scholarly journals Effect of Sky Discretization for Shading Device Calculation on Building Energy Performance Simulations

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1381
Author(s):  
Ismael R. Maestre ◽  
Juan Luis Foncubierta Blázquez ◽  
Francisco Javier González Gallero ◽  
J. Daniel Mena Baladés
Keyword(s):  
Solar Energy ◽  
Computational Cost ◽  
Maximum Error ◽  
Building Energy ◽  
Energy Performance ◽  
Natural Lighting ◽  
Building Surfaces ◽  
Shading Devices ◽  
Shading Device ◽  
Angular Discretization

The calculation of sunlit surfaces in a building has always been a relevant aspect in building energy simulation programs. Due to the high computational cost, some programs use algorithms for shading calculation for certain solar positions after discretization of hemispherical sky. The influence of the level of discretization on the estimation of incident direct radiation on building surfaces, as well as on the required computational times, are studied in this work. The direct solar energy on a window for a year, with simulation time steps of five minutes, has been simulated by using an algorithm based on Projection and Clipping Methods. A total of 6144 simulations have been carried out, varying window sizes, window orientations, typologies of shading devices, latitudes and discretization levels of the hemispherical sky. In terms of annual incident solar energy, the results show that maximum error values are about 5% for a low level of angular discretization. Errors up to 22% in hourly incident solar energy have been estimated for some of the configurations analysed. Furthermore, a great number of configurations show errors of shading factor on a window of up to 30%, which could be most relevant in studies of natural lighting. The study also shows that the improvement achieved by the most accurate discretization level implies an increase in computational cost of about 30 times.

scholarly journals THERMAL-DAYLIGHTING BALANCE THROUGH BUILDING SHADING DEVICES: A REVIEW ON FACTORS AND METHODS

2021 ◽  
Vol 8 (3) ◽  
pp. 157
Author(s):  
Aimi Zahirah Zulkarnain ◽  
Mohd Najib Mohd Salleh ◽  
Zalena Abdul Aziz
Keyword(s):  
Energy Performance ◽  
Sustainable Building ◽  
High Performing ◽  
Indoor Space ◽  
Performance Factors ◽  
Negative Effect ◽  
Shading Devices ◽  
Shading Device ◽  
Optimum Balance ◽  
Parameter Relation

Daylighting is interpreted as natural sunlight allowed into an indoor space. Passive lighting strategies are considered fundamental in achieving a high performing sustainable building, which affects the visual and thermal comfort, and energy performance of a building. Many strategies in controlling daylighting are known, however, the wrong implementation can lead to a negative effect. The results obtained need to reach a balance between daylighting and thermal performance. This review is conducted to analyse the concept and factors that affect the balance through different research parameters. The performance factors include energy, comfort and perception or view. The different methods of achieving the balance are categorized into three, which are parameter relation, combination, and multi-objective optimization. Building shading devices are considered as one of the major solutions to reach thermal-daylighting balance. Through a comprehensive review, adjustable shading control is recommended as a better option for building shading device for buildings to achieve the optimum balance.

A Performance Comprehension of Various Numerical Estimators for Variance-Based Sensitivity Analysis in Building Energy Simulations

2019 ◽  
Author(s):  
Rasool Koosha ◽  
Fatemeh Shahsavari
Keyword(s):  
Sensitivity Analysis ◽  
Building Materials ◽  
Computational Cost ◽  
Residential Building ◽  
Building Energy ◽  
Energy Performance ◽  
Test Case ◽  
Sensitivity Index ◽  
Energy Simulations ◽  
High Level

Abstract In the building energy performance simulation, the uncertainty analysis (UA) couples to the sensitivity analysis (SA) to handle ever-existing uncertainties; induced by the sources of uncertainty including random occupants behavior and degradation of building materials over time. As a building simulation tool reaches to a high level of complexity, it becomes more challenging for the sensitivity analysis to deliver reliable outputs; thus the accuracy of the SA results substantially depends upon the number of sample sets or the type of analysis performed. This paper describes a variance-based SA tool integrated into a building Resistance-Capacitance (RC) thermal model. Then, for a hypothetical residential building test case, three distinct first-order sensitivity index simulators and three total sensitivity index simulators are implemented and compared in terms of the dependency of results on the sample size, i.e., the demand for the computational cost.

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

Energy Consumption Simulation for Residential Buildings With Shading Devices in Different Regions

2007 ◽  
Author(s):  
Junjie Liu ◽  
Xiaojie Zhou ◽  
Zhihong Gao
Keyword(s):  
Energy Consumption ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Energy ◽  
Energy Performance ◽  
Indoor Environments ◽  
Total Energy Consumption ◽  
South West ◽  
Shading Devices ◽  
Energy Consumption Simulation

With the development of energy saving, it is needed to calculate the energy consumption of the residential building, particularly accurate dynamic energy consumption. Fixed shading devices are wildly used to save building energy because they prevent undesirable heat coming through the windows during the “overheated period”, just as in summer, which can ameliorate the indoor environments and reduce the energy consumption of air-conditioning in summer. But they will also prevent solar energy which can be used in winter to enter windows. So it is very important to be able to determine the optimal shading devices of windows. The overhangs and vertical-shading devices are representative to study the different energy performance in summer and winter, in an actual dwell house. On the other hand, fixed shading devices can weaken the effect of daylighting, so we would take both the total energy consumption and rooms’ daylighting into account. In this study, we choose several typical dwelling houses in different cities located in north, south, west, east and central region of China respectively. We calculated energy consumption of those models by using Energyplus program, and compared the shading performance of horizontal and vertical shading devices, then optimal configuration dimensions of horizontal shading devices are recommended on the basis of different requirements for solar heat gains in winter and in summer for those typical dwelling houses.

