Simulasi Pencahayaan Terowongan Tomang Siang Hari Menggunakan Lampu LED

Pencahayaan terowongan pada siang hari sangat tergantung pada cahaya matahari, khususnya zona akses dan zona ambang. Intensitas cahaya pada zona tersebut harus dapat mengimbangi intensitas cahaya matahari di muka terowongan. Untuk itu pencahayaan buatan yang akan ditempatkan di zona akses dan zona ambang harus di tata sesuai adanya cahaya matahari di muka terowongan. Pada malam hari, zona ambang sampai dengan zona exit harus mempunyai iluminansi dan luminansi yang sama, dan nilainya tidak jauh berbeda dengan iluminansi dan luminansi yang ada pada jalan umum sebelum dan sesudah terowongan. Namun pada siang hari setiap zona harus mempunyai iluminansi dan luminansi yang berbeda. Penelitian ini mengambil data dari terowongan Tomang, terowongan ini terdiri dari terowongan ke arah Tangerang dengan perkiraan kecepatan rata-rata kendaraan sebesar 60 km/jam. Panjang terowongan 120 m, lebar 7 m, tinggi 4 m. Penelitian yang berupa simulasi ini menggunakan lampu LED, sesuai yang saat ini terpasang sejumlah 15 buah, sebelumnya menggunakan lampu HPS 250 Watt, sebanyak 20 buah, dengan jarak antar lampu 6 m. Hasil penelitian menunjukkan bahwa pencahayaan terowongan Tomang saat ini kurang tepat untuk siang hari, karena pada zona ambang pencahayaannya kurang dapat memenuhi luminansi cahaya matahari. Akibatnya pada siang hari zona ambang nampak gelap (terjadi adanya black hole phenomena). Sementara pada malam hari menghasilkan iluminansi dan luminansi yang berlebih, yaitu iluminansi 104 lux dan luminansi 9,96 cd/m2 yang lebih besar dari standar SNI 20 lux - 25 lux dan 2 cd/m2. Penggunaan lampu LED menghasilkan luminansi lebih tinggi dengan daya lebih minimal, dari pada lampu HPS

Building Envelope Design Optimization of a Hypothetical Classroom Considering Energy Consumption, Daylighting, and Thermal Comfort: Case Study in Lhokseumawe, Indonesia

This study evaluated the building performance of a hypothetical elementary school classroom considering its annual energy consumption, daylight criteria, and adaptive thermal comfort in Lhokseumawe, Indonesia. Variations in building materials, construction, and horizontal shading features were evaluated for the most optimal design solution. The aim was to optimize the multi-performance criteria as an integrated sustainable design solution for a typical classroom in Indonesia. To achieve this objective, the study utilized a computational simulation method using Rhinoceros, Grasshopper, and Ladybug Tools platforms. The optimization was conducted with Galapagos, an engine based on a genetic algorithm. The results suggest that the optimal solution achieved 100% sDA300/50% and more than 96% UDI100-3000lx. The annual thermal comfort percentage was also increased to over 90%, while the energy consumption was reduced by 20% compared to the baseline design

Pemodelan dan simulasi pencahayaan alami dalam bangunan di Indonesia

INDONESIA Pencahayaan alami dalam bangunan telah lama diketahui memiliki kontribusi besar tidak hanya dalam mengurangi penggunaan energi, tetapi juga dalam memberi pengaruh positif terkait dengan kesehatan dan kesejahteraan penghuni. Ditinjau dari segi kerekayasaan, tantangan utama yang dihadapi dalam konteks desain pencahayaan alami dalam bangunan ialah bagaimana sumber cahaya alami (matahari) yang tersedia dapat digunakan semaksimal mungkin untuk memenuhi persyaratan kinerja visual, dengan tetap meminimalkan risiko ketidaknyamanan visual dan penggunaan energi. Dengan kata lain, pencahayaan alami harus dirancang untuk mendukung terciptanya desain bangunan 'berkinerja tinggi', sesuai dengan berbagai objektif tersebut

Verification tests of a mirror box type artificial sky without and with building scale model

A mirror box type artificial sky for simulating the CIE standard overcast sky has been designed and constructed, while the verification method has been developed and tested. Ratio between the mirror height above the workplane and the room length is 60:133 or 0.451, whereas the ratio between the mirror height above the workplane and the room width is 5:9 or 0.556. Taking the CIE standard overcast sky as reference, indoor illuminance ratios at various elevation angles relative to the zenith is found to be more consistent than luminance ratios. The largest error of illuminance and luminance ratios are respectively 10% and 43%, obtained at 0° elevation angle. Horizontal workplane illuminance values are on average 11,400 lx, with illuminance uniformity U0 and U1 of respectively 0.92 and 0.86. Based on test results with a building scale model, four out of nine measuring points inside the model have small errors, four have medium error, and one has a large error of 25%. Most of the obtained errors are within the tolerable range of ± 21% from the ideal values. Based on the conducted tests, the constructed mirror box type artificial sky is considered appropriate to be utilised for its purpose. Keywords: Artificial sky, Mirror, Luminance, Illuminance, Building scale model, Verificatio

Evaluation on Glare from Vehicle Lamps and Effectiveness of Road Components as Glare Barriers

