scholarly journals Preliminary Study on the Performance Evaluation of a Light Shelf Based on Reflector Curvature

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4295 ◽  
Author(s):  
Heangwoo Lee ◽  
Janghoo Seo ◽  
Chang-ho Choi
Keyword(s):  
Performance Evaluation ◽  
Energy Consumption ◽  
Natural Lighting ◽  
The Future ◽  
Lighting Energy ◽  
Effective System ◽  
Fixed Type ◽  
Preliminary Study ◽  
Reduce Energy Consumption ◽  
Lighting Systems

The consumption of lighting energy in buildings continues to rise, and many studies are being conducted to address this problem. As part of such initiatives, research is being performed on light shelves, which are natural lighting systems. However, most prior studies focused on variables for operating flat reflectors and light shelves. This study aims to evaluate the performance of curved light shelves to prove their effectiveness and derive optimal specifications for them. The following conclusions were reached. The optimal light shelf angles for a flat light shelf were found to be 30°, 20°, and 20° for the summer, mid-season, and winter, respectively, and accordingly, a movable light shelf system would be suitable for all three seasons. The optimal light shelf angles for a movable curved light shelf with an arc angle of 60° were found to be 30°, 30°, and 10° for the summer, mid-season, and winter, respectively. The optimal light shelf angle and arc angle for a fixed-type curved light shelf were found to be 20° and 60°, respectively. A fixed-type curved light shelf designed according to these optimal specifications can reduce energy consumption by 3.6% in comparison to a movable flat light shelf. Consequently, the curved light shelf is considered an effective system, and additional studies analyzing various other factors should be carried out in the future.

A Thermal Model of a Fiber Optic Bundle for a Hybrid Solar Lighting System

2005 ◽  
Author(s):  
Michael J. Cheadle ◽  
Gregory F. Nellis ◽  
Sanford A. Klein ◽  
William A. Beckman
Keyword(s):  
Energy Consumption ◽  
Thermal Model ◽  
Fiber Optic ◽  
Management Strategies ◽  
Design Tool ◽  
Lighting Energy ◽  
Solar Lighting ◽  
Reduce Energy Consumption ◽  
Lighting Systems ◽  
Cooling Loads

Hybrid solar lighting (HSL) systems distribute natural sunlight to luminaires located in office or retail buildings in order to reduce energy consumption associated with conventional lighting systems. HSL systems reduce energy consumption directly by reducing the lighting energy and indirectly by reducing the associated cooling loads. A key component of the HSL system is the fiber optic bundle (FOB) that transmits the light from the collector to the luminaire. The observed thermal failure of the FOB when exposed to concentrated sunlight has motivated the development of a thermal model of this component. This paper describes the development of a predictive thermal model of the heat transfer in an FOB for an HSL system. The model is verified experimentally against temperature measurements obtained in the lab under controlled conditions and provides a powerful design tool that can be used to evaluate alternative thermal management strategies.

Study on Determination of Best Window-Wall Ratio of Office Building in Cold Area

2012 ◽  
Vol 260-261 ◽  
pp. 209-216 ◽  
Author(s):  
Zhi Hua Zhou ◽  
Shan Hu ◽  
Tao Du
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Northern China ◽  
Office Building ◽  
Lighting Control ◽  
Natural Lighting ◽  
North East ◽  
Lighting Energy ◽  
Heating Load ◽  
Heating Energy Consumption

The cooling and heating load caused by the heat transfer of the window is significantly greater than that caused by the heat transfer of wall because of the large heat transfer coefficient of the window. At the same time, the sun radiate heat through the window into indoor can increase the cooling load and decrease the heating load; the natural lighting enhances, and the lighting energy consumption decreases because of entering sunlight. The paper took a low energy consumption office building in the northern China for example, synthetically analyzed the cooling energy consumption, heating energy consumption and lighting energy consumption of every orientation under the condition of lighting control or no lighting control. The results show that comparing with no lighting control, the energy consumption with lighting control is less. When using lighting control, the best WWR of south, north, east, west are 0.35, 0.3, 0.3, 0.25, respectively; then the building energy saving rate is 8.2%.

scholarly journals The identification of variables influencing personal lighting conditions of office workers

2020 ◽  
pp. 147715352097695
Author(s):  
J van Duijnhoven ◽  
MPJ Aarts ◽  
ER van den Heuvel ◽  
HSM Kort
Keyword(s):  
Energy Consumption ◽  
Mixed Models ◽  
Weather Conditions ◽  
Office Workers ◽  
Lighting Control ◽  
Know How ◽  
Lighting Conditions ◽  
Daily Schedule ◽  
Reduce Energy Consumption ◽  
Lighting Systems

The main reason lighting control is being applied is to reduce energy consumption. However, there are many more reasons for lighting control to be optimised in buildings. Lighting systems can be controlled to enhance or optimise effects beyond vision. Automatic control of electric lighting systems or daylight systems is one way of adjusting someone’s personal lighting conditions. In addition, it is relevant for office workers to know how they can adjust their personal lighting conditions themselves in order to optimise their effects beyond vision (e.g. alertness). Therefore, this article describes a process of identifying predictors that influence personal lighting conditions. The dataset used in this article is gathered during a field study in the Netherlands in spring 2017. This article describes linear mixed models for daily mean illuminances and correlated colour temperatures both throughout the entire day and only at work. These models demonstrated that weather conditions, fixed and flexible personal conditions, office worker’s daily schedule and workspace characteristics influence personal lighting conditions. Weather conditions and fixed and flexible personal conditions though are difficult or impossible to control by the office workers themselves. However, adjustments in personal lighting conditions can be accomplished by the office workers themselves by changing their daily schedules and the workspace characteristics. The findings show that these two predictor categories may explain 4% to 20% of the variance in personal lighting conditions.

