scholarly journals Quantifying Fenestration Effect on Thermal Comfort in Naturally Ventilated Classrooms

2021 ◽  
Vol 13 (13) ◽  
pp. 7385
Author(s):  
Ibrahim Reda ◽  
Raouf N. AbdelMessih ◽  
Mohamed Steit ◽  
Ehab M. Mina

This study seeks to evaluate thermal comfort in naturally ventilated classrooms to draw sustainable solutions that reduce the dramatic energy consumed in mechanically ventilated spaces. Passive ventilation scenarios are generated using alternations of openings on the windward and leeward sides to evaluate their effects on thermal comfort. Twenty-eight experiments were carried in Bahrain during winter inside an exposed classroom, the experiments were grouped into five scenarios namely: “single-inlet single-outlet” SISO, “single-inlet double-outlet” SIDO, “double-inlet single-outlet” DISO, “double-inlet double-outlet” DIDO and “single-side ventilation” SSV. The findings indicate that single-side ventilation did not offer comfort except at high airspeed, while comfort is attained by using cross-ventilation at ambient temperature between 21.8–26.8 °C. The temperature difference between monitored locations and the inlet is inversely proportional to the number of air changes per hour. The DISO scenario accomplishes the lowest temperature difference. Using cross-ventilation instead of single-side ventilation reduces the temperature differences between 0.5–2.5 °C and increases airspeed up to three folds. According to the measured findings, the DISO cross-ventilation scenario is a valid sustainable solution adaptable to climatic variation locally and beyond with zero-energy consumption and zero emissions.

2020 ◽  
pp. 1420326X2096115
Author(s):  
Jaime Resende ◽  
Marta Monzón-Chavarrías ◽  
Helena Corvacho

Buildings account for 34% of world energy consumption and about half of electricity consumption. The nearly/Net Zero Energy Building (nZEB/NZEB) concepts are regarded as solutions for minimizing this problem. The countries of Southern Europe, which included the nZEB concept recently in their regulatory requirements, have both heating and cooling needs, which adds complexity to the problem. Brazil may benefit from their experience since most of the Brazilian climate zones present significant similarities to the Southern European climate. Brazil recently presented a household energy consumption increase, and a growing trend in the use of air conditioning is predicted for the coming decades. Simulations with various wall and roof solutions following the Brazilian Performance Standard were carried out in a low standard single-family house in three different climate zones in order to evaluate thermal comfort conditions and energy needs. Results show that in milder climate zones, achieving thermal comfort with a low energy consumption is possible, and there is a great potential to achieve a net zero-energy balance. In the extreme hot climate zone, a high cooling energy consumption is needed to provide thermal comfort, and the implementation of a nearly zero-energy balance may be more feasible.


2019 ◽  
Vol 4 (4) ◽  
pp. 109-124
Author(s):  
Hashir Usman

With every passing year, energy consumption in the world is increasing drastically. Most of the energy comes from fossil fuels which are also depleting in a fast manner. Buildings consume a significant amount of energy all over the world and the demand for energy is also increasing unremittingly in buildings. Developed countries are taking profound measures in order to make buildings energy efficient and sustainable by achieving nearly zero energy stage. Pakistan is facing a serious energy crisis from the past few decades. The building sector in Pakistan deserves special attention in this regard since the energy consumption in buildings in Pakistan is feverishly high. Many types of research have been carried out in Pakistan by the United Nations and Energy Department of Pakistan in order to devise applicable methods that not only provide thermal comfort to the occupants but also make a building energy efficient. Renewable energy also plays an important role in compensating building energy demands. It is easy to achieve nearly zero energy state in a good energy efficient building if it is coupled with renewable energy sources then it will make it self-sufficient in energy demand. A survey is also carried out to determine the thermal comfort of the occupants in different types of areas. Also, solar energy analysis is also taken into account to highlight the solar power potential in Pakistan. Several recommendations have also been suggested to implement energy efficiency measures in Pakistan.


2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Mohsen Mahdavi Adeli ◽  
Said Farahat ◽  
Faramarz Sarhaddi

Residential and commercial buildings consume approximately 60% of the world’s electricity. It is almost impossible to provide a general definition of thermal comfort, because the feeling of thermal comfort is affected by varying preferences and specific traits of the population living in different climate zones. Considering that no studies have been conducted on thermal satisfaction of net-zero energy buildings prior to this date, one of the objectives of the present study is to draw a comparison between the thermal parameters for evaluation of thermal comfort of a net-zero energy building occupants. In so doing, the given building for this study is first optimized for the target parameters of thermal comfort and energy consumption, and, hence, a net-zero energy building is formed. Subsequent to obtaining the acceptable thermal comfort range, the computational analyses required to determine the temperature for thermal comfort are carried out using the Computational Fluid Dynamics (CFD) model. The findings of this study demonstrate that to reach net-zero energy buildings, solar energy alone is not able to supply the energy consumption of buildings and other types of energy should also be used. Furthermore, it is observed that optimum thermal comfort is achieved in moderate seasons.


