Daylighting Performance Of Building Research Articles

Optimizing the indoor thermal environment and daylight performance of buildings with PCM glazing

With the development of energy efficient technologies for glass envelopes, using thermal storage techniques to improve their thermal inertia has become a trend in research. In the present study, the heat transfer and day-lighting models of a building with PCM glazing curtain wall (PGC) were developed. Multiple parameters such as glazing internal surface temperature, PCM liquid phase rate, indoor temperature, natural illumination, and daylighting coefficient were quantitatively analyzed to evaluate their indoor thermal environment and daylighting performance. The results show that the application of PGC can significantly improve indoor temperature uniformity and indoor thermal comfort compared to silica aerogel glass curtain wall (SGC) and hollow glass curtain wall (HGC). By filling 10 mm thick PCM, the temperature fluctuation of the inner surface of the glass and the midpoint temperature of the room can be reduced by 35 %, the peak temperature of the inner surface of the glass can be delayed by 0.89 h, and the average indoor natural light value and indoor daylight factor are satisfactory at 453.26 lx and 9.63 %, respectively. However, as the thickness of the PCM increases to 15 and 20 mm, the liquid fraction of the PCM and the energy storage performance of the PGC are greatly reduced, and natural daylighting does not meet the GB/t-50033-2013 limit.

Multi-objective evolutionary optimization of photovoltaic glass for thermal, daylight, and energy consideration

The potential of fenestration systems is increased by incorporating photovoltaic technology into windows. This recently developed technology enhances the ability to generate energy from the building façade, improve the thermal and daylight performance of buildings, and visual comfort of occupants. Integrating an evolutionary optimization algorithm into this technology is one of the possible sustainable solutions to enhance building performance and minimize environmental impact. This paper uses a genetic evolutionary optimization algorithm to explore the optimum performance of photovoltaic glass in an architecture studio regarding annual energy consumption, energy generation, and daylight performance. Design variables include a window-to-wall ratio (i.e., window size and location) and amorphous-silicon thin-film solar cell transparency to generate optimum Pareto-front solutions for the case building. Optimization objectives are minimizing annual thermal (i.e., heating and cooling) loads and maximizing Spatial Daylight Autonomy. Optimized results of low-E semi-transparent amorphous-silicon photovoltaic glass applied on the façade show that the spatial daylight autonomy is increased to 82% with reduced glare risk and higher visual comfort for the occupants. Photovoltaic glass helped reduce the selected room's seasonal and annual lighting loads by up to 26.7%. Lastly, compared to non-optimized photovoltaic glass, they provide 23.2% more annual electrical energy.

Bistable kinetic shades actuated with shape memory alloys: prototype development and daylight performance evaluation

Kinetic façade systems can adjust to different environmental conditions, thereby improving daylight performance in buildings. Bistable laminates present large deflections and can maintain their state without continuous energy supply, appealing features for kinetic applications. Nevertheless, these engineered materials have yet to be studied for their potential for improving daylight performance in buildings. This study sought to test the daylight performance of a kinetic bistable screen using a case study approach that combines experimental testing and building performance simulation. This paper details research to design and fabricate the shading screen and the experimental testing of the screens’ daylight performance. First, we focus on the design of a holder mechanism, which relies on a string system and shape memory alloys that actuate bistable flaps. Second, we experimentally collect data on daylight performance and compare it to simulation data to validate a daylight model. Results show that the designed bistable screen can increase the hours of adequate daylight throughout the year versus baseline cases, particularly when oriented south and east. The study suggests that bistable kinetic screens can help improve daylight performance in buildings.

Comparative Study on Computer Simulation of Solar Shading Performance with Heliodon and Artificial Sky

Current technological advancement and the requirement for sustainability-driven practices has birthed increased demands for accuracy in performance and assessment of energy consumption in the built environment. Energy-efficient and sustainable building projects are to large extents dependent on achieving functional solar shading and sufficient daylighting in building interiors. Hence, the understanding and adequate evaluation of the sun and its dynamic influence on buildings right at the early stage of planning and design is essential for the development of performance-driven building designs. In this study, the performance simulation results of Integrated Environmental Solutions <Virtual Environment> software program modules are examined for accuracy in executing performance analysis of solar shading. This study assesses the shading prediction of Suncast; a virtual solar shading calculation tool, and RadianceIES for measuring daylight availability in a tropical climate region. The evaluation of shading performance with Suncast was validated through physical experiment by comparing the results obtained therein with shading analysis outcomes generated on a scale model with the aid of a heliodon. Likewise, RadianceIES daylighting simulations were compared with measurements realised from an artificial sky simulator. The results were further subjected to correlation tests to determine the relationship between simulation and physical experiment results. The computational evaluation approach presented more efficient means of conducting the performance simulations over the physical experiment methods which were limited by mechanical design of the components. Suncast and RadianceIES simulation results presented comparable equivalence with measurement output acquired from the heliodon and artificial sky respectively, with minimal variations in accuracy. Thus, demonstrating the ability of the computational simulation program in accurately predicting solar shading and daylight performance in buildings, this could benefit architects in the proper and efficient design of shading devices for building facades at early design stages.

A human-centric approach to assess daylight in buildings for non-visual health potential, visual interest and gaze behavior

This paper introduces a novel approach for the assessment of daylight performance in buildings, venturing beyond existing methods that evaluate 2-dimensional illumination and comfort within a fixed field-of-view, to predict human responses to light concerning non-visual effects, visual interest, and gaze behavior in a visually immersive scene. Using a 3D rendered indoor environment to exemplify this coordinated approach, the authors assess an architectural space across a range of view directions to predict non-visual health potential, perceptual visual interest, and gaze behavior at the eye level of an occupant. This method allows the authors to explore and demonstrate the impact of space, time, and sky condition on three novel daylight performance models developed to predict the effects of ocular light exposure using a human-centric approach. Results for each model will be presented in parallel and then compared to discuss the need for a multi-criteria assessment of daylight-driven human responses in architecture. A parallel and comparative approach can allow the designer to adapt the architectural space based on the program use and occupants needs.

실내 주광조도 간이 예측식을 활용한 담천공 시의 자연 채광 성능 평가

Daylight is very useful to control the indoor environment, and can save energy in buildings. So it is necessary to evaluate the daylighting performance of buildings. We proposed a simplified equation that can be used in the early stages of design. And we verified the equation by using the measured illuminance data from the 1/5 scale model. We compared the calculated indoor illuminances and measured illuminance including Daylight Factors of scale model in order to verify the applicability of the simplified equation, and proved the analyzed values are acceptable. When we have a target value of the Daylight Factor, we just have to determine the window area, transmittance of the glazing system, and indoor surface reflectance, then can achieve it with this simplified equation.

A Guide for Building Daylight Scale Models

Scale models are used frequently to evaluate the daylighting performance of buildings. In order to get accurate results, there are several rules to respect when building these scale models. Some of these rules are universal, while others depend on the measurement and observation devices, the type of sky under which the study is carried out, and the objectives of the study. This paper, based on the author's experience and on a literature review, presents rules to respect when building a mock-up for daylighting studies. These rules are illustrated by project examples that were tested under the Belgian artificial skies (single-patch sky and sun simulator, mirror box and mechanical sun).