Passive Design Strategies for Energy Efficient Buildings in the Arabian Desert

This study aims to assess passive design features through the extensive modifications of building envelopes to affect the energy efficiency of residential buildings in hot arid climates. In support of the aim of this research, the annual electric energy bill of a typical residential building in Sharurah was collected and analyzed. Then, the DesignBuilder simulation program was used to investigate how different modifications of building envelopes could affect the energy consumption of the residential buildings under common scenarios. Varied thermal insulation, different types of glass, shading devices, and green roof were investigated with this perspective. The simulation results show that thermal insulation can significantly reduce annual energy consumption by as high as 23.6%, followed by green roofs. In contrast, shading devices and glazing system types were fewer superiors. The results also indicate that the effective combination of certain strategies can reduce total energy consumption by 35.4% relative to the base case (BC) of this research.

Design Optimisation of Fixed and Adaptive Shading Devices on Four Façade Orientations of a High-Rise Office Building in the Tropics

Optimisation of shading devices in buildings is a broadly investigated topic; however, most studies only focus on a single façade orientation, since the observed buildings are typically located in high latitude regions. However, in tropical regions, optimisation of all façade orientations is required due to the relatively high solar radiation and long sunshine duration. While adaptive shading devices are a promising solution, they are not without disadvantages, and as such a combination of adaptive shading devices and a fixed shading device shall be considered. This research therefore aims to design the optimum internal shading devices on four façade orientations of a high-rise office building in a tropical city, considering fixed and adaptive shading design options, and to determine the impact on annual daylight performance using computational modelling and simulation. The simulation is carried out under: (1) fixed design option, focusing on the numbers and width of slats; and (2) adaptive design option, focusing on the slat angle on various conditions. It is found that both sDA300/50% and ASE1000,250 are only influenced by the orientation. Under the fixed design option, the sDA300/50% and ASE1000,250 targets can be achieved only on the north and south façades, and accordingly the adaptive design option shall be implemented on the east and west façades. Overall, this study contributes to knowledge regarding the optimisation of shading devices in high-rise buildings in the tropics, considering the daylight admission from the four cardinal orientations.

Integrating Daylighting with Task-Ambient Lighting for Enhanced Energy Savings in Office Spaces

Daylighting has been widely studied as a fundamental aspect of spatial illumination and energy efficient façade design. Effective installation and control of shading devices diminishes the adverse effects of prevailing climatic conditions on building envelope performance and reduces resultant lighting and cooling energy consumption. Task-ambient lighting as a free-standing approach has also been proven to reduce lighting energy consumption compared with typical general ambient lighting. This study estimates the energy saving potential of integrating daylighting through fixed external horizontal shading slats with task lighting. Spot measurements were taken in a test room to validate a daylight calculation program. Full year indoor work plane daylight simulations were performed for office spaces of different floor areas and varying window to wall ratios. Indoor daylight quality was assessed using the Useful Daylight Illuminance metric and three different task lighting schemes explored. Lighting energy savings of 10% to 90% were estimated under the three schemes in comparison to similar office spaces with common unshaded heat reflective glazing.

A short review on passive strategies applied to minimise the building cooling loads in hot locations

Cooling and air-conditioning systems are responsible for the highest energy consumption in buildings located in hot areas. This high share does not only increase the building energy demand cost but also increases the environmental impact, the topmost awareness of the modern era. The development of traditional systems and reliance on renewable technologies have increased drastically in the last century but still lacks economic concerns. Passive cooling strategies have been introduced as a successful option to mitigate the energy demand and improve energy conservation in buildings. This paper shed light on some passive strategies that could be applied to minimise building cooling loads to encourage the movement towards healthier and more energy-efficient buildings. For this purpose, seven popular passive technologies have been discussed shortly: multi-panned windows, shading devices, insulations, green roofing, phase change materials, reflective coatings, and natural ventilation using the windcatcher technique. The analysis of each strategy has shown that the building energy could be improved remarkably. Furthermore, adopting more passive strategies can significantly enhance the building thermal comfort even under severe weather conditions.

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

(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.

RE-EVALUATION OF THE EGYPTIAN CODE OF HOUSING AND ENERGY CONSUMPTION WITH EMPHASIS ON SHADING DEVICES ROTATION ANGLES

The passive system technique is dynamically used as an alternative to the active system, in order to minimize the peak loads and the total EUI in kWh/ m2 for any building prototype. Sun breaker or shading device is a basic traditional method and Mashrabiya previously used for privacy and reduces the heat gained and emitted from sun`s rays, in addition to the fabricated wood material and its specs of bad conductor. the study aims to investigate the effect of rotational shading devices around the y-axis, will the rotation have a significant impact on the EUI or not? The research methodology is built upon generative modeling tool of parametric design, Rhinoceros Version 6.0, with the cooperation of Grasshopper, Ladybug& Honeybee, and Toolbox. Five hundred running simulations are carried out to determine the optimal angle of rotation with maximum reduction in cooling loads, and the interpretation is 30°. Two linear regression equations are derived out of this valuable study to deduce the correlation between independent and dependent variables when the sun breaker material is matt or reflective, and how the total EUI kWh/m2 can be minimized?

Artificial Intelligence for Detecting Indoor Visual Discomfort from Facial Analysis of Building Occupants

Glare is a common local visual discomfort that is difficult to identify with conventional light sensors. This article presents an artificial intelligence algorithm that detects subjective local glare discomfort from the image analysis of the video footage of an office occupant’s face. The occupant’s face is directly used as a visual comfort sensor. Results show that it can recognize glare discomfort with around 90% accuracy. This algorithm can thus be at the basis of an efficient feedback control system to regulate shading devices in an office building.

Facade control systems for optimal daylighting: A case of Kerala

Indoor environmental quality is one of the most important aspects to be considered while designing buildings. Design decisions taken to ensure indoor environmental quality depends upon the specific location, climate, form, orientation and materials used for the construction of the building. In addition to ensuring comfort and optimal occupant conditions, these design decisions also impact the overall energy consumption of the building. The design of the building envelope is of more importance in regions that receive a huge amount of solar radiation. Kerala, falling in the Tropical belt, have buildings designed (or supposed to be designed) with sufficient roofing/shading overhangs to avoid penetration of solar radiation, and direct glare towards the inside. Well-designed shading devices provide the best shading during overheated periods thus lesser heat gain or cooling load. The form of shading devices influences day-lighting inside the building. This paper intends to explore different types of shading devices and façade control systems, and their impact on daylighting inside a selected commercial building in Kerala. It concludes by identification of the most efficient design of the device in each type identified, through BIM modelling and lighting simulation, specific to the original building location, to ensure optimal daylighting while eliminating the undesirable effects of solar radiation.