EVALUASI PERFORMA VENTILASI ALAMI PADA DESAIN BUKAAN RUANG KELAS UNIVERSITAS ATMA JAYA YOGYAKARTA

2017 ◽  
Vol 10 (3) ◽  
pp. 149
Author(s):  
Jackobus Ade Prasetya Seputra

Abstract: Education is an important sector of a nation toward better future. Conducive classroom with well designed room ventilation would encourage occupants in implementing effective teaching and learning activities. Research was conducted to figure out classroom performance and optimization of natural ventilation which was occurred in Engineering Faculty of UAJY represented by the classroom number 2406 as case study. Research is focused on classroom ventilation elements by examining window’s dimension, occupant’s adaptive behavior, opening types, and glass type at windward side. This research implements rationalistic method by utilizing computer simulation software DesignBuilder complemented with CFD in order to analyze and deduce information obtained primarily by field measurement and other relevant literatures. Results generated by DesignBuilder show that changes in ventilation area at external windows have significant influence over room’s ventilation performance. CFD (Computational Fluid Dynamics) experiments were conducted by examining opening types shown on room’s vertical section drawing, opening positions, overhangs, and external louvre types. Results show that experiments conducted by replacing the bottom layer of fixed windows with operable windows has significant effect in improving ventilation performance. Variation on overhangs only produce little impact, yet experiments on external louvres prove that the best type is horizontal louvre. Optimization done by studying above variables is capable to increase ventilation performance up to 800% in examined classroom.Keywords: ventilation, optimization, room openings, computer simulationAbstrak: Sektor pendidikan adalah tulang punggung suatu bangsa demi menuju masa depan yang lebih baik. Ruang kelas yang berkualitas dan kondusif dengan perencanaan sistem ventilasi dalam ruang yang baik bagi kegiatan belajar mengajar akan membantu tercapainya tujuan tersebut. Penelitian ini dilakukan untuk mengetahui sejauh mana performa ventilasi alami ruang dengan studi kasus Ruang Kelas 2406 Gedung Fakultas Teknik UAJY dan bagaimana bentuk optimasinya. Penelitian berfokus pada elemen bukaan dengan berbagai dimensi jendela, pengaturan adaptif penghuni, jenis bukaan ventilasi pada jendela, serta jenis kaca jendela pada sisi windward (angin datang). Metode simulasi komputer diperkuat dengan pengukuran lapangan menjadi alat bantu menakar dan mengoptimalisir kebutuhan ventilasi alami melalui berbagai variasi desain bukaan. Hasil studi dengan DesignBuilder memperlihatkan bahwa variabel luasan ventilasi pada jendela (“external window open”) memiliki pengaruh besar terhadap performa ventilasi alami dalam ruang. Studi dengan CFD (Computational Fluid Dynamics) berfokus pada model bukaan ruang, yaitu model bukaan pada potongan vertikal ruang, posisi bukaan, tipe teritisan (“overhang”) serta kerai (“louvre”) eksternal. Eksperimen pada posisi bukaan inlet menunjukkan bahwa perubahan jendela mati menjadi jendela hidup pada lapis bawah menghasilkan performa ventilasi lebih baik. Studi teritisan tidak memiliki pengaruh besar, sedangkan studi kerai membuktikan bahwa jenis kerai terbaik adalah kerai horisontal. Optimasi ini mampu meningkatkan performa ventilasi hingga 800% pada studi kasus.Kata kunci: ventilasi, optimasi, bukaan ruang, simulasi komputer

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ashraf Balabel ◽  
Mohammad Faizan ◽  
Ali Alzaed

Recently, increased attention has been given to the coupling of computational fluid dynamics (CFD) with the fuzzy logic control system for obtaining the optimum prediction of many complex engineering problems. The data provided to the fuzzy system can be obtained from the accurate computational fluid dynamics of such engineering problems. Windcatcher performance to achieve thermal comfort conditions in buildings, especially in hot climate regions, is considered as one such complex problem. Windcatchers can be used as natural ventilation and passive cooling systems in arid and windy regions in Saudi Arabia. Such systems can be considered as the optimum solution for energy-saving and obtaining thermal comfort in residential buildings in such regions. In the present paper, three-dimensional numerical simulations for a newly-developed windcatcher model have been performed using ANSYS FLUENT-14 software. The adopted numerical algorithm is first validated against previous experimental measurements for pressure coefficient distribution. Different turbulence models have been firstly applied in the numerical simulations, namely, standard k-epsilon model (1st and 2nd order), standard Wilcox k-omega model (1st and 2nd order), and SST k-omega model. In order to assess the accuracy of each turbulence model in obtaining the performance of the proposed model of the windcatcher system, it is found that the second order k-epsilon turbulence model gave the best results when compared with the previous experimental measurements. A new windcatcher internal design is proposed to enhance the ventilation performance. The fluid dynamics characteristics of the proposed model are presented, and the ventilation performance of the present model is estimated. The numerical velocity profiles showed good agreement with the experimental measurements for the turbulence model. The obtained results have shown that the second order k-epsilon turbulence can predict the different important parameters of the windcatcher model. Moreover, the coupling algorithm of CFD and the fuzzy system for obtaining the optimum operating parameters of the windcatcher design are described.


2016 ◽  
Vol 25 (8) ◽  
pp. 1226-1247 ◽  
Author(s):  
Ruiqiu Jin ◽  
Jian Hang ◽  
Shanshan Liu ◽  
Jianjian Wei ◽  
Yang Liu ◽  
...  

