scholarly journals Subjective assessment of visual comfort in a daylit workplace with an electrochromic glazed façade

2021 ◽  
Vol 2042 (1) ◽  
pp. 012179
Author(s):  
S Jain ◽  
C Karmann ◽  
J Wienold
Keyword(s):  
Subjective Assessment ◽  
Outdoor Environment ◽  
Field Of View ◽  
The Sun ◽  
Visual Comfort ◽  
Colour Perception ◽  
Building Facades ◽  
Glazed Facade ◽  
Shading Device ◽  
User Assessment

Abstract Electrochromic (EC) glazing is increasingly employed in building façades to achieve better visual comfort for the occupants. EC glazing can modulate the light entering through the façade by varying the solar transmittance of the glass and therefore can work as a shading strategy to minimize solar heat gains or glare. However, it also alters the spectrum and distribution of light entering through the façade, which influences certain visual attributes associated with a space. This user assessment study evaluates some of these attributes including the colour perception of the elements inside and outside the room, the uniformity of daylight distribution, the clarity of the view through the glazing and the perception of glare when the sun is in the field of view. Results indicate a visual transmittance (τv) of 0.6% is sufficient to control glare when the sun is in the peripheral field of view (FOV) while τv,n-n of 0.14% is required to control glare when the sun is close to the central FOV. Most of the participants did not perceive the colours of outdoor environment as natural when seen through EC glazed window. The majority of participants also desired to change the glazing configuration by adding an additional shading device.

Research on Physical MPPT of Photovoltaic Array System Based on Image Processing

2013 ◽  
Vol 321-324 ◽  
pp. 1138-1144
Author(s):  
Chao Liu ◽  
Jing Hui
Keyword(s):  
Image Processing ◽  
Tracking Error ◽  
Elevation Angle ◽  
Image Sensor ◽  
Azimuth Angle ◽  
Field Of View ◽  
The Sun ◽  
Photovoltaic Array ◽  
Point Tracking ◽  
Power Point

Based on analyzing the development and the performance feature of existing solar tracker, we propose a solar Maximum Power Point Tracking (MPPT) strategy which combines photoelectric sensor and image processing. Firstly, photoelectric tracking mode positions the sun in the field of view of the image sensor. Then, the position of the sun image is captured by the image sensor. After that, we can find the coordinates of the sun spot in the field of view through image binarization processing. According to the number of steps of stepper motor rotation which is calculated by the deviation of coordinates, the controller drives the biaxial photosensitive (PV) array tracking device, making the sun spot always fall in the centre of the image. Tests show that the elevation angle and azimuth angle of the tracking range of the photovoltaic array are both 0～270°.The average tracking error of elevation angle is less than 0.7°, and the average tracking error of azimuth angle is less than 0.5°.

Effects of Indoor Lighting on Occupants’ Visual Comfort and Eye Health in a Green Building

2010 ◽  
Vol 20 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Taeyon Hwang ◽  
Jeong Tai Kim
Keyword(s):  
Psychological Health ◽  
Green Building ◽  
Personal Characteristics ◽  
Visual Display ◽  
Visual Comfort ◽  
Visual Display Terminal ◽  
Eye Health ◽  
Shading Devices ◽  
Shading Device ◽  
Indoor Lighting

This study investigated the effects of indoor lighting on occupants’ visual comfort and eye health and to contribute to the management and maintenance of buildings. The illuminance of the working plane and windows at Samsung Corporation Headquarters were measured, and 2744 healthy occupants of Samsung Corporation were surveyed regarding the indoor lighting environment via the company’s intranet for 1½ years. This building was certified with the highest ranking by Korea’s Green Building Council. The cumulative data reflected the management and maintenance of the building, such as screen-type shading devices automatically controlled by seasons and time, improvement of visual display terminal glare by the veiling reflection on monitors, efficiency of artificial lighting arrays, and so on. The data were analysed for occupants’ visual comfort and eye health. The result showed that daylighting could improve the occupants’ psychological health and productivity. The screen-type shading device could intercept direct sunlight and reduce annoyance glare. However, the indoor lighting and visual environment of the building were poor. After examining the questionnaire feedback concerning improvements, the occupants’ annoyance ratio was significantly reduced, and approximately 5% of the occupants’ annoyance ratio was deemed to be caused by personal characteristics related to the lighting of the environment.

