Average Illuminance Level Research Articles

ANALISIS PENCAHAYAAN LAMPU PENERANGAN JALAN UMUM (LPJU) PADA JALAN TOL SEMAYANG

Several issues with public street lighting are often found and do not meet the Indonesian National Standard (SNI). Common problems include uneven spacing between streetlight poles, improper pole heights, poorly organized streetlight installations, and incorrect selection of lamp types and wattages according to the SNI standards. The lack of streetlights on busy road sections results in inefficient operation and discomfort for road users due to inadequate light intensity at the streetlight locations caused by various factors. To address these issues, solutions are needed to improve the existing situation, including energy-saving measures for public street lighting. Some necessary actions include replacing non-compliant streetlights and conducting evaluations by relevant authorities after installation works are completed. The existing condition of streetlights along the Semayang Toll Road shows an average illumination level produced by 150W SON-T lamps of 3.1 lux with light uniformity of 0.0, which does not comply with SNI 7391:2008. Simulation results using Dialux 4.13 software indicate that the average illumination level produced by Philips LED luminaires of 150W is 11 lux with a light uniformity of 0.106 lux, meeting SNI 7391:2008 requirements. Similarly, for Philips LED luminaires of 120W, the average illumination level is 11 lux with a light uniformity of 0.114 lux, thus meeting the standards. Based on the simulation results using Dialux 4.13 software, the use of 120W LED lamps for public street lighting on the Semayang Toll Road can lead to a 20% reduction in electricity consumption.

Research on the Design of Recessed Balconies in University Dormitories in Cold Regions Based on Multi-Objective Optimization

Thermal comfort and daylighting are vital components of dormitory environments. However, enhancing indoor lighting conditions may lead to increased annual energy consumption and decreased thermal comfort. Therefore, it is crucial to identify methods to reduce buildings’ energy costs while maintaining occupants’ thermal comfort and daylighting. Taking the dormitory building of Songyuan No. 2 at Shandong Jianzhu University of Architecture, which is located in a cold region, as an example, a field measurement analysis was conducted on the recessed balconies within the dormitory. The measured data were analyzed and utilized to simulate the annual energy consumption, thermal comfort predicted mean vote (PMV), and useful daylight illuminance (UDI) values of the dormitory units using the Grasshopper platform with the Ladybug and Honeybee plugins. The different depths of the balconies and window-to-wall ratios have a significant impact on the indoor physical environment and energy consumption, leading to the design of independent variables and the construction of a simplified parametric model. The simulation results underwent multi-objective optimization using genetic algorithm theory through the Octopus platform, resulting in a Pareto optimal solution set. Comparisons between the final-generation data and simulations of the original Song II dormitory unit indicate potential energy savings of up to 2.5%, with a 25% improvement in indoor thermal comfort satisfaction. Although there was no significant improvement in the UDI value, all the solution sets meet the minimum requirement of 300 lux specified by relevant regulations, according to the simulated average illuminance levels on the indoor work plane. Finally, the 60 optimal solution sets were further screened, filtering out sets deviating excessively from certain objectives, to identify 6 optimal solutions that are more balanced and exhibit a higher overall optimization rate. These findings offer detailed data references to assist in the design of dormitory buildings in cold regions.

Impact of different receiver geometries on a reconfigurable intelligent surface assisted multi-cell VLC system in the presence of light path blockage.

We report the effect of integrating metasurface-aided reconfigurable intelligent surfaces (RISs) on the signal-to-interference-plus-noise ratio (SINR) and data rate of a multi-cell visible light communication (VLC) system. RIS has been deployed in the channel between transmitter and receiver to redirect the reflected light in the desired directions, even in the absence of line-of-sight (LoS) links. Results show that the introduction of RIS has improved average SINR but reduced average illumination level compared to a no-RIS system. As the quantity of RIS increases, a discernible improvement in the maximum SINR value is observed. Here, three different receiver geometries, namely, a photodiode (PD), freeform diversity receiver (FDR), and modified FDR (MFDR), have been adopted. The impact of individual receivers has been reported in the presence of light path blockage. MFDR geometry is found to be most suitable with more coverage probability compared to the other two receivers. With (40c m×24c m) RIS area, during blockage, MFDR maintains an average SINR of 21.95dB, which is 97.29% and 14.24% greater than PD and FDR, respectively.

