scholarly journals A Study on Daylight Control Method for Securing Visual Comfort and Reducing Lighting Loads on Interior Lighting Environment

2012 ◽  
Vol 32 (6) ◽  
pp. 100-105 ◽  
Author(s):  
Sang-Pil Han
Keyword(s):  
Control Method ◽  
Visual Comfort ◽  
Interior Lighting ◽  
Lighting Environment ◽  
Lighting Loads

The Field Office Survey for Lighting Environment in Taiwan

2014 ◽  
Vol 496-500 ◽  
pp. 2569-2574
Author(s):  
Yu Sen Lin ◽  
Takaaki Koga ◽  
Kotaroh Hirate ◽  
Yi Chun Kuo
Keyword(s):  
Energy Efficient ◽  
Electrical Energy ◽  
National Standards ◽  
Visual Comfort ◽  
Field Office ◽  
The World ◽  
Lighting Environment ◽  
Lighting Loads ◽  
Working Plan ◽  
Better Than

Lighting consumes approximately 24.8% of the electrical energy supplied to office buildings in Taiwan. Even if those estimations are difficult to verify and might not be completely consistent, these figures lead to one important finding: around the world, the scientific community seems to agree that discussing the article lighting loads of buildings is extremely important and that energy-efficient lighting solutions have to be adopted. In order to guarantee an appropriate visual comfort in office, the horizontal illumination (especially on the working plan) must be sufficiently enough. According to CIE, it is suggested in 200 lux to 500 lux in offices, and CNS (Chinese National Standards, Taiwan) is 500 lux in Taiwans offices. According to survey and questionnaire, 500lux maybe is too high for employee in Taiwan. When the illuminance is below 500lux, brightness and satisfaction is not bad, and when the illuminance is over 500lux, brightness and satisfaction is not better than low illuminance. Even if office is in high horizontal illuminance environment, employees brightness, satisfaction and productivity are not guaranteed.

Visual Comfort Control for Building Energy Management System

2012 ◽  
Vol 512-515 ◽  
pp. 2838-2841
Author(s):  
Shin Yen Lin ◽  
Wei Yuan Chen
Keyword(s):  
Energy Management ◽  
Control Algorithm ◽  
Control Method ◽  
Fuzzy Controller ◽  
Building Energy ◽  
Fine Tuning ◽  
Visual Comfort ◽  
Two Stage ◽  
Building Energy Management ◽  
Venetian Blind

In this paper, we propose a two-stage energy saving control algorithm to resolve the visual comfort control problem of building energy management systems (BEMS). The first stage control method consists of a fuzzy controller to control the venetian blind so as to exploit the outdoor luminance as much as possible while avoiding the sun glare. To remedy the possible imperfection caused by the fuzzy controller, a follow up fine tuning step is designed to adjust the outputs of the venetian blind resulted from the fuzzy controller. The second stage control is to determine whether to turn on the light based on the luminance measured by the sensor after the first stage control so as to save electricity. We have simulated the proposed two-stage control algorithm and demonstrate that the electricity saving can be up to 61% in the tested room.

A Simple Method to Improve VCP by Reducing DGR in an Interior Lighting Installation

2018 ◽  
pp. 73-81
Author(s):  
Madjidi Faramarz ◽  
Abedi Kamal ad-Din
Keyword(s):  
Surface Area ◽  
Main Role ◽  
Visual Comfort ◽  
Lighting System ◽  
Simple Method ◽  
Evaluation Systems ◽  
Interior Lighting ◽  
Modified Equations ◽  
Comfort Perception ◽  
Discomfort Glare

Discomfort glare rating (DGR) and Unified glare rating (UGR) are main models currently used as discomfort glare evaluation systems, both of which are calculated employing four factors including the luminaire size, the luminaire position relative to the observer, background luminance, and the luminaires number and location. This study aims at proposing a simple solution for reducing DGR and thereby increasing visual comfort perception (VCP) in an interior lighting system. The proposed solution is based solely on variations of luminaire surface area without change in other factors, e.g. candlepower and number and location of luminaires in the lighting system. To this end, firstly, the equations related to DGR were modified for a desired luminaire, and, secondly, by solving the modified equations, the new luminaire surface area was obtained, which caused DGR decrease and VCP improvement. Finally, by some modifications in the location of selected luminaires having main role on DGR, the VCP rose considerably.

scholarly journals Space of visual and circadian parameters of RGBW lighting systems

2020 ◽  
Vol 1 (57) ◽  
pp. 16-21
Author(s):  
D. Kalustova ◽  
V. Kornaga ◽  
A. Rybalochka ◽  
S. Valyukh
Keyword(s):  
Power Distribution ◽  
Spectral Power ◽  
Visual Comfort ◽  
White Leds ◽  
Spectral Power Distribution ◽  
Circadian Effect ◽  
Lighting Environment ◽  
Lighting Systems ◽  
Colour Rendering ◽  
Effect Of Light

