scholarly journals Evaluating the Effect of External Horizontal Fixed Shading Devices’ Geometry on Internal Air Temperature, Daylighting and Energy Demand in Hot Dry Climate. Case Study of Ghardaïa, Algeria

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 348
Author(s):  
Sahar Magri Elouadjeri ◽  
Aicha Boussoualim ◽  
Hassan Ait Haddou
Keyword(s):  
Solar Radiation ◽  
Parametric Analysis ◽  
Energy Demand ◽  
Daylighting Simulation ◽  
Simulation Results ◽  
Shading Devices ◽  
Heating Loads ◽  
Shading Device ◽  
The City

The present study investigates the effect of fixed external shading devices’ geometry on thermal comfort, daylighting and energy demand for cooling and heating in the hot and dry climate of the city of Ghardaïa (Algeria). A parametric analysis was performed by using three software: RADIANCE 2.0 and DAYSIM 3.1 for daylighting simulation and TRNSYS.17 for thermal dynamic simulation. Three shading device parameters were assessed: the spacing between slats, the tilted angle and the slats installation. The vertical shading angle “VSA” is fixed; it is equal to the optimum shading angle measured for Ghardaïa. The simulation results indicate that fixed external shading devices have a significant impact on decreasing the energy demand for cooling; however, they are unable to reduce the total energy demand since they significantly increase heating loads. It was found that fixed external shading devices remove all risks associated with glare in summer by decreasing illuminance close to the window; however, they do not improve daylighting performance in winter because of glare. We note that even if the vertical shading angle “VSA” was the same for all cases, these did not present the same thermal and luminous behavior. This is mainly due to the amount and the way that the solar radiation penetrates space.

Improving Climatic Comfort of Citizens by Adjusting the Orientation and Extension of Physics of City Squares: Case Study of Yazd

2017 ◽  
Vol 05 (02) ◽  
pp. 1750012
Author(s):  
Fouad KHEIRABADI ◽  
Hooshmand ALIZADEH ◽  
Hossein NOURMOHAMMADZAD
Keyword(s):  
Solar Radiation ◽  
Correlation Method ◽  
The Body ◽  
Human Beings ◽  
The North ◽  
The Earth ◽  
The City ◽  
High Building ◽  
Software Measures

The heat of the earth is provided by solar radiation. A change in the angle of solar radiation and the surface of the earth causes changes in the ambient temperature. Sometimes, these changes reduce climatic comfort of human beings. Climatic comfort is established when there is a balance between excreted and absorbed temperatures of the skin of the body. Orientation and extension rates of physics of squares relative to the geographical north influence the amount of received direct sunlight in different months. Relevant studies show that the squares of the city of Yazd reduce the climatic comfort of its citizens; moreover, the physics of Yazd's squares apply various extension rates, which led to high building costs to citizens and relevant organizations. This study, by using the correlation method and R software, measures different orientation and extension rates of physics of squares in Yazd. It analyzes two models with orientation and physical extension as variables and evaluates the shade and sunlight in the space. The results reveal significant differences between desirable and undesirable options. Considering the climatic comfort of space users and residents at the same time, a rectangle with an extension ratio of one to several and the north-south orientation, making the lowest facade face the south, is the most appropriate physic for city squares.

Case Study: Performance Assessment of Various Sun Shades for Hot-Dry Climate

2013 ◽  
Vol 816-817 ◽  
pp. 875-881 ◽  
Author(s):  
R. Sairam ◽  
P.L. Raviteja ◽  
A. Naresh
Keyword(s):  
Energy Consumption ◽  
South India ◽  
Solar Heating ◽  
Heat Gain ◽  
Natural Lighting ◽  
Shading Devices ◽  
Shading Device ◽  
Study Performance