Daylighting Simulation for Sustainable Certified Building - Tokyo Global Square, Minato City, Japan

According to the World Green Building Council, Sustainable Building or Green building refers to a building that, in its design, construction, or operation, minimises or eliminates negative impacts on the climate and natural environment while also creating positive impacts and improving our quality of life. It aims to conserve natural resources. This study focuses on assessing the effectiveness of daylighting in enhancing the overall efficiency of an office building. The selected office building, Tokyo Toranomon Global Square, located in Minato City, Tokyo, Japan, is certified by LEED and has received sustainable ratings. LightStanza has been utilised as a daylighting simulation tool for this study. The findings reveal that several factors influence the efficiency of the space, including building orientation, window type, glass type, facade materials, and room depth. Through computer simulations, it has been determined that the average illuminance level of daylight entering the building meets the ideal illuminance values specified by specific organisations that provide criteria for optimal lighting in office working spaces, namely as the Japanese Industrial Standard, (JIS Z 9110, 2010 – General rules of recommended Lighting Levels).

Experimental study of a vertically mounted bifacial photovoltaic sunshade

BIPV (building-integrated photovoltaic) technology can convert incident solar energy directly into electricity while reducing cooling energy consumption. Using PV modules as a sunshade also prevents glare. Recently, the application of bifacial photovoltaic technology in the building sector has shown promise for achieving building energy-saving and carbon-neutral goals. In this study, we conducted an experiment to evaluate the thermal, light, and electrical performance of a vertically mounted bifacial photovoltaic sunshade (BiPVS). Over three consecutive days, the average daily power generation was 709.4 kJ for the west-oriented PV module and 636.7 kJ for the east-oriented one. The average electrical efficiencies were 15.67 % and 25.62 %. By applying BiPVS, the daily average illuminance levels were reduced by 2.48–4.64 % for the measurement point at 1.0 m distance from the window and 12.32–12.40 % for the point at 2.0 m distance. Additionally, we suggested two improvement solutions, including reserving intervals between the PV module and the window to facilitate natural convective heat dissipation and enlarging the height of the BiPVS. The results of this study demonstrate the energy-saving potential of the innovative BiPVS in low-carbon or zero-carbon building designs, and provide new ideas for the development of solar building integrated technology.

Natural lighting optimization through configuration of shading device for library in East Jakarta

Visual comfort is an important thing to consider in designing a library. The quality of lighting in reading rooms in public libraries in Jakarta is still below the SNI lighting standard of 300 lux. This study will discuss about optimizing and utilizing natural lighting for the reading room by using a combination of several types of shading devices. The method used is performing simulations and comparisons. A total of 138 types of shading devices were simulated with the VELUX Daylight Visualizer software and compared to find the best results. The results of the comparative analysis show that the GH1-19 shading device provides the most optimal results with an average illumination level of 548 lux and a uniformity ratio of 0.81 simulated in different seasons, times, and orientations.

Analysis of the relationship between nighttime illuminance and fear of crime using a quasi-controlled experiment with recorded virtual reality

By employing a quasi-controlled experiment with recorded virtual reality (VR), this study examines the impact of nighttime illuminance on fear of crime in four narrow streets without sidewalks in Seoul, South Korea. In April 2021, the horizontal and vertical illuminance of four streets was measured at 13 different time slots between 6 pm and 11 pm, and immediately afterward, the environment of the streets was recorded with a 360-degree camera. 101 young adult participants were asked to answer the level of fear of crime perceived in each video while experiencing 10 randomly selected VR videos out of 40 using head-mounted display. The results of the cross-classified multilevel analysis show that fear of crime can be reduced not only by enhancing average and minimum horizontal and vertical illuminance levels but also by improving the uniformity ratio of illuminance. In addition, the results are more evident in the video taken in the residential areas (Sites A and B) than in the commercial areas (Sites C and D). These results could be applied to nighttime illuminance management in narrow urban streets.