Influence of selected solar positions for shading device calculations in building energy performance simulations

2015 ◽  
Vol 101 ◽  
pp. 144-152 ◽  
Author(s):  
Ismael R. Maestre ◽  
Juan Luis Foncubierta Blázquez ◽  
Francisco Javier González Gallero ◽  
Paloma R. Cubillas
Keyword(s):  
Building Energy ◽  
Energy Performance ◽  
Building Energy Performance ◽  
Shading Device

scholarly journals The Effect of Depth Shading Device on Inner Space Illumination in Jakarta

2019 ◽  
Vol 1 (1) ◽  
pp. 23-29
Author(s):  
Murwantoro Panghargiyo
Keyword(s):  
Reference Point ◽  
Strong Influence ◽  
The Other ◽  
The South ◽  
Natural Lighting ◽  
The North ◽  
Illumination Effect ◽  
North Direction ◽  
Shading Devices ◽  
Shading Device

This research tries to reveal the performance of shading devices towards quantity of natural lighting entering the room. Investigation concerning shading devices (ratio between the depth of shading devices and the height of fenestration) that suitable with illumination standard needs to be done. This research also tries to find out the influence of shading devices orientation on illuminance received by the room. This research examines the performance of three types external shading devices (eggcrate, overhang, sidefins) towards natural lighting entering the room. The analysis performed by Radiance IES software for illuminance performance entering the room. Maximum illuminance reduction for three types of shading device achieved to north direction in R1 reference point. While minimum reduction for overhang and sidefins achieved to south orientation in R2 reference point. Except for eggcrate minimum illuminance reduction achieved to west direction in R2 reference point. It can be concluded that in general the three basic models of shading device have a strong influence on the direction towards the north and have a small effect on the direction of the south. In addition to the three basic elements of the shading element, the type of eggcrate shading device has the greatest effect of reducing illumination compared to the other two types. While the sidefins type has the smallest illumination effect.

scholarly journals Neural network for indoor airflow prediction with CFD database

2021 ◽  
Vol 2069 (1) ◽  
pp. 012154
Author(s):  
Q Zhou ◽  
R Ooka
Keyword(s):  
High Speed ◽  
Computational Cost ◽  
Three Dimensional ◽  
Building Energy ◽  
Energy Performance ◽  
Design Stage ◽  
Indoor Environmental Quality ◽  
Indoor Airflow ◽  
Building Energy Performance ◽  
Time Consumption

Abstract Energy efficiency and indoor thermal comfort are both important in built environment, making it necessary to simultaneously take into consideration of the two aspects, building energy performance and indoor environmental quality, at the design stage. Coupled simulation between building energy simulation (BES) and computational fluid dynamics (CFD) enables providing each other complementary information with regard to building energy performance and detailed indoor environment conditions; however, the main drawback of CFD in computational cost limits its application. Neural networks (NNs) are considered as promising alternatives for CFD due to their advanced modelling abilities and high-speed computational powers. This research aims to confirm the feasibility of NN for indoor airflow prediction, which extends previous studies from two-dimensional to three-dimensional indoor space for more realistic conditions. The NN receives boundary conditions as input and outputs corresponding velocity and temperature distributions. Comparisons were made between NN predictions and CFD simulations regarding accuracy and time consumption on testing cases. The results show that the NN reproduces indoor airflow and thermal distributions with relative errors less than 12%. Time consumption for predicting the testing cases is reduced by 80% with the NN. The feasibility of NN for fast and accurate indoor airflow prediction is confirmed.

scholarly journals Efficient Shading Device as an Important Part of Daylightophil Architecture; a Designerly Framework of High-Performance Architecture for an Office Building in Tehran

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8272
Author(s):  
Hassan Bazazzadeh ◽  
Barbara Świt-Jankowska ◽  
Nasim Fazeli ◽  
Adam Nadolny ◽  
Behnaz Safar ali najar ◽  
...  
Keyword(s):  
High Performance ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Office Buildings ◽  
Building Performance ◽  
Visual Comfort ◽  
Different Seasons ◽  
Good Potential ◽  
Shading Devices ◽  
Shading Device

(1) Background: considering multiple, and somehow conflicting, design objectives can potentially make achieving a high-performance design a complex task to perform. For instance, shading devices can dramatically affect the building performance in various ways, such as energy consumption and daylight. This paper introduces a novel procedure for designing shading devices as an integral part of daylightophil architecture for office buildings by considering daylight and energy performance as objectives to be optimal. (2) Methods: to address the topic, a three-step research method was used. Firstly, three different window shades (fixed and dynamic) were modeled, one of which was inspired by traditional Iranian structures, as the main options for evaluation. Secondly, each option was evaluated for energy performance and daylight-related variables in critical days throughout the year in terms of climatic conditions and daylight situations (equinoxes and solstices including 20 March, 21 June, 22 September, and 21 December). Finally, to achieve a reliable result, apart from the results of the comparison of three options, all possible options for fixed and dynamic shades were analyzed through a multi-objective optimization to compare fixed and dynamic options and to find the optimal condition for dynamic options at different times of the day. (3) Results: through different stages of analysis, the findings suggest that, firstly, dynamic shading devices are more efficient than fixed shading devices in terms of energy efficiency, occupants’ visual comfort, and efficient use of daylight (roughly 10%). Moreover, through analyzing dynamic shading devices in different seasons and different times of the year, the optimal form of this shading device was determined. The results indicate that considering proper shading devices can have a significant improvement on achieving high-performance architecture in office buildings. This implies good potential for daylightophil architecture, but would require further studies to be confirmed as a principle for designing office buildings.

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