Daylight harvesting is an essential strategy that is often used to enhance both the design and performance of an architectural project. Windows, as crucial architectural elements, not only admit natural light into spaces but also provide the occupants with visual connections. However, the excessive usage of windows brings an uncontrolled amount of solar energy to the spaces and negatively affect the building's energy performance. When utilizing passive design strategies such as daylight harvesting, several parameters, including the electrical lighting system, can impact the outcome. The current study investigates the role of lighting systems on daylight harvesting's effectiveness and their impact on window dimension and total energy consumption. In this study, the optimum window-to-wall ratio of an open office in the presence of two different light sources (LED and fluorescent) is explored through a computer simulation method. A combination of tools including AGi32, ElumTools, OpenStudio, EnergyPlus, Radiance, and MATLAB helps to conduct the simulation and deliver optimal results. In the results and conclusion chapter, the study provides guidelines to specify optimal window percentages considering two lighting systems in each cardinal direction. Importantly, the guideline focuses only on energy performance and not on the spatial quality of the design. / Master of Architecture / Harnessing daylight with the use of windows helps to offset parts of the electric lighting needs, and decrease the total building energy consumption. This is accomplished by using glazed materials to admit daylight and lighting control systems, which can respond to the dynamic light level. However, improper implementation of a passive daylighting strategy may cause increased energy consumption. Sunlight is accompanied by solar heat radiation which can increase the HVAC load of a space and compromise the energy savings achieved by daylighting. Therefore, a balance between solar heat and light gain is required to fully take advantage of solar energy without reverse impacts. Concerning the mentioned balance, recent advancements in lighting technology question the effectiveness of natural light in reducing whole-building energy consumption. Due to the high energy efficiency of LED luminaires, lighting power consumption is rather low, even when the lighting system operates at full capacity. Therefore, it is unclear whether the solar energy coming through glazed materials works to the advantage or disadvantage of total building energy consumption. This study hypothesized that the total energy consumption of an open office with LED luminaires would be less in absence of solar energy compared to a scenario which utilizes the solar energy. A simulation-based methodology, using a combination of photometric computation and building energy simulation tools, was utilized to examine the hypothesis and explore the impacts of lighting systems on the optimum window-to-wall ratio. The results provide a helpful guideline which highlights the impact of lighting systems on window dimensions and their mutual effect on whole-building energy consumption. Although the optimum window-to-wall ratios suggested by this study only concern energy consumption, integration of them with occupants' preferences can propose an acceptable window-to-wall ratio that satisfies both design quality and performance of a building.

The analysis of the illumination devices at work have been performed, methods of illumination calculation and their simplified forms have been presented. The set requirements for the lighting systems have been analyzed and the program of the lighting calculation has been investigated. Experiment on measuring the amount of illuminance on the working surface of the room has been executed and the data of experiment has been compared with the calculation results. It has been measured that the data of experiment coincides with the calculation results. Seven separate lighting systems have been examined; their efficiency of lighting the whole working surface and separate working places has been measured. The research on uniformity of illuminance on the whole working surface and separate working places has been performed. The influence of the objects that exist in the room, such as monitors, workers, on the efficiency and uniformity of illuminance in the working places has been examined. Deficiencies and advantages of separate lighting systems have been explained in the performed research. The received results are summarized in the conclusions.

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The main focus of this project is to investigate the energy consumption of the manufacturing lines in the car industry and look for the potential methods regarding energy saving. Special emphasis is put on the lighting technologies that can be used in the manufacturing processes. Two lighting technologies are tested in order to see which one has better performance and lower energy consumption. Fluorescent tube and LED tube are compared concerning illuminance, UV irradiance and power consumption. Economic evaluation is also conducted to exam the feasibilities replacing fluorescent tubes with LED tubes. Results of the study show that the LED tubes have much lower energy consumption than fluorescent tubes, produce more direct and „colder“ light, and have much lower UV irradiance. However, the payback period of LED is relatively long at current price situation. Since it is expected that the price of LED tubes will decrease in future, it is reasonable to predict that the LED technology will change the fluorescent one in many applications. The energy consumption has been estimated for two manufacturing lines which use different technologies to produce car underbodies. In order to identify the differences from the energy consumption point of view, some measurements are conducted, such as the consumption of electricity, compressed air, air for ventilation and cooling water. The measured results show a disproportion in the power consumption when the lines are in stand-by mode. This affects the energy consumption per produced unit significantly. The line that has a higher capacity and a lower power consumption in the stand-by mode has a lower energy consumption per produced unit when it is operating with lower production loading. So, in order to improve the energy efficiency, it is necessary that it works at as high volume as possible and to have the stand-by power consumption as low as possible.

Taiwan lack natural and energy resource, need to import 99.3% energy. Due to the traditional high-carbon energy also supply from abroad, its supply will be impacted by international demand and production, price fluctuations, and the international politics. In recent years the international oil price surged upward, business costs were constantly raise. In this study, some small and medium businesses are taken as objects in Kaohsiung, Taiwan. In this investigation, understand the application of energy resource in those businesses, different industries have their attention to other items and differences, it can be seen on those small and medium enterprises in the concept and practice by measuring and computing power consumption. Research Methods: First, to explore the international and domestic energy and policy and the related energy research literature, interview the small and medium enterprises and observe the way of energy usage, and provide the improving solution, questionnaires and field measurements made on those enterprises, to record the response, investment willingness and problem for energy improving, statistical analysis and get the conclusion. The results showed that the prevalence among the small businesses¡¦ waste of energy, there is many invalid lighting, it is the room to improve the installation of reflective shade to effect the lighting, even replace the lamps (T8) to lamps (T5) with reflective shade, then reduce the use of lamps and power, indirectly to reduce the power consumption of air condition. This research also found there is considerable room to improve the light in the refrigerated cabinet. The traditional fluorescent lamps(T8) be used in the refrigerated cabinet. The performance is low and produce high temperature, then the refrigerated cabinet shall expand more power to reach the set temperature, if change those lamps to LED lamps could immediately reduce the loss of electricity bills. Extension of this study, there is a great improvement in the domestic building and enterprises on lighting application, it could reduce a lot of power consumption by detailed observing, detected, and improving engineer to remove lighting waste, and thus achieve carbon reduction targets by 20% of the electricity.