The effects of lamp types and surface reflectance combinations on the subjective perception of a simulated lit hospital ward environment

PurposeGood illumination creates an aesthetic environment that may positively influence patients’ well-being and provide comfort to the hospital staff. This study aims to focus on exploring the energy efficiency of lighting and subjective perception of the lit environment in a hospital ward to assess quality indicators of ambient lighting conditions.Design/methodology/approachThe existing conventional tubular fluorescent lamp–based lighting system in the surveyed patients’ ward was retrofitted with light-emitting diode (LED) luminaires to explore illumination and energy parameters. Thereafter, a software lighting model was created, simulated and analyzed. A Web-based survey with five bipolar adjective pairs in a semantic differential scale was conducted with 48 participants to record and analyze their subjective responses pertaining to the variations in lamp types and surface reflectance combinations.FindingsThe findings imply that the LED tubular lamp–based illumination was deemed more adequate compared to other lamp types and the effects of variations in room surface reflectance combinations on the participants’ responses were statistically significant at α = 0.05 level. The simulated horizontal work plane average illuminance level varied from 131 to 171 lx, mean room surface exitance (MRSE) levels remained between 30 and 90 lm/m2 and overall uniformity of illuminance remained between 0.5 and 0.7.Originality/valueIn a hospital ward illuminated by LED tubular lamps, variations in room surface reflectance combinations for a constant luminous flux package output from the lamps may affect the subjective perception of users and the correlation between horizontal work plane average illuminance and MRSE is found to be highly linear (coefficient of determination > 0.97).

ANALYSIS OF THE ILLUMINANCE LEVEL IN A CLASSROOM FOR DIFFERNT SKY CONDITION

Nowadays, due to the decrease in renewable energy sources on a global scale, studies for the effective use of energy and reducing energy consumption gain importance. Buildings have an extremely important role in energy consumption. Educational buildings, which are used for educational purposes, are important in terms of both the duration of use and the comfort level of the user. While the aim in educational institutions is to increase the level of user comfort, the main target is to increase the efficiency in educational activities. In energy consumption, the rate of consumption due to lighting is quite high. For this reason, effective and appropriate design of natural and artificial lighting is important in terms of both user efficiency and minimizing energy consumption. In lighting design, natural and artificial lighting should be considered in an integrated manner. The design should be started by considering daylight as the primary energy source. The homogeneous distribution of light in the space is as important as the average illumination level in the classroom. The light should spread homogeneously in the space in a way that provides equal efficiency to every user. In this study, the illuminance level of a selected classroom in Niğde Ömer Halisdemir University Faculty of Architecture was analyzed. In the selected workshop, measurements were made in the 5 weeks selected in November and December, at different times of the day and in different sky conditions, when the artificial lighting elements were on and off. In the case of the lamp on, generally sufficient average illuminance level can be met in all measurement hours, while it has been observed that sufficient average illuminance level is provided by turning on the lamps in the cloudy sky condition.