A Guidance System for Aiming a Spectrometer Field of View at the Sun

2018 ◽  
Vol 61 (6) ◽  
pp. 869-872
Author(s):  
B. E. Moshkin ◽  
A. V. Zharkov ◽  
I. A. Maslov ◽  
O. V. Sazonov
Keyword(s):  
Field Of View ◽  
Guidance System ◽  
The Sun

Roller blinds characterization assessing discomfort glare, view outside and useful daylight illuminance with the sun in the field of view

Solar Energy ◽  
2021 ◽  
Vol 213 ◽  
pp. 91-101
Author(s):  
Julieta Yamín Garretón ◽  
Ayelén María Villalba ◽  
Roberto Germán Rodriguez ◽  
Andrea Pattini
Keyword(s):  
Field Of View ◽  
The Sun ◽  
Discomfort Glare

scholarly journals Optimization of Design and Planing VHS Building Using Chronolux

2016 ◽  
Vol 1 (2) ◽  
pp. 170
Author(s):  
Beta Paramita ◽  
Ismahnida Kamilia ◽  
Muhammad Iqbal Nurhidayat ◽  
Resty Ocktaviyane
Keyword(s):  
Food Service ◽  
Sun Exposure ◽  
Family Welfare ◽  
The Sun ◽  
Vocational High School ◽  
Design Strategies ◽  
Planning And Design ◽  
Building Facades ◽  
Site Planning ◽  
Building Engineering

Gedebage integrated vocational high school (SMK) is a school which accommodates the concept of technopolis. The school has four programs: building engineering, family welfare education (PKK/food service), mechanical engineering, and tourism - which produce skilled and ready-to-work graduates. This article aims to recommend the sun exposure toward the building of the school, which is related to site planning and design strategies based on the duration of solar radiation on vegetation, and building facades as well as the distance between buildings through the use of Chronolux plug-in on Sketch-up Software. From the measurement, it is found that vegetation can reduce sky view factors (SVF) from 76.4 to 38.87%. For the building façade, it is able to reduce sun exposure from 4 hours 51 minutes to 3 hours 19 minutes with SVF from 47.26 to 38.11%. Meanwhile, the building distance of 9 m receives sun exposure from 9:00 am to 3.42 pm.

scholarly journals Optimization of Building Façade to Control Daylight Excessiveness and View to Outside

2019 ◽  
Vol 9 (2) ◽  
pp. 161-168
Author(s):  
P. Nadiri ◽  
M. Mahdavinejad ◽  
P. Pilechiha
Keyword(s):  
Significant Role ◽  
Sun Exposure ◽  
Optimization Process ◽  
Visual Comfort ◽  
The South ◽  
Interior Spaces ◽  
Building Facade ◽  
Building Facades ◽  
Reasonable Range ◽  
Shading Devices

Abstract Windows and shading devices play a significant role in designing building facades to control the rate of the received daylight and improve visual comfort. This study is aimed to provide an optimization basis for building’s façade considering two variables of Annual Sun Exposure (ASE (1000/250h)) and the view to outside of an office. In this research, the effect of various parameters of shading louvers to the south was investigated in Tehran, Iran. The parameters were number, depth, angle as well as thickness. In this review, Rhino/Grasshopper plug was employed for simulations; moreover, Galapagos evolutionary solver component was used to run the optimization process. This study’s findings showed that it was possible to reach a view of nearly 90% of the interior spaces while the value of ASE (1000/250h) still remained in the reasonable range.