There are many reasons to control the amount of sunlight admitted into a building. In warm, sunny climates excess solar gain may result in high cooling energy consumption. In cold and temperate climates winter sun entering south-facing windows can positively contribute to passive solar heating; and in nearly all climates controlling and diffusing natural Illumination will improve day lighting. A Well-designed sun control and shading devices can dramatically reduce building peak heat gain and cooling requirements and improve the Natural lighting quality of building interiors. In this casestudy Shading Devices commonly found in India are evaluated to find Optimized Shading Device for Hot-Dry Climate of South India

Accounting of Climatic Features in Designing Solar Shading Devices

2018 ◽  
pp. 162-166
Author(s):  
Alexander T. Dvoretsky ◽  
Alexander V. Spiridonov ◽  
Igor L. Shubin ◽  
Ksenia N. Klevets
Keyword(s):  
Solar Radiation ◽  
Russian Federation ◽  
North Caucasus ◽  
Cooling Period ◽  
The North ◽  
Solar Shading ◽  
Federal Districts ◽  
The Russian Federation ◽  
Shading Devices ◽  
Shading Device

Zoning maps of the territory of the Russian Federation on solar radiation and outdoor temperature are given. It should provide for shading of fenestration during the cooling period of buildings, depending on the total amount of solar radiation and the temperature of the outside air. Depending on the amount of solar radiation, five zones are proposed in the territory of the Russian Federation. For each of the five zones, the cooling period of the building is proposed, on which the choice of the parameters of the solar ray daily cone depends on the shape of a solar shading device. A map of isolines of solar radiation for July in the North Caucasus and Southern Federal Districts of the Russian Federation is proposed, which can be used to calculate heat input through fenestration.

scholarly journals Assessment of the energy efficiency of a window system with a shading device of the egg-crate type

Vestnik MGSU ◽  
2021 ◽  
pp. 655-665
Author(s):  
Chan Ngoc Tran ◽  
Nguyen Thi Khanh Phuong ◽  
Ekaterina V. Gorbarenko
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
High Energy ◽  
Regression Equations ◽  
The Sun ◽  
Heat Gain ◽  
Window System ◽  
Gain Reduction ◽  
Shading Devices ◽  
Shading Device

Introduction. The article proposes a new energy efficiency assessment method based on a new technique used to calculate the window heat gain. The proposed method takes account of the coefficient of irradiance reduction by the sun shading device. The study was carried out for the shading device of the egg-crate type. Materials and methods. Calculations are based on the projection of a sunbeam performed for a fraction of a window area in the shade. They take account of the coefficient of irradiance reduction applied due to the presence of the sun shading device. A shading device reduces the irradiance, caused by diffused solar radiation, and coefficient Kbt is applied to demonstrate this process. This coefficient was identified in an experiment and expressed in the form of regression equations. To evaluate the energy efficiency with regard for the effectiveness of shading devices, coefficient of solar radiation gain reduction β was developed. This coefficient is described by the ratio of the value of solar radiation incoming through a glazed window in the presence of shading device QK to the value of solar radiation incoming through a glazed window that has no shading QKo. The software programme was used to verify the calculations of the heat gain from the solar radiation incoming through the window system with regard for the shading device in various geographical regions in summer (in Hanoi and Moscow). Results. The results, obtained using the proposed methodology and the observation data, show an insignificant difference in the relative value of β; and they demonstrate a major error when qwindow, or the absolute value of heat entering the room, is taken account of. The heat load, incoming through the window system, is down by 42–45 % in Moscow and by 45–53 % in Hanoi in the hottest period of the year if shading devices are used. Conclusions. The proposed methodology and computer software, used for a quick assessment of the energy efficiency of a window system equipped with shading devices, allow to design building envelopes that feature high energy efficiency in terms of air conditioning systems, given that coefficient of radiation gain reduction β is taken account of.

scholarly journals Effects of Densification on Urban Microclimate—A Case Study for the City of Vienna

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 511
Author(s):  
Wolfgang Loibl ◽  
Milena Vuckovic ◽  
Ghazal Etminan ◽  
Matthias Ratheiser ◽  
Simon Tschannett ◽  
...  
Keyword(s):  
Climate Change ◽  
Energy Demand ◽  
Green Roofs ◽  
Slight Reduction ◽  
Heat Island ◽  
Negative Effects ◽  
Street Level ◽  
The Impact ◽  
The City