Light Environment Research in the Patio of College Teaching Building - Tiangong Building in Hubei Engineering College for Example

2014 ◽  
Vol 507 ◽  
pp. 115-118
Author(s):  
Jie Tan ◽  
Wei Liu ◽  
Meng Lin Wang
Keyword(s):  
Energy Consumption ◽  
College Teaching ◽  
Electrical Energy ◽  
Maintenance Cost ◽  
Analysis Software ◽  
Curtain Wall ◽  
Actual Measurement ◽  
Natural Lighting ◽  
Reduce Energy Consumption ◽  
High Benefit

The college teaching building which corridor inside would be spend large quantities of electrical energy for the corridor lighting during the day, and although the teaching building of atriums could obtain good natural lighting and the atrium space, but due to the design of the glass curtain wall and glass ceiling large energy consumption, even with high technology , such as wind towers or daylighting shutter, to reduce energy consumption, but the investment and maintenance cost is large. Patio with its strong vitality of Chinese traditional local-style dwelling houses and unique charm come down, therefore, will raise a reasonable applied to the teaching building is a kind of low technology design to obtain high benefit .This article analys the apply of patio in teaching building, Hubei engineering college for example, using the analysis software and actual measurement, obtain the effect of natural lighting in the teaching building which the patio used and the influence of patio structure on natural lighting.

scholarly journals PENGARUH DESAIN COURTYARD TERHADAP KONSUMSI ENERGI UNTUK AC (AIR CONDITIONER) DAN PENCAHAYAAN (Studi Simulasi Hipotetik Bangunan Tinggi Perkantoran di Jakarta)

2018 ◽  
Vol 14 (1) ◽  
pp. 36-47
Author(s):  
Galih Gusti Yudha Saelendra ◽  
Jatmiko Adi Suryabrata ◽  
Dimas Wihardyanto
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Simulation Method ◽  
The Sun ◽  
Air Conditioner ◽  
Total Energy Consumption ◽  
Total Consumption ◽  
Natural Lighting ◽  
Lighting Energy ◽  
Glass Type

ABSTRACT Increasing the natural lighting can reduce the lighting energy consumption haw a weather but it can be potentially increasing the weather energy so there must be strategy needed to save the energy. That condition is the problem statement of this research, to know the configuration of the natural lighting and the effective cooling load. In this research, the simulation method with hypothetic building object has been used to test how big the influence of courtyard dimension, (Wall To Window Ratio) WWR and glass type towards the total consumption of energy for AC (Air Conditioner) and lighting. The result of this research is the most affective courtyard configuration is courtyard dimension 1, WWR 30 %, stopsol glass type. From the courtyard dimension variable, WWR and glass type, for the total energy consumption for AC and the highest lighting influenced its energy efficiency is clear glass type 15,56%, panashap glass 9,09%, WWR 70% 6,25%, WWR 50% 1,91%, courtyard dimension 2 0,27%, courtyard dimension 3 0,18%. In Jakarta with the tropical climate is not suitable to apply the courtyard application which is too big, it must be concerned the wide and high proposition so the total energy consumption for AC and lighting would not be so big. While the open orientation is not so influencing the sun radiation, so avoid the open part from east and west. For the WWR building range is between 50% - 70% must be paid attention in choosing the glass type because as small as the SC (Shading Coefficient) is lower the sun radiation. Keywords : AC (Air Conditioner), Courtyard, Glass type, Lighting, WWR. ABSTRAK Meningkatkan pencahayaan alami dapat mengurangi konsumsi energi pencahayaan namun, berpotensi meningkatkan energi penghawaan maka diperlukan strategi untuk penghematan energi. Kondisi tersebut yang menjadi permasalahan dalam kajian ini, untuk mengetahui konfigurasi pencahayaan alami dan beban pendinginan yang efektif. Dalam kajian ini digunakan metode simulasi dengan objek bangunan hipotetik untuk menguji besar pengaruh dimensi courtyard, (Wall To Window Ratio) WWR dan Jenis kaca terhadap total konsumsi energi untuk AC (air conditioner) dan pencahayaan. Hasil dari kajian ini adalah konfigurasi courtyard yang paling efektif yaitu dimensi courtyard 1, WWR 30%, jenis kaca stopsol. Dari variabel dimensi courtyard, WWR dan jenis kaca, untuk total konsumsi energi untuk AC dan pencahayaan yang paling tinggi berpengaruh dalam efesiensi energinya adalah jenis kaca clear 15.56%, kaca panashap 9.09%, WWR 70% 6,25%, WWR 50% 1,91%, dimensi courtyard 2 0.27%, dimensi courtyard 3 0.18%. Pada kota Jakarta dengan kondisi iklim tropis kurang cocok untuk pengaplikasian courtyard yang terlalu besar, harus di perhatikan proporsi lebar dan tinggi courtyard agar total konsumsi energi untuk AC dan pencahayaan tidak terlalu besar. Sedangkan orientasi bukaan sangat berpengaruh terhadap radiasi matahari, sehingga hindari bukaan dari arah timur dan barat. Untuk range WWR bangunan antara 50 -70% perlu di perhatikan dalam memilih jenis kaca karena semakin kecil SC (Shading Coefficient) maka semakin rendah radiasi matahari. Kata kunci: AC (Air Conditioner), Courtyard, Jenis kaca, Pencahayaan, WWR.

