호
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• pp.993-1003
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• 2008

Interior space in most buildings is divided into several zones. The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. An integrated multizone model to predict these environmental factors simultaneously was developed. Also, a computer program for this model was written by the language of VISUAL BASIC. The proposed model was applied to a apartment with five rooms that had been tested by Chung. Comparison of predicted results by this study with measured results by Chung showed that their variations were within 14% for airflow rates, 1% for temperatures, 12% for humidities, and 5% for concentrations. It was seen that the opening operation schedule of building has a significant effect on the air moisture md contaminant removal. Thus, this model may be available for predicting the indoor air environment and may be contributed to design the ventilation plan for controling of indoor air quality.

• 설비공학논문집
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• 제28권2호
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• pp.55-62
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• 2016

The air flows in building caused by thermal buoyancy, known as the stack effect, have a pronounced influence on both the indoor environment (thermal environment, noise, draught and contaminant diffusion) and energy needs in high-rise buildings. Prior studies for airflow in high-rise buildings were focused on the degree of stack effect and countermeasures. The wind pressure was neglected during the calculation of the indoor airflow in high-rise buildings to clarify the effect of thermal buoyancy in previous studies. However, wind is an important driving force of indoor airflows in buildings with the stack effect. In this study, the effect of wind pressure on indoor airflow in high-rise building when the stack effect is dominant in winter was analyzed. In this paper, methods that involved considering the wind pressure in airflow network simulation were analyzed.

• 설비공학논문집
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• 제12권1호
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• pp.40-49
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• 2000

The flow and heat transfer characteristics of the exhaust airflow window system were studied numerically by a finite volume method. Attention was paid to see the decrease in indoor cooling load. The exhaust air flow rate, solar energy power and aspect ratio of window were considered as main variables. From the result of the comparison between the exhaust airflow window and the enclosed window, the indoor heat gain was reduced remarkably by 76%. It is also suggested that in the design of the exhaust airflow window optimum values of aspect ratio, H/W and exhaust air flow rate, Re were about 0.05 and 600, respectively.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.993-998
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• 2006

High-rise apartments have a problem using natural ventilation because of the strong outdoor wind velocity. Conventional high-rise apartments have adopted mechanical ventilation systems to maintain the indoor air quality. However, it leads to the overuse of electricity and the sick house syndrome. Double-skin facade is the alternative for the high-rise building to use natural ventilation and this study is focused on the performance of the box-window, which is a kind of double-skin facades. Indoor wind velocity and HCHO concentrations are analyzed with three types of box-windows: the diagonal type, parallel type and perpendicular type. The airflow is simulated by computational fluid dynamics program. Box-windows reduce the maximum value of indoor wind velocity about 50% compared with the single window and the HCHO concentrations do not have the big difference. Box-windows could be the alternative to enhance the use of the natural ventilation and indoor air quality of the high-rise apartment.

• 설비공학논문집
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• 제19권4호
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• pp.299-306
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• 2007

Recently, the numerical analysis using person shape model for CFD (Computational Fluid Dynamic) has been researched widely for the thermal comfort and inhaled air quality of human body in the indoor environments. The purpose of this research is to examine the characteristic of airflow and thermal environment around human body by the experiment of displacement ventilation that assumes the indoor environment of natural convection. In this study, thermal manikin was used instead of real human body. The Airflow characteristic around human body was measured in precision by PIV (Particle Image Velocimetry). This experimental result will be used as data for CFD benchmark test using person shape model.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.21-26
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• 2005

We performed the numerical analysis on the characteristics of indoor air quality and local supply index with a variation of supply · exhaust airflow rate. We analyzed the local supply index and carbon dioxide concentration at the room and breathing zone with respect to the variation of the supply · exhaust airflow rate. From the numerical results, we found that local supply index was affected but carbon dioxide concentration was hardly affected by the variation of the airflow rate in the room. And we also knew that carbon dioxide concentration was raised in despite of the increment of the supply airflow rate in the breathing zone. After this study it is necessary to analyze the local exhaust index when we evaluate the state of the ventilation in the room.

• 환경영향평가
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• 제31권5호
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• pp.334-342
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• 2022

대기환경보전법이 강화되면서 야외저탄장을 옥내화 함으로써 외부로 날리는 비산먼지는 감소했지만, 저탄장에서 발생하는 석탄 비산먼지와 유해물질들을 단순히 격리함으로서 이러한 물질들이 내부에 축적되어 또 다른 문제를 야기할 수 있다. 본 연구는 이를 해결하기 위해 운영 중인 옥내 저탄장을 선정하여 내부 기류 흐름 양상과 환기량을 분석하였다. 옥내저탄장 내부 기류는 전반적으로 지형적으로 산 쪽에 접한 남서쪽으로 이동하는 경향을 보였다. 그리고 바다와 접한 북쪽 루버에서는 해풍에 의한 기류가 유입되고 있었다. 옥내저탄장 내부로 유입되는 총 유량은 918,691m³/h, 시간당 자연환기 횟수는 0.6회로 나타났다. 연구 결과를 바탕으로 내부 기류가 집중되는 위치에 강제 환기장치를 설치하는 것을 제안한다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.517-522
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• 2008

Ventilation rate and filter were selected to simultaneously satisfy indoor air quality and minimize energy consumption in residential housing. The concentrations of indoor particles were calculated using an adapted mass balance model for various ventilation airflow rates. To satisfy the guidelines for indoor concentrations of particles, the minimum ventilation rates of 1.0/h, 0.6/h and 0.4/h were required for MERV11, MERV13 and MERV14, respectively. And the fan power consumptions induced by ducts, a heat exchanger and a filter were calculated for various ventilation airflow rates. The increase in the ventilation rate caused a dramatic increase in the power consumption, but the filter performance did not have much of an effect on the fan power for ventilation airflow rates lower than 0.4/h. The use of the ventilation filter of MERV 14 was suggested at a ventilation rate of 0.4/h when the fan power consumptions were considered in addition to the indoor concentrations of particles and $CO_2$. The use of the MERV14 filter at a ventilation rate of 0.6/h could be more effective than the additional use of an indoor air cleaner when the residential housing unit was ventilated.