Climate adaptation, mitigation, and protecting strategies are becoming even more important as climate change is intensifying. The impacts of climate change are especially tangible in dense urban areas due to the inherent characteristics of urban structure and materiality. To assess impacts of densification on urban climate and potential adaptation strategies a densely populated Viennese district was modeled as a typical sample area for the city of Vienna. The case study analyzed the large-scale densification potential and its potential effects on microclimate, air flow, comfort, and energy demand by developing 3D models of the area showing the base case and densification scenarios. Three methods were deployed to assess the impact of urban densification: Micro-climate analysis (1) explored urban heat island phenomena, wind pattern analysis (2) investigated ventilation and wind comfort at street level, and energy and indoor climate comfort analysis (3) compared construction types and greening scenarios and analyzed their impact on the energy demand and indoor temperatures. Densification has negative impacts on urban microclimates because of reducing wind speeds and thus weakening ventilation of street canyons, as well as accelerating heat island effects and associated impact on the buildings. However, densification also has daytime cooling effects because of larger shaded areas. On buildings, densification may have negative effects especially in the new upper, sun-exposed floors. Construction material has less impact than glazing area and rooftop greening. Regarding adaptation to climate change, the impacts of street greening, green facades, and green roofs were simulated: The 24-h average mean radiant temperature (MRT) at street level can be reduced by up to 15 K during daytime. At night there is only a slight reduction by a few tenths of 1 K MRT. Green facades have a similar effect on MRT reduction, while green roofs show only a slight reduction by a few tenths of 1 K MRT on street level. The results show that if appropriate measures were applied, negative effects of densification could be reduced, and positive effects could be achieved.

scholarly journals Uncertainties of Estimating a Town’s Carbon Footprint– Case Study El Gouna, Egypt

2019 ◽  
Vol 29 (1) ◽  
pp. 28-38
Author(s):  
Christoph Banhardt ◽  
Felix Hartenstein
Keyword(s):  
Carbon Footprint ◽  
Carbon Emissions ◽  
Energy Demand ◽  
Carbon Accounting ◽  
Fossil Energy ◽  
Wide Range ◽  
The City ◽  
Do So

Abstract Carbon accounting has become a valuable tool for expressing the fossil energy demand of products, organizational entities, or entire countries. About a decade ago, cities also began accounting their carbon emissions. The first major city to do so was London in 2009, stating a carbon footprint of 4.84 tCO2eq/(year*capita) for 2008. Nowadays, multiple rankings compare the carbon emissions of cities. For example, the Urban Land Magazine lists São Paulo as the city with the world’s lowest carbon emissions (1.4 CO2eq/(year*capita)). Such listings typically present the depicted emission values as scientifically indisputable numbers. However, a closer look at the applied methodology frequently reveals a wide range of implicit, often undisclosed assumptions at the foundation of the calculations. This paper analyses the uncertainties of carbon accounting on the city scale, using the example of the Red Sea resort town of El Gouna. The estimated value of El Gouna’s carbon footprint for the year 2014 is 14.3 tCO2eq/(year*capita). Third Scope emissions constitute the majority of El Gouna’s carbon footprint. Varying their underlying assumptions only slightly can lead to alterations of the results of more than 50%, questioning the robustness of the findings. To increase the robustness and the comparability of carbon accounting across cities, this paper suggests emphasizing Scope 1 and Scope 2 emissions, while limiting the role of Scope 3 emissions.