Vehicle lamps are vital components which are required to ensure the driver’s safety, particularly at nighttime. However, vehicle lamps may cause glare which can reduce visibility and create discomfort. The objectives of this research are to evaluate glare from car headlamp and motorcycle lamps; and to study the effectiveness of road components on highway median, i.e. paddle, vegetation, and jersey barriers (87.5 and 122.5 cm high) as glare barriers. Luminance from headlamps and vertical illuminance on observer’s eye were measured to observe glare effect on vehicle drivers, expressed with the de Boer rating. The experiment results show that car headlamps observed at nighttime by car drivers in highway without barriers, scored 3~5 (disturbing~acceptable) on the de Boer scale; while motorcycle lamps in static position scored 1~3 (unbearable~disturbing). Paddle was found to be the most effective glare barrier in highway, for it might reduce glare up to scale 6 (acceptable)

On the Interaction between the Depth and Elevation of External Shading Devices in Tropical Daylit Classrooms with Symmetrical Bilateral Openings

External shading devices are an important design feature in tropical buildings, particularly for climate mitigation. However, the interaction between the depth and elevation of the shading devices and their impact on indoor daylight performance is not fully understood, especially for the case of tropical buildings with bilateral openings. This study therefore aims to evaluate the design possibilities of external shading devices with various depth and elevation in terms of daylight performance for the case of tropical school classrooms with bilateral openings in an Indonesian city. A computational simulation method using Radiance is utilized to perform annual daylight metrics calculations. Geometry, material, and simulation settings are prepared using the Ladybug tool under Grasshopper for four building orientations, namely 0°, 45°, 90°, and 135°. Sensitivity and uncertainty analyses are conducted for all design combinations. The results show that the interaction between a shading device’s depth and elevation is unique, depending on the building orientation and the availability of direct sunlight. In general, shading elevation is more influential, compared to shading depth, on the observed daylight metrics and the combined objective functions at all orientations

Theoretical Impact of Building Façade Thickness on Daylight Metrics and Lighting Energy Demand in Buildings: A Case Study of the Tropics

In daylighting design, variation of building façade thickness (f) will result in variation of the daylight opening areas, which in turn will modify the values of daylight metrics within the space. However, studies dedicated to investigating the impact of varying f on indoor daylight metrics are relatively scarce. This study, therefore, aims to assess the theoretical impact of various façade thicknesses on various daylight metrics and lighting energy demands in a reference office space. Analytical calculations are performed using an outdoor diffuse illuminance profile of a tropical city. The building façade thickness values are varied within 0–0.50 m, at window-to-wall ratios (WWR) of 25%, 50%, and 75%. Based on sensitivity analysis, it is found that variation of f yields different impacts on the observed metrics, with sDA300/50% being the least influenced. Among all metrics in the central calculation point, DA300, UDI-a, and UDI-a′ yield relatively small coefficients of variation, and thus, have the lowest uncertainty with respect to f. Among all metrics for the entire room, sDA300/50% and sUDI-a50% have the lowest uncertainty, with interquartile ranges of no more than 0.4%. Overall, the contribution of this study is providing insight into the impact of façade thickness on various daylight metrics in indoor spaces, particularly in the worst-case scenario under the standard CIE overcast sky

Theoretical Impact of Building Façade Thickness on Daylight Metrics and Lighting Energy Demand in Buildings: A Case Study of the Tropics

In daylighting design, variation of building façade thickness (f) will result in variation of the daylight opening areas, which in turn will modify the values of daylight metrics within the space. However, studies dedicated to investigating the impact of varying f on indoor daylight metrics are relatively scarce. This study, therefore, aims to assess the theoretical impact of various façade thicknesses on various daylight metrics and lighting energy demands in a reference office space. Analytical calculations are performed using an outdoor diffuse illuminance profile of a tropical city. The building façade thickness values are varied within 0–0.50 m, at window-to-wall ratios (WWR) of 25%, 50%, and 75%. Based on sensitivity analysis, it is found that variation of f yields different impacts on the observed metrics, with sDA300/50% being the least influenced. Among all metrics in the central calculation point, DA300, UDI-a, and UDI-a′ yield relatively small coefficients of variation, and thus, have the lowest uncertainty with respect to f. Among all metrics for the entire room, sDA300/50% and sUDI-a50% have the lowest uncertainty, with interquartile ranges of no more than 0.4%. Overall, the contribution of this study is providing insight into the impact of façade thickness on various daylight metrics in indoor spaces, particularly in the worst-case scenario under the standard CIE overcast sky

Computational modelling and simulation to mitigate the risk of daylight exposure in tropical museum buildings

In museum design and operation, daylight is typically discouraged due to high risk of damaging the display objects. However, past studies in high-latitude regions have shown the possibility to apply daylight in museums, so long as it is carefully planned, and the display objects are not from the category of high responsive materials. In the tropical region, the influence of daylighting on light exposure on museum objects is still unknown. This study therefore aims to assess and mitigate the impact of annual daylight exposure on objects with low responsive materials in a tropical daylit museum building. Annual daylight modelling and simulation are performed to achieve the objective, followed with Morris sensitivity analysis and Mahalanobis distance classifier to optimise the outcome. It is found that either WWR or glazing transmissivity gives the greatest influence on the performance indicators. Based on the proposed optimisation algorithm, it is possible to determine the optimum solutions satisfying the performance indicators target, for a certain opening type. Overall, the contribution of this study is the proposed computational modelling and simulation methods to mitigate the exposure risk while optimising daylight as a renewable energy source