Numerical study of the influences of different patterns of the building and green space on micro-scale outdoor thermal comfort and indoor natural ventilation

2014 ◽  
Vol 7 (5) ◽  
pp. 525-536 ◽  
Author(s):  
Bo Hong ◽  
Borong Lin
Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.


2020 ◽  
Author(s):  
Sabrina Erlwein ◽  
Stephan Pauleit

<p>Urban green and blue spaces such as water bodies, parks and street trees reduce outdoor temperatures and energy consumption of buildings through evaporative cooling and shading and are thus promoted as nature based solutions to enhance climate resilience. However, in growing cities, supply of urban green space often conflicts with increasing housing demand, resulting in dense neighbourhoods with lack of green. Therefore, the transdisciplinary project “Future green city” seeks to identify possibilities for balancing population growth and increasing living space demand with the development of nature-based solutions for climate change adaptation. In a transdisciplinary approach with the City of Munich, living labs are used to investigate how nature-based solutions can be integrated into spatial planning processes.</p><p>For the case of an urban redevelopment site with row buildings and a vast amount of greenery, eight densification scenarios were elaborated with city planners to derive planning guidelines for the further development of the area. The scenarios consider the effects of densification with additional floors and new buildings, the use of new building materials and energy efficiency standards, the construction of underground car parks and consequently a loss of green space to varying degrees. We are particularly interested in the interplay of densification and availability of green and its impact on indoor and outdoor thermal comfort, energy efficiency of buildings and their life cycle based emission balance. Microclimate modelling is employed to quantify and evaluate the impacts of densification on outdoor thermal conditions during heat days and the benefits of urban green in reducing heat stress.</p><p>First modelling results show that additional floors have less impact on human thermal comfort than loss of green space caused by the provision of required parking space. Though underground car parking avoids surface soil sealing, it leads to the removal of existing urban green and excludes the planting of large trees. Informal instruments such as mobility concepts can reduce space consumption by car parking. Moreover, urban redevelopment also bears the potential to increase climate resilience of the stock by targeted greening strategies. The potential is greater, the earlier climate change adaptation is considered as a topic in planning processes. Modelling helps to explore strength and weaknesses of different alternatives in early design stages.</p>


2014 ◽  
Vol 919-921 ◽  
pp. 1677-1680
Author(s):  
Choul Woong Kwon ◽  
Sung Woo Shin

Several complex thermal indices (e.g. PMV and PET) were developed in the last decades to describe the quantify the thermal environment of humans and the energy fluxes between body and environment. Compared to open spaces the complex surface structure of urban areas creates an environment with special microclimatic characteristics, which have a dominant effect on the energy balance of the human body. In this study, outdoor thermal comfort conditions are examined through numerical model with different transparency ratios in canopy. The intensity of radiation fluxes is dependent on several factors, such as orientation, size and transparency of canopy. Special emphasis is given to the human-biometeorological assessment of the microclimate of building element (canopy) through the application of the thermal index PET (Physiological Equivalent Temperature). The analysis is carried out by the utilization of Ecotect and RayMan software.


2019 ◽  
Vol 11 (23) ◽  
pp. 6654 ◽  
Author(s):  
Choul Woong Kwon ◽  
Kang Jun Lee ◽  
Soolyeon Cho

This study analyzed the environmental role of a flexible canopy as a microclimate modifier in balancing indoor energy demands and outdoor thermal comfort. Flexible building elements are often installed in traditional buildings, depending on the local climate in southern Europe. The architectural performance of a canopy was analyzed using several environmental software packages (Ecotect, Rayman, WinAir, DaySim, and EDSL TAS). Coupling methods were applied to determine the environmental influence of the attached building element, a canopy with fixed and operable panes in different orientations and locations. The results showed that the flexible canopy played a crucial role in reducing indoor energy demands (heating and electricity for lighting) and increasing outdoor thermal comfort under the canopy area. Outdoor thermally comfortable conditions ranging between 13 and 29 °C in the canopy space could be enhanced by 56.3% over the entire year by manipulating a flexible canopy, compared with a fixed canopy with 90% transparency in London. The flexible canopy with higher transparency helped increase outdoor thermal comfort in Glasgow, while one with lower transparency showed better performance during summer in London. The findings of this research will help broaden the range of architectural elements used in buildings.


2019 ◽  
Vol 41 (4) ◽  
pp. 466-479
Author(s):  
S Subhashini ◽  
K Thirumaran

This paper attempts to investigate the potential of courtyards in optimizing natural ventilation and improving comfort levels in the learning spaces of a naturally ventilated educational institution with courtyards in the warm-humid climatic region of Madurai. Field measurements and experimental studies were carried out to predict the indoor and outdoor environmental conditions. The numerical study was carried out using computational fluid dynamics-based simulations using Ansys Fluent as the solver. The main aim of the simulation is to understand the airflow pattern and air velocity fields inside the classrooms surrounding the courtyards for different wind directions. The computational fluid dynamics results were validated by comparing it with the experimental results obtained in the current study and numerical results from other studies. The major findings of the current study suggest that courtyards with an aspect ratio of 1:2, orientations of openings at an angle of 0–20° to the predominant wind directions and the overall percentage of openings between 15 and 30% in buildings in Madurai region can enhance natural ventilation and thus improve thermal comfort of the occupants. Practical application: Naturally ventilated buildings in warm-humid climates have difficulty in providing thermal comfort to the occupants. CFD tools have been used to predict the ventilation performance of a naturally ventilated educational building with courtyards. The CFD results were helpful in identifying the implication of building design on the indoor air flow pattern. The recommendations given in this paper are applicable to any building type which relies on natural ventilation for thermal comfort provided they have similar building configurations, boundary conditions and weather conditions. The study is intended to help architects and building designers in the effective design of naturally ventilated buildings with respect to its climatic conditions.


Arsitektura ◽  
2018 ◽  
Vol 16 (2) ◽  
pp. 155
Author(s):  
Juliana Bekti Susilaning Budi ◽  
Khairunnisa Fifthariski ◽  
Sri Yuliani ◽  
Wiwik Setyaningsih

<p class="Abstract"><em>The natural air conditioning in the medical school building hall of the Faculty of Medicine, Universitas Sebelas Maret needs to be optimized in order to achieve maximum thermal comfort. Optimal natural stability with the support of green space within a building can increase the level of comfort that supports user activity. The purpose of the research is to optimize the natural system applied in the building that is on the void located in the middle of the building by providing green space placed on the hall of the building so as to provide maximum thermal comfort on the user building according to principles in architectural design . This research used qualitative method based on literartur study, field observation and interview result with user of doctor building of Faculty of Medicine, Sebelas Maret University. The expected result from the provision of green space in the hall space of the building is the optimal natural innate in the building so that the building users feel comfortable in the move.</em></p>


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