A COMPARISON OF FOUR DAYLIGHTING METRICS IN ASSESSING THE DAYLIGHTING PERFORMANCE OF THREE SHADING SYSTEMS

2017 ◽  
Vol 12 (3) ◽  
pp. 39-53 ◽  
Author(s):  
Mohamed Boubekri ◽  
Jaewook Lee
Keyword(s):  
The Other ◽  
Design Solution ◽  
Complex Task ◽  
Quantitative Metrics ◽  
Daylighting Simulation ◽  
The Mean ◽  
Shading Devices ◽  
Shading Device ◽  
Goals And Objectives ◽  
Performance Behavior

The assessment of the daylighting performance of a design solution is a complex task due to the changing nature of daylight. A few quantitative metrics are available to designers to assess such a performance, among them are the mean hourly illuminance (MHI), the daylight factor (DF), the daylight autonomy (DA) and the useful daylight illuminance (UDI). Each of these metrics has a purpose, a set of criteria and limitations that affect the outcome of the evaluation. When to use one metric instead of another depends largely on the design goals to be achieved. Using Design Iterate Validate Adapt (DIVA) daylighting simulation program, we set out to examine the performance behavior of these four metrics with the changing dimensions of three shading devices: a horizontal overhang, a horizontal louver system, and a vertical fin system, and compare their performance behavior as the orientation changes of the window to which these devices are attached. The context is a typical classroom of a prototypical elementary school. Our results indicate that not all four metrics behave similarly as we vary the size of each shading device and as orientation changes. The lesson learned is that not all daylighting metrics lead to the same conclusions and that it is important to use the metric that corresponds to the specific goals and objectives of the design and of the daylighting solution. The UDI is the metric that leads to outcomes most different than the other three metrics investigated in this paper.

Study of Interior Materials as Passive Fire Protection in Karaoke Building (Case Study: Masterpiece Signature Family KTV Medan)

2020 ◽  
Vol 4 (1) ◽  
pp. 30-43
Author(s):  
Saras Ayu Faradita ◽  
Vinky Rahman
Keyword(s):  
Fire Protection ◽  
Analytical Hierarchy Process ◽  
Passive Protection ◽  
Fire Incident ◽  
Fire Disaster ◽  
Passive Fire Protection ◽  
Protection Systems ◽  
Hierarchy Process ◽  
The City

The fire incident in karaoke buildings in Indonesia which claimed many lives has occurred several times. According to the National Academy of Science US, the smoke toxins that come out of the fire disaster cause 50-80% of deaths. Refers to the data, it is necessary to check further about the building material response to fire during a fire incident. Masterpiece Signature Karaoke is a karaoke building that classified as large and magnificent in the city of Medan which has various material so that it is necessary to study the interior material as passive fire protection. The purpose is to find out how to assess the reliability of fire passive protection regard to the interior materials and recommendations or descriptions of right interior material planning using the Analytical Hierarchy Process (AHP). This method is efficacious to solve the problem of reliability in using interior materials as passive fire protection in Masterpiece Signature Family KTV Medan building with the results of an Adequate Level of reliability. Then, design recommendations were given for the use of interior materials in karaoke building to improve the reliability results to be better.The results are useful as information for other researchers and karaoke buildings regarding passive fire protection systems at the Masterpiece Signature Family KTV Medan.

Emplacing Berlin: Digital Itineraries and Short-term Study Abroad in the City

2018 ◽  
Vol 12 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Richard B. Apgar
Keyword(s):  
Study Abroad ◽  
Urban Landscape ◽  
Physical Space ◽  
Short Term ◽  
Study Abroad Programs ◽  
Term Study ◽  
Digital Maps ◽  
Short Term Study ◽  
The City

As destination of choice for many short-term study abroad programs, Berlin offers students of German language, culture and history a number of sites richly layered with significance. The complexities of these sites and the competing narratives that surround them are difficult for students to grasp in a condensed period of time. Using approaches from the spatial humanities, this article offers a case study for enhancing student learning through the creation of digital maps and itineraries in a campus-based course for subsequent use during a three-week program in Berlin. In particular, the concept of deep mapping is discussed as a means of augmenting understanding of the city and its history from a narrative across time to a narrative across the physical space of the city. As itineraries, these course-based projects were replicated on site. In moving from the digital environment to the urban landscape, this article concludes by noting meanings uncovered and narratives formed as we moved through the physical space of the city.

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