Development of a Computer Model for Solar Simulation and Shaded Fenestration Design

2001 ◽  
Author(s):  
John Kie-Whan Oh ◽  
Jeffrey S. Haberl ◽  
Larry O. Degelman
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Computer Model ◽  
Thermal Performance ◽  
Energy Efficient ◽  
Design System ◽  
The Sun ◽  
Physical Test ◽  
Shading Device ◽  
Solar Simulation

Abstract The goal of this study was to develop a computer model for solar radiation calculation and display and a shaded fenestration design system that can be used by architectural and engineering designers. This computerized model calculates the amount of insolation and transmitted solar radiation through a shaded window as well as the heat transfer through it. The computer model, called Shaded Fenestration Design (SFD), contains various functions relating to solar simulation such as: display of the sunpath diagrams and the accompanying shading mask protractor, display of the hourly intensity of solar radiation onto the path of the sun for horizontal and vertical surfaces at varying off-south azimuths, and simulating the thermal performance of a shaded fenestration. The model also provides graphical aids for energy-efficient shading device design with use of various kinds of sunpath diagrams and solar radiation diagrams. The model performs solar radiation simulation using the methods developed in the ASHRAE Handbook, Duffie and Beckman, and Kreider and Rabl. An anisotrophic sky model was applied for the calculation of solar radiation on a titled surface and the transmitted solar radiation through a single-glazed window. A part of the model was validated experimentally using a physical test box and was also compared to simulated results from the DOE-2 program; however, the validation is not included in this paper.

scholarly journals Chromogenic Technologies for Energy Saving

2020 ◽  
Vol 2 (4) ◽  
pp. 462-475
Author(s):  
Alessandro Cannavale
Keyword(s):  
Energy Consumption ◽  
Energy Balance ◽  
Spectral Properties ◽  
Scientific Literature ◽  
Visual Comfort ◽  
Artificial Lighting ◽  
Wide Range ◽  
Building Facades ◽  
Reduce Energy Consumption ◽  
External Stimuli

Chromogenic materials and devices include a wide range of technologies that are capable of changing their spectral properties according to specific external stimuli. Several studies have shown that chromogenics can be conveniently used in building façades in order to reduce energy consumption, with other significant effects. First of all, chromogenics influence the annual energy balance of a building, achieving significant reductions in consumption for HVAC and artificial lighting. In addition, these technologies potentially improve the indoor level of visual comfort, reducing the risks of glare and excessive lighting. This brief review points to a systematic discussion—although not exhaustive and mainly limited to recent results and investigations—of the main studies that deal with building-integrated chromogenics that have appeared, so far, in the scientific literature.

scholarly journals IR Observations of the K and F Corona During the 1991 Eclipse

1994 ◽  
Vol 154 ◽  
pp. 185-197 ◽  
Author(s):  
J. R. Kuhn ◽  
H. Lin ◽  
P. Lamy ◽  
S. Koutchmy ◽  
R. N. Smartt
Keyword(s):  
High Altitude ◽  
Surface Brightness ◽  
Field Of View ◽  
Array Detector ◽  
The Sun ◽  
Polarization Data ◽  
Array Detectors ◽  
Western Side ◽  
Local Dust ◽  
K Band

The availability of relatively large format IR array detectors is incentive for reexamining the classic question of whether or not there are “dust rings” around the sun – a problem for which there are conflicting observational answers. The 1991 eclipse path included a high altitude observatory and provided a potentially ideal opportunity to study the infrared properties and dust content of the corona. Here we report results from an experiment conducted from Mauna Kea using a HgCdTe array detector sensitive to wavelengths between 1-2.5 μm. Surface brightness measurements in the H-band and polarization data in the J-band were obtained over a field-of-view of ±6 R⊙ while K-band images further extend to 15 R⊙ on the western side of the Sun. J-band polarization data and H and K-band surface brightness data clearly show the inhomogeneous structure in the K corona and the ecliptical flattening of the F corona. We see no evidence of a circumsolar, local dust corona (dust rings) out to 15 R⊙.

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