2020 ◽  
Vol 4 (1) ◽  
pp. 73
Author(s):  
Asep Yudi Permana ◽  
Karto Wijaya ◽  
Hafiz Nurrahman ◽  
Aathira Farah Salsabilla Permana

Abstract: Energy efficiency is a top priority in design, because design errors that result in wasteful energy will impact operational costs as long as the building operates. The opening protection in the facade should be adjusted according to their needs, for optimum use of sky light. Inhibiting the entry of solar heat into the room through the process of radiation, conduction or convection, optimum use of sky light and efforts to use building skin elements for shading are very wise efforts for energy savings. House construction planning must be careful and consider many things, including: physical potential. Physical potential is a consideration of building materials, geological conditions and local climate. Related to the issue of global warming that occurs in modern times, climate is a major consideration that needs to be resolved.The purpose of building design, especially in residential homes aims to create amenities for its inhabitants. Amenities are achieved through physical comfort, be it spatial comfort, thermal comfort, auditory comfort, or visual comfort.Energy waste is also caused by building designs that are not well integrated and even wrong and are not responsive to aspects of function, and climate. This is worsened by the tendency of the designers to prioritize aesthetic aspects (prevailing trends). The issue of green concepts and energy consumption efficiency through the Net Zero-Energy Buildings (NZE-Bs) program from the housing sector as a response to tackling global warming is already familiar in Indonesia, although its application has not yet been found significantly. Green concepts offered by housing developers are often merely marketing tricks and are not realized and grow the responsibility of the residents to look after them. Due to the lack of understanding of the green concept, housing developers tend to offer more a beautiful and green housing environment, not the actual green concept.Keyword: Socio-culture, Energy efficiency, Energy consumption, Environment. The green conceptAbstrak: Efisiensi energi merupakan prioritas utama dalam disain, karena kesalahan disain yang berakibat boros energi akan berdampak terhadap biaya opersional sepanjang bangunan tersebut beroperasi. Pelindung bukaan pada fasade sebaiknya dapat diatur sesuai kebutuhannya, untuk pemanfaatan terang langit seoptimal mungkin. Penghambatan masuknya panas matahari kedalam ruangan baik melalui proses radiasi, konduksi atau konveksi, pemanfaatan terang langit seoptimal mungkin serta upaya pemanfaatan elemen kulit bangunan untuk pembayangan merupakan upaya yang sangat bijaksana bagi penghematan energi. Perencanaan pembangunan rumah harus cermat dan mempertimbangkan banyak hal, antara lain: potensi fisik. Potensi fisik adalah pertimbangan akan bahan bangunan, kondisi geologis dan iklim setempat. Terkait dengan isu pemanasan global yang terjadi pada masa modern ini, iklim menjadi sebuah pertimbangan utama yang perlu diselesaikan.Tujuan desain bangunan khususnya pada rumah tinggal bertujuan menciptakan amenities bagi penghuninya. Amenities dicapai melalui kenyamanan fisik, baik itu spatial comfort, thermal comfort, auditory comfort, maupun visual comfort.Pemborosan energi juga disebabkan oleh desain bangunan yang tidak terintegrasi dengan baik bahkan salah dan tidak tanggap terhadap aspek fungsi, serta iklim. Hal tersebut diperparah yang kecenderungan para perancang lebih mementingkan aspek estetis (tren yang berlaku). Isu konsep hijau dan efisiensi konsumsi energi melalui program Net Zero-Energy Buildings (NZE-Bs) dari sektor perumahan sebagai respon untuk menanggulangi pemanasan global sudah tidak asing di Indonesia, walaupun penerapannya masih belum dapat ditemukan secara signifikan. Konsep hijau yang ditawarkan oleh pengembang perumahan seringkali hanya sebagai trik pemasaran belaka dan tidak diwujudkan serta ditumbuhkan tanggung jawab para penghuni untuk menjaganya. Akibat minimnya pemahaman mengenai konsep hijau tersebut, para pengembang perumahan cenderung lebih banyak menawarkan lingkungan perumahan yang asri dan hijau, bukan konsep hijau yang sebenarnya.Kata Kunci: Sosio-kultur, Efisiensi Energi, Konsumsi energi, Lingkungan, Konsep Hijau


2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.


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