scholarly journals Performance Evaluation of External Light Shelves by Applying a Prism Sheet

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4618 ◽  
Author(s):  
Heangwoo Lee ◽  
Janghoo Seo
Keyword(s):  
Performance Evaluation ◽  
Energy Consumption ◽  
Economic Efficiency ◽  
Energy Savings ◽  
Building Energy ◽  
Full Scale ◽  
Natural Light ◽  
Building Sector ◽  
Sector Research ◽  
Lighting Energy

To address the increased use of lighting energy in the building sector, research on the use of light shelves has been increasing. Previous studies have focused on applying operating techniques to improve daylighting performance, which reduces the economic efficiency of light shelves and the building energy savings. This study proposes the use of prism sheets to improve the performance of light shelves, a concept which was validated by evaluating the performance related to saving building energy and improving indoor light uniformity through a full-scale testbed. This study used an external light shelf with no prism sheet, a window with a prism sheet applied, and a window with both an external light shelf and prism sheet applied as Case 1, Case 2, and Case 3, respectively, and analyzed the illuminance distribution and lighting energy consumption required to maintain the optimal indoor illumination for each case. This study also derived the optimal specifications for each case to save building energy and considered the flow of natural light to analyze the performance evaluation results. The main findings are as follows: (1) the optimal specifications to improve daylighting performance were derived for Case 1, requiring the application of operating techniques; (2) Case 2 was not suitable for saving energy and improving light uniformity when compared to Case 1; and (3) Case 3 was effective in saving building energy. In Case 3, even when the light shelf was fixed at 20° without moving, it saved building energy and improved light uniformity compared to Case 1. However, the prism sheet in Case 3 should be detached during winter to maximize building energy savings.

Naval Energy Management System

2020 ◽  
Vol 26 (3) ◽  
pp. 20-25
Author(s):  
Laurențiu Bogdan Asalomia ◽  
Gheorghe Samoilescu
Keyword(s):  
Energy Consumption ◽  
Power Systems ◽  
New Technologies ◽  
Integrated Navigation ◽  
Integrated Navigation System ◽  
Efficient Management ◽  
Reduce Energy Consumption ◽  
Energy Efficiency Design Index ◽  
Green Ship

AbstractThe paper analyses the role of control and monitoring of electro-energetic equipment in order to reduce operational costs, increase profits and reduce carbon emissions. The role of SCADA and EcoStruxure Power systems is presented and analysed taking into account the energy consumption and its savings. The paper presents practical and modern solutions to reduce energy consumption by up to 53%, mass by up to 47% and increase the life of the equipment by adjusting the electrical parameters. The Integrated Navigation System has allowed an automatic control and an efficient management. For ships, the implementation of an energy efficiency design index and new technologies was required for the GREEN SHIP project.

The Research of Measuring Approach and Energy Efficiency for Hadoop Periodic Jobs

2015 ◽  
Vol 8 (1) ◽  
pp. 206-210 ◽  
Author(s):  
Yu Junyang ◽  
Hu Zhigang ◽  
Han Yuanyuan
Keyword(s):  
Energy Efficiency ◽  
Cloud Computing ◽  
Energy Consumption ◽  
Energy Saving ◽  
Energy Estimate ◽  
Cloud Platform ◽  
Periodic Tasks ◽  
Current Consumption ◽  
Reduce Energy Consumption

Current consumption of cloud computing has attracted more and more attention of scholars. The research on Hadoop as a cloud platform and its energy consumption has also received considerable attention from scholars. This paper presents a method to measure the energy consumption of jobs that run on Hadoop, and this method is used to measure the effectiveness of the implementation of periodic tasks on the platform of Hadoop. Combining with the current mainstream of energy estimate formula to conduct further analysis, this paper has reached a conclusion as how to reduce energy consumption of Hadoop by adjusting the split size or using appropriate size of workers (servers). Finally, experiments show the effectiveness of these methods as being energy-saving strategies and verify the feasibility of the methods for the measurement of periodic tasks at the same time.

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