Integration of Horizontal Light Pipe and Shading Systems in Office Building in the Tropics

ABSTRACT Many high-rise office buildings in the tropics have a full-glazed facade and a deep open-plan space. Without any external shading, the office space has a non-uniform daylight distribution and glare problem. A deep open-plan space design also causes insufficient daylight levels in the area distant from the building perimeter. Previous studies about Horizontal Light Pipe (HLP) mainly focused on system improvement in capturing, transporting, and distributing daylight into deep space. Integration of HLP as a light transport system that can deliver daylight deeper into building interiors and shading systems consist of Light Shelf (LS), blinds that can redirect and reduce the excessive daylight level near the side window are proposed and studied. The research objective is to explain the daylight performance of the integration of HLP and shading systems. The research method is experimental with Radiance-based simulation as a tool. Surabaya (latitude 7.38° S and longitude 112.79° E), a typical city in the Tropics, was chosen for the simulation. Daylight level, daylight distribution, and Daylight Glare Probability (DGP) of office room with East-facing window are compared with office room with HLP and shading systems. The results showed that the integration of HLP and shading systems increased the average illuminance level in the deep area reached 135 % and reduced the average illuminance level in the area near the side window reached 55 %. HLP and shading systems also increase the daylight distribution inside space and slightly improve the DGP but still in the range of imperceptible for building users.

Illuminance Level Measurement at Lower Working Plane Height in Islamic Religious School

Islamic religious school is an institution that integrates Quran hafazan (memorization) in the curriculum. Between 2011 to 2017, estimated that 900 new Islamic religious schools were established in Malaysia due to high demands. Designing a classroom layout that receives sufficient daylight is important because it influences the students’ task performance such as reading and writing. The standards recommend that any classrooms require an illuminance level between 300 lx to 500 lx when measured at working plane height between 800mm to 900mm, although the working plane height of rehal used for hafazan is between 250mm to 300mm. This study focused on the illuminance level measured at rehal working plane height for Arabic handwriting as a hafazan learning task in two selected standardised classrooms at Kolej Genius Insan. The students were required to rewrite the modified Balsam Alabdulkader-Leat (BAL) Arabic eye chart, where the students’ Arabic handwriting performance were evaluated based on their word per minute (wpm) scores. Both classrooms’ average illuminance level were 507 lx to 603 lx, which were too high based on standards and guidelines. The average Arabic handwriting scores for both classrooms were 9.4 and 12.6 wpm, which shows that the inefficient average illuminance level has caused the students’ performance to be very low. It can be concluded that the existing standardised classroom layout design was not suitable for hafazan learning tasks at rehal working plane height. Thus, the classroom layout design for Islamic religious schools needed further studies, which implicated the unsatisfied built environment of the classrooms and the school education for Islamic religious schools in Malaysia.
 Keywords: Arabic handwriting, Daylighting, Illuminance level, rehal, working plane

Illuminance levels based on different sky conditions by considering daylight harvesting

Daylight Harvesting Systems (DHS) offer the most effective and significant to reduce energy consumption. In the lighting system, there are various problems which include waste of energy consumption, inappropriate lighting and increasing greenhouse effect. Therefore, the waste of energy consumption should be reduced by controlling the dimming levels of artificial lighting according to the standard thus reducing the greenhouse effect. Hence, this paper considered the daylight adaptive for the lighting system to determine the dimming level and illuminance level for the office room. The simulation has been carried out using DIALux simulation lighting software to simulate the average daylight and average illuminance level with different conditions sky, which is clear, average, and overcast sky. Based on the result, the illuminance level has complied with the European Standard EN12464-1. Furthermore, the presence of daylight and weather conditions plays an essential role in the lighting system. The illuminance and dimming levels are different depending on the time and type of sky condition at that time. Therefore, the daylight adaptive in the lighting system can reduce the use of artificial light in the room.

A new optimal light sensor placement method of an indoor lighting control system for improving energy performance and visual comfort