Due to the proven effect of light on human circadian rhythms, nowadays researchers and developers of lighting systems (LS) concentrate on the non-visual parameters of light and methods of ensuring a safe comfortable light environment. This requires optimisation of spectral power distribution (SPD). In this view the most promising and functional are RGBW systems due to their ability to change dynamically SPD and, hence, light parameters. In this work we explore two RGBW (red-greenblue-white) systems with different white LEDs (warm white and neutral white) and the space of visual and non-visual parameters that they can ensure. Visual parameters are studied in terms of colour rendering index, colour fidelity index and visual corneal illuminance while non-visual parameters are studied in terms of circadian light, circadian stimulus and circadian action factor. These parameters are calculated for different contribution of the components in a correlated colour temperature (CCT) range of 2500 – 7000K. In addition, acceptable criterion of the colour fidelity index above 85 is used. It is shown that under this condition the circadian action factor in the range of 0.33-0.98 can be obtained by changing the CCT and (or) colour fidelity index. Also an achievable area of the circadian stimulus versus corneal illuminance space for RGBW systems is found. It enables to choose optimal combination of CCT, circadian stimulus and corneal illuminance to provide the desired level of circadian effect with sufficient visual comfort depending on the daytime and field of system's implementation. This data is useful for LS manufacturers and lighting designers to create a comfortable lighting environment. Keywords - RGBW colour mixing, tunable white light, circadian effect, colour rendering, colour fidelity index.

scholarly journals Performance Evaluation of Control Methods for PV-Integrated Shading Devices

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3171
Author(s):  
Sung Kwon Jung ◽  
Youngchul Kim ◽  
Jin Woo Moon
Keyword(s):  
Tilt Angle ◽  
Control Method ◽  
System Modeling ◽  
The Other ◽  
Control Methods ◽  
Visual Comfort ◽  
Ann Model ◽  
Indoor Space ◽  
Shading Devices ◽  
Shading Device

This study aimed to develop a building-integrated photovoltaic (BIPV) device and optimal control methods that increase the photovoltaic (PV) efficiency and visual comfort of the indoor space. A louver-type PV-integrated shading device was suggested and an artificial neural networks (ANN) model was developed to predict PV electricity output, work plane illuminance, and daylight glare index (DGI). The slat tilt angle of the shading device was controlled to maximize PV electricity output based on three different strategies: one without visual comfort constraints, and the other two with visual comfort constraints: work plane illuminance and DGI. Optimal tilt angle was calculated using predictions of the ANN. Experiments were conducted to verify the system modeling and to evaluate the performance of the shading device. Experiment results revealed that the ANN model successfully predicted the PV output, work plane illuminance, and DGI. The PV-integrated shading device was more efficient in producing electricity than the conventional wall-mount PV systems, the control method without visual comfort constraints was most efficient in generating electricity than the other two with such constraints, and excluding the constraints resulted in less comfortable visual environment and reduced energy benefit. From the results analysis, it can be concluded that based on the accurate predictions, the PV-integrated shading device controlled using the proposed methods produced more electricity compared to the wall-mount counterpart.

scholarly journals Evaluation of Building Energy and Daylight Performance of Electrochromic Glazing for Optimal Control in Three Different Climate Zones

2018 ◽  
Author(s):  
Myunghwan Oh ◽  
Minsu Jang ◽  
Jaesik Moon ◽  
Seungjun Roh
Keyword(s):  
Optimal Control ◽  
Solar Radiation ◽  
Control Method ◽  
Building Energy ◽  
Building Envelope ◽  
Glass Technology ◽  
Solar Radiation Incident ◽  
Optimal Control Method ◽  
Lighting Loads ◽  
Daylight Performance

Solar radiation is closely related to the energy buildings consume for cooling, heating, and lighting purposes. Glazing is the only material of the building envelope that transmits solar radiation and needs to be appropriately designed to reduce energy cㅈonsumption. Currently, smart glass technology is being actively investigated and developed for effective solar radiation control. Among the various types of smart glass, electrochromic glazing is one of the most promising technologies, as it can adjust transmittance on its own, has a wider transmittance range in both the clear and darkened states, and consumes less electricity. Considering the importance of solar radiation adjustment in electrochromic glazing technology, this study attempted to develop an optimal control method for electrochromic glazing. Toward this goal, the solar radiation incident on vertical surfaces and outdoor temperature conditions were controlled in three regions with different climatic characteristics, and the annual cooling, heating, and lighting loads, discomfort glare, and interior illumination were analyzed. This approach enabled the optimal conditions with respect to visual comfort to be determined. Subsequently, the EDPI (Energy and daylight performance index) was used to optimize control conditions for each region, thereby producing integrated evaluations from results with different units and properties. The proposed control method will be utilized to develop a control algorithm and a control system to reduce building energy consumption.

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