Study of effect of daylight on Building User's Performance Based on Electroencephalograph Signal

The use of daylighting in building nowadays has become one alternative to save electric energy consumption, particularly during daytime. Daylight is not only useful for reducing cost from electric light sources, but also give benefits both physiologically and psychologically for building users. Studies in various countries showed that daylight was more preferable as main light source, compared to light from electric lamps. Effect of daylight on performance of building users might be evaluated based on variation of electroencephalograph (EEG) signal, specifically alpha and beta waves. In this research, EEG signal was used to evaluate brain response of the participant while doing activity of solving jigsaw puzzle under daylight condition inside a room. Several factors were varied, i.e. average illuminance on work plane (1000 and 300 lux), orientation of the participant with regard to the window (perpendicular and parallel to the window plane), and timing of the experiments (at noon [12.00~13.00 WIB] and in the afternoon [14.30~15.30 WIB]). The measured EEG signal was then analyzed using power spectral density (PSD), to determine the alpha and beta waves. From the experiments result, it was proven that EEG signal variation had existed, based on electrode locations and lighting quality factors, i.e. average illuminance on work plane and timing. On primary visual cortex, average of beta waves increased, relative to idle condition. Combination of 1000 lux, perpendicular, noon was found to increase the participant’s performance at most, as well as beta waves. Combination of 1000 lux, noon was found to increase alpha waves at most, resulted in relax and calm condition, even though the participant was doing physical activity. Generally, daylight and fluorescent lamp light did not give any significant difference

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)

Lighting Design for Axis of Gedung Sate and Monument of West Java People's Struggle

Bandung is a historical city which inherits many architectural heritages, including Gedung Sate as the office for West Java Governor. Development of Gedung Sate area are moving from widening the building’s wings, the Gazebo field, up to the Monument of West Java People’s Struggle; altogether in one axis toward Mount Tangkuban Parahu to become an urban icon in Bandung. As monumental buildings and landscape, proper lighting design concept is required in order to support visual performance and comfort around the area during nighttime. In this research, field measurements were conducted to map the existing lighting condition around the axis of Gedung Sate - Monument of West Java People’s Struggle. Subjective opinions from people at the area were also submitted by questionnaires. These data were considered as input for designing the lighting concept. Some ideas applied to develop the most suitable lighting concept for the area are constructing the imaginary axis, by arranging lighting installment in a linear path from south to north. Light emmiting diodes (LED) will be used at most to achieve the needs for color effect, energy efficiency, as well as long lifetime. Some decorative road lamps and pathway lamps will use HIT type, while underwater lamps in pond area will use MR 16 type, combined with LED to get the desired effect of color changing. From questionnaires regarding the new lighting design concept, 95% felt satisfy with the simulation result and 80% agreed if the design is implemented at the site area

Evaluation on Lighting Condition and Visual Legibility of Road Surfaces and Traffic Signs in Bandung City

As the capital city of West Java Province, Bandung has been growing fast nowadays, which increases the number of road users, during day and nighttime. In order to assure road users can drive safely at nighttime, good visual condition of the road surfaces and their traffic signs is required. The main objective of this research is to evaluate lighting condition and visual legibility in some roadways in Bandung, by determining average luminance, overall uniformity, longitudinal uniformity, and luminance coefficient of road surfaces and traffic signs, and comparing with the minimum criteria. Software was used to simulate the lighting condition of the roadways and to optimize the lighting parameters. Laboratory experiments were conducted to investigate visual legibility of some common traffic signs, based on luminance contrast of the traffic signs’ material. Generally, lighting parameters of the observed roadways had not fulfilled the minimum standard recommended by the Illuminating Engineering Society of North America. Concrete surface was also found more reflective (average luminance coefficient of 0.05 cd/m2/lux) than asphalt one (0.04 cd/m2/lux). Laboratory results show that most traffic signs in Bandung were made of advertising grade material, whose average luminance contrast values ranged from 2.33 to 2.85, which were still below the American Association of State Highway and Transportation Officials M.268-77 standard which states traffic signs at least must be made of engineering grade material

Radiation modeling of a photo-reactor using a backward ray-tracing method : an insight into indoor photocatalytic oxidation

This article aims to understand the radiation behavior within a photo-reactor, following the ISO 22197-1:2007 standard. The RADIANCE lighting simulation tool, based on the backward ray-tracing modeling method, is employed for a numerical computation of the radiation field. The reflection of the glass cover in the photo-reactor and the test sample influence the amount of irradiance received by the test-sample surface in the photo-reactor setup. The reflection of a white sample limits the irradiance reduction by the glass cover to 1.4 %, but darker samples can lead to an overestimation up to 9.8 % when used in the same setup. This overestimation could introduce considerable error into the interpretation of experiments. Furthermore, this method demonstrates that the kinetics for indoor photocatalytic pollutant degradation can be refined through radiation modeling of the reactor setup. In addition, RADIANCE may aid in future modeling of the more complex indoor environment where radiation affects significantly photocatalytic activity

Simulation of virtual natural lighting solutions with a simplified view

Daylight is limited in time and space. In situations where daylight is insufficiently available, virtual natural lighting solutions (VNLS), which are systems that artificially provide lighting and view comparable to those of real windows and skylights, can be promising. VNLS can turn currently unused floor space into space with daylight qualities. The space-gaining potential of VNLS in buildings can be predicted using computational building performance simulation. This paper describes the approach of modelling VNLS with a simplified view, using the Radiance tool to evaluate the lighting performance in a reference office. The VNLS are modelled as arrays of small light sources resembling the sky, the horizon and the ground. The simulation results show that VNLS with wide beam angles generally offer a better uniformity and a larger percentage of sufficiently lit workplane area compared to those obtained with real windows under overcast sky conditions, while the discomfort glare remains comparable to that received from real windows

Modelling and simulation of virtual natural lighting solutions with complex views

In situations where daylight is insufficiently available, Virtual Natural Lighting Solutions (VNLS) can be promising to turn currently unused floor space into spaces with enough daylight qualities. This article introduces VNLS models with complex image scenes pasted on a transparent glass surface in front of arrays of small, directional white light sources. The objectives are twofold; the first one is to understand the effect of changing input variables, i.e. beam angle, total luminous flux of the 'sky' elements, and image scene itself; on the lighting performance of a reference office space. The second objective is to compare two techniques of modelling the view, i.e. transmissive and emissive approaches, using Radiance. Sensitivity analysis of the simulation results show that under every image scene, the total luminous flux of the 'sky' element is largely influential to the space availability, whereas the beam angle of the 'sky' element is largely influential to the other output variables, including discomfort glare. The findings lead to a suggestion of preferred elements in the image scene, to ensure large space availability and uniformity. The transmissive approach generally generates smaller values of space availability, and largely depends on the view elements of the image scene. In turn, the average probability of discomfort glare using the transmissive approach is smaller than that using the emissive approach

Review of Modelling Approaches for Developing Virtual Natural Lighting Solutions

Several studies have shown that natural light is preferred over electrical lighting in built environments. It has positive effects on user satisfaction, health, and energy saving. However, natural light is limited by time and space. A possible solution is to apply the new concept of virtual natural lighting solutions that ideally can artificially provide natural lighting and views, with all of their properties. Computational modelling has the potential to steer the innovation process and early feasibility testing of this solution. Several available modelling approaches are reviewed, examining their ability to predict performance indicators of the system, in terms of lighting, view, space availability, thermal comfort, and energy consumption