Lighting consumes a substantial amount of energy in buildings. Therefore, the energy can be potentially reduced by implementing optimal control strategies, including an optimal light sensor placement and an intelligent control. This paper presents a new optimal light sensor placement method (OLSPM) of a lighting system in terms of numbers and positions to minimize costs (i.e., initial and energy), and simultaneously maintain the visual comfort that satisfies the standard EN12464-1 in terms of illuminance-based metrics. The optimum position of the sensors was determined based on a proposed mathematical model, which is illuminance center grid, and then, an objective function and its constraints were formulated: average dimming levels of LED luminaires, and illuminance level and uniformity, respectively. Moreover, a new dimming level of luminaires model was proposed to calculate the objective function. Particle swarm optimization (PSO) algorithm was utilized for solving the formulated problem. Finally, the optimum position of the sensors was determined based on the PSO results and the proposed illuminance deviation model. This methodology denoted OLSPM-PSO. The OLSPM-PSO was tested on two case studies: a meeting room and an office room. To evaluate the performance of the OLSPM-PSO with other methods, the OLSPM-PSO was integrated with the developed fuzzy logic controller as a control strategy. The comparative results showed the superiority of the OLSPM-PSO with provided optimum number and position of sensors, significant energy savings up to 24.5% and fully satisfied visual comfort in accordance with EN12464-1 (i.e., average illuminance level and uniformity) and confirmed its potential to be implemented for all types of rooms with higher accuracy.

A study of luminous environment with prism daylight redirecting fenestrations in classrooms

This study explored the classroom luminous environment with prism daylight redirecting fenestrations. The differences between the International Commission on Illumination standard sky and the Perez all-weather sky models were analysed. The study described the method of generating a valid bi-directional scattering distribution functions .xml data for the prism daylight redirecting fenestrations. A new evaluation metric, daylight evenness, was proposed to describe indoor illuminance dispersion. Radiance simulation results indicate that at various solar altitude angles, compared with conventional glazing, the micro-prism film and micro-prism with an added diffuse layer on clerestories can improve the space average illuminance levels 23.2% and 18.7% under the International Commission on Illumination sky, as well as 15.4% and 10.6% under the Perez sky, respectively. The analysis results indicate that prism daylight redirecting fenestrations clerestories can improve indoor illuminance uniformity and daylight evenness when the solar altitudes range from 23.8° to 75°. A method combined field questionnaire and high dynamic range image analysis were conducted for discomfort glare study. Adding a diffused layer to the prism film clerestory is expected to alleviate discomfort glare for east- and west-facing prism daylight redirecting fenestrations clerestory with the daylight glare probability reduction of 3.8% to 21.7% at various solar altitudes. The research results present promising advantages of applying prism daylight redirecting fenestrations at classroom clerestories to improve the daylight luminous environment.

Energy-Saving Potential of Daylighting in the Atria of Colleges in Najran University, Saudi Arabia

Daylighting is recognised as an effective strategy for enhancing visual comfort and reducing energy used for electric lighting. Najran University, Saudi Arabia, has 15 colleges for males and 10 colleges for females. Each college has several atria and courtyards for introducing daylighting into the hearts of college buildings. However, the electrical lights used in the colleges atria and linked corridors keep on all the daytime. This study is an attempt to investigate the daylight illuminance level and energy-saving potential on the atria and linked corridors when it incorporates a time-scheduling lighting control system. The field measurements were performed in the College of Applied Medical Sciences. The results indicate that daylight illuminance in the atrium spaces are abundant with an average illumination level on the atrium floor varying from 300 lux to 3 600 lux, depending on the time of the day. In the clear sky climate of Najran city throughout the year, the time-scheduling control system is effective and found to contribute to approximately 43 855.2 kWh of annual energy savings in electrical-lighting consumption in the present case study scenario. The total annual energy savings from all 25 colleges at Najran University is 1 096 380 kWh/year, which results in a cost saving of approximately 93,512.86 USD. There would be additional substantial savings from other atria and courtyards in all of the college buildings throughout the campus

Effects of Lighting Quality on Working Efficiency of Workers in Office Building in Tanzania.