This study employed two ventilation indexes: local mean age of air and air change rate per hour, to investigate wind-induced natural ventilation of 260 wards of a multi-storey hospital building in suburb of Guangzhou using computational fluid dynamics simulations. Using the surface-grid extrusion technique, high-quality hexahedral grid cells were generated for the coupled outdoor and indoor airflow field. Turbulence was solved by the renormalisation group k-ɛ model validated against experimental data with grid independence studies. Homogeneous tracer gas emission was adopted to predict room age of air. The air change rate of cross ventilation and single-sided ventilation can reach 30–160 h−1 and 0.5–7 h−1, respectively. Due to different locations of room openings on the balconies, natural ventilation of a room can be greatly better than its neighbouring room. The wind-induced cross ventilation highly depends on the distance from the room opening to the stagnation point and on the resulting pressure distribution on the target building surface. Furthermore, it is significantly influenced by the upstream buildings, the bent shape of the target building, and the prevailing wind directions. The coupled computational fluid dynamics methodologies with integrated ventilation indexes are useful for assessing the natural ventilation performance in other complex built environments.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hassam Nasarullah Chaudhry ◽  
John Kaiser Calautit ◽  
Ben Richard Hughes

The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment.


2018 ◽  
Vol 28 (5) ◽  
pp. 677-692 ◽  
Author(s):  
Daniel Risberg ◽  
Mikael Risberg ◽  
Lars Westerlund

There is currently an increasing trend in Europe to build passive houses. In order to reduce the cost of installation, an air-heating system may be an interesting alternative. Heat supplied through ventilation ducts located at the ceiling was studied with computational fluid dynamics technique. The purpose was to illustrate the thermal indoor climate of the building. To validate the performed simulations, measurements were carried out in several rooms of the building. Furthermore, this study investigated if a designed passive house located above the Arctic Circle could fulfil heat requirements for a Swedish passive house standard. Our results show a heat loss factor of 18.8 W/m2 floor area and an annual specific energy use of 67.9 kWh/m2 floor area, would fulfils the criteria. Validation of simulations through measurements shows good agreement with simulations if the thermal inertia of the building was considered. Calculation of heat losses from a building with a backward weighted moving average outdoor temperature produced correct prediction of the heat losses. To describe the indoor thermal climate correctly, the entire volume needs to be considered, not only one point, which normally is obtained with building simulation software. The supply airflow must carefully be considered to fulfil a good indoor climate.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 406 ◽  
Author(s):  
Xiaoyu Ying ◽  
Yanling Wang ◽  
Wenzhe Li ◽  
Ziqiao Liu ◽  
Grace Ding

This paper presents a study of the effects of wind-induced airflow through the urban built layout pattern using statistical analysis. This study investigates the association between typically enclosed office building layout patterns and the wind environment. First of all, this study establishes an ideal site model of 200 m × 200 m and obtains four typical multi-story enclosed office building group layouts, namely the multi-yard parallel opening, the multi-yard returning shape opening, the overall courtyard parallel opening, and the overall courtyard returning shape opening. Then, the natural ventilation performance of different building morphologies is further evaluated via the computational fluid dynamics (CFD) simulation software Phoenics. This study compares wind speed distribution at an outdoor pedestrian height (1.5 m). Finally, the natural ventilation performance corresponding to the four layout forms is obtained, which showed that the outdoor wind environment of the multi-yard type is more comfortable than the overall courtyard type, and the degree of enclosure of the building group is related to the advantages and disadvantages of the outdoor wind environment. The quantitative relevance between building layout and wind environment is examined, according to which the results of an ameliorated layout proposal are presented and assessed by Phoenics. This research could provide a method to create a livable urban wind environment.


Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. P. Huynh

Abstract Windcatcher has been used over centuries for providing natural ventilation using wind power, it is an effective passive method to provide healthy and comfortable indoor environment. The windcatcher’s function is based on the wind and on the stack effect resulting from temperature differences. Generally, it is difficult for wind to change its direction, and enter a room through usual openings, the windcatcher is designed to overcome such problems since they have vertical columns to help channel wind down to the inside of a building. The efficiency of a windcatcher is maximized by applying special forms of opening and exit. The openings depend on the windcatcher’s location and on its cross sectional area and shape such as square, rectangular, hexagonal or circular. In this study the effect of the inlet design is investigated to achieve better air flow and increase the efficiency of windcatchers. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a three dimensional room fitted with a windcatcher based on the different inlet designs. The divergent inlet has captured the highest air flow with a difference of approximately 3% compared to the uniform inlet and 5% difference compared to the bulging-convergent inlet.


2020 ◽  
Vol 12 (3) ◽  
pp. 986 ◽  
Author(s):  
Mohammad Akrami ◽  
Akbar A. Javadi ◽  
Matthew J. Hassanein ◽  
Raziyeh Farmani ◽  
Mahdieh Dibaj ◽  
...  

The rise in the human population, its density and scarcity of resources require cost-effective solutions for sustainable energy and water resources. Smart and sustainable agriculture is one important factor for future green cities to tackle climate change as a cost-effective solution to save energy and water. However, greenhouses (GH) require consistent ventilation due to their internal temperatures, and this can be an energy-intensive operation. Therefore, it is necessary to analyse the potential factors involved. In this study, the effect of vent configuration of a mono-span greenhouse with roof and side vents at low wind speeds was investigated using computational fluid dynamics (CFD). The validated simulations were then performed on different models to analyse the effects of the vents’ locations on the ventilation requirements. The side vents were found to contribute most to the ventilation. The position of the side vent was found to affect the convection loop in the greenhouse and the air velocity at the plant level. The humidity was shown to be highest under the windward side vent. The roof vent was found to affect the temperature and air velocity in the roof of the greenhouse but had very little effect on the distributions at the plant level.


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