Background In this era of Information Communication Technology, a high-quality working environment is essential to the occupants. Providing quantity rather the quality of work environments is very common in most of the least developed countries, including Tanzania. Existing research asserts that poor indoor environmental quality such as lighting has a detrimental effect on human health, and in case of the office working population, it also affects their work performance. This study aims to analyze the effects of the lighting quality on working efficiency of workers in Tanzania. Methods Four representative offices from the administration building at Mbeya University of Science and Technology were investigated from June to September 2018. The customized questionnaire survey tool was administered to the randomly selected occupants to survey their perceptions about the quality of lighting in their workplace and its influence on their health and work efficiency. Physical observation and illuminance distribution measurements were also conducted. Results The statistical analysis indicates that the majority of the occupants are less satisfied with the lighting quality in their working environment, and some respondents reported that it significantly affected their work efficiency and wellbeing. The average desk illuminance and uniformity level were found to be below the recommended values of the Chartered Institution of Building Services Engineers (CIBSE) and the International Commission on lighting (CIE). Conclusion Despite the suggested improvement measures, this research emphasizes that poorly articulated work environment can adversely affect the productivity and work efficiency of the workers. The workers in such condition are also exposed to occupational diseases. Thus, providing a healthy work environment should be a fundamental right of the workers.

Design of an optical attocells configuration for an indoor visible light communications system

Visible light communications (VLC) is deemed as a promising technology for future indoor cellular communications due to its unique features, namely unlicensed free spectrum, high bandwidth, high security, and low power consumption. A small base stations (BS) called optical attocells are mounted on the ceiling of the room to provide communication and illumination simultaneously. In this paper, an optical attocells configuration model is proposed with the aim of providing a uniform illumination distribution while the field of view (FOV) is optimized to increase the receiver gain, furthermore, improving the received power and SNR distribution. The average illumination level of 635.6113 Lx is obtained, besides that, the minimum received power is improved from −2.17 to −1.286 dBm as compared with the previous studies. The proposed optical attocells model has used small number of LEDs chips, and hence, a reduction in link power consumption by 30.6% is achieved. Also, it was resolved the blind area at the centre of the room, and the total received power at the centre is improved from 3.2 to 5.967 dBm.

Multi-cell VLC system design under illumination and communication constraints

Visible Light Communication (VLC) uses lamps light to convey information. As such, lamps in VLC systems work not only as illumination devices, but as VLC Access Points (VAPs) as well. This makes the choice of the lamps’ specifications and positions vital to satisfy the illumination and communication requirements. It is important that an indoor environment has the best possible VLC performance and the lowest possible power consumption while maintaining satisfactory illumination conditions. Designing multi-VAP systems is challenging due to the conflicting requirements of illumination and communication. For example, closely installed lamps give more consistent illumination but more inter-VAP interference, and vice versa. In this paper, we propose an optimal strategy to design multi-VAP systems. We consider the general design problem that aims to maximize the VLC performance while minimizing the total power consumption. This should be achieved while keeping satisfactory illumination conditions represented by the average illumination level and the degree of illumination consistency. The multi-VAP system design is formulated as a two objective design problem with constraints on illumination. The interplay between the system design parameters and the constraints and objectives is then studied. Finally, the algorithm to optimize multi-VAP design strategies is proposed.

Down-link performance of an LED based visible light communication system through dynamic control of semi-angle

This paper analyzes the performance of the LED placement strategies based on different geometrical shapes for a pre-determined average bit error ratio. The optimally designed LED patterns have been investigated to understand the system’s energy efficiency in the full receiver mobility scenario for an indoor mobile visible light communication (VLC) system. Further, the system outage has also been analyzed for a moving receiver along with the characterization of root mean square (RMS) delay. Consequently, the bit rate of the transmission for the LED based design models has also been compared so as to employ the best mechanism for the purpose of network deployment. The investigation reveals that an appropriate choice of LED design strategy coupled with the right selection of LED semi-angle can improve the performance of various communication parameters including the overall transmitted power, number of LEDs used for full indoor mobility, average data throughput and illuminance level etc.

Assessment of building façade performance in-terms of daylighting and associated energy consumption in architectural spaces

This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain.Keywords: Shading device, Daylight Illuminance, Heat gain, Computer simulation, Energy consumption