Light guide is a tubular skylight with mirrored internal surface. It is a lighting device bringing daylight into the interior of a building without windows or into rooms with insufficient daylight. It presents the potential for energy savings, opens the possibility to use places that are not well lit and offers opportunities for improving the visual comfort of the indoor environment. This thesis reviews the potential of light guide system as a daylighting approach in building and presents results of experiments on performance of tubular skylight prototype. The main task of the thesis is focused on comparison of traditional light guide system and newly developed prototype, examination of its light transmittance and efficiency as well as its thermal behaviour in order to find possible improvements for applications in buildings.

The lighting retrofit method is adopted as one of the solutions to reduce lighting energy consumption and improve lighting quality in existing buildings. Lighting controls and energy-efficient light sources are used to achieve the goals of the lighting retrofit. Nowadays, Light-Emitting Diodes (LEDs) are replacing traditional lighting technology owing to their high efficiency and longevity. One of the advantages of LEDs is the controllability function, which allows users to set the light level according to their preferences. This saves more energy and satisfies users’ lighting needs. However, over time, the performance of lighting retrofit projects deteriorates subject to failure of the retrofitted lights. Therefore, to maintain the performance of lighting retrofit projects, maintenance must be planned and performed. The impacts of the users’ lighting level requirements on LEDs’ life characteristics and lighting system performance are investigated by using lighting controls. Light and occupancy sensors adjust artificial light to the light level required by users and detect the presence of users in the zones, respectively. Light sensors measure the average illuminance in the zones. The measured illuminance is compared to the users’ set illuminance; if the measured illuminance is higher than the users’ set illuminance, lamps are dimmed to meet users’ lighting preference, when the measured illuminance is less than the users’ set illuminance, lamps in the zone are replaced by new ones. The dimming level in each zone at each sampling interval is used to estimate the operating junction temperature, thereafter the degradation rate and luminous flux are calculated. Light levels at workspace are modelled using the lumen method. This model helps to quantify energy savings and predict when lamps will fail to deliver the required light levels. In existing studies, users’ lighting level requirements are neglected when investigating the lifetime of the lighting system; however, users’ profile and driving schemes affect the operating conditions of a lighting system. From the simulation results, it is noted that lumen output degradation increases when the user’s set illuminance is above the illuminance required under normal operating conditions and decreases when the user’s set illuminance is below the illuminance required under normal operating conditions. Increased lumen output degradation shortens the lifetime of LEDs and reduces energy savings, while decreased lumen output degradation extends the lifetime and increases energy savings. Generally, lighting retrofit projects contain a large lighting population; investigating when each lamp will fail can be time-consuming and costly. In this research, a mathematical model is formulated to model LEDs’ failure by analysing the statistical properties of the lumen degradation rates. Based on the statistical properties of the degradation rates, the cumulative probability of failure distribution and the survival function are modelled. The formulated survival function is incorporated into the lighting maintenance optimization problem to balance energy savings and maintenance costs. A case study carried out shows that, in 10 years, the optimal lighting maintenance plan would save up to 59% of lighting energy consumption with acceptable maintenance costs. It is found that the proposed maintenance plan is more cost-effective than full maintenance. It is concluded that lumen degradation failure should be considered when investigating the performance of lighting retrofit projects, as this may not only affect energy savings but also reduce the level of illumination, which can cause visual discomfort. The initial investment costs of LEDs are still a barrier to the implementation of LED lighting systems in residential buildings. Energy-efficiency projects often face hurdles to access capital investments because decision-makers and funders do not have enough information about operational savings the project can provide and specific financial requirements applied to efficiency investment. In this research, an optimization model is formulated to give decision-makers and funders detailed information about the performance and operational savings that a LED lighting retrofit project can offer and its economic viability. The lumen degradation failure model developed is used to monitor and estimate the energy savings, and the optimal maintenance plan is scheduled to replace failed lamps. In the existing studies, the economic analysis of the lighting retrofit projects is assessed based on lighting population decay due to burnout failure while in this research economic analysis is assessed by considering the lumen degradation failure. The case study results show that the substitution of halogen light bulbs with LED light bulbs could save up to 291.4 GWh of energy consumption, and reduce 273:92 103 tons of CO2 emissions over 10-year period. The optimization model formulated is effective to help the decision-makers and funders to quantify the savings and assess the economic viability of the LED lighting retroïnˇA˛t project. This optimization model can help the decision-makers and funders to make an informed decision. / Thesis (PhD (Electrical Engineering))--University of Pretoria, 2020. / Electrical, Electronic and Computer Engineering / PhD (Electrical Engineering) / Unrestricted

Sistemas de operação remota e supervisão de iluminação pública são compostos por dispositivos acoplados aos pontos de luz interligados via rede, e aplicativos que são executados em computadores que indicam problemas nos pontos de iluminação e apuram o valor do consumo de energia. Estudar as tecnologias dos trabalhos correlatos, propor um sistema dedicado para iluminação pública e implantar o sistema proposto em um teste piloto para avaliação das características de operação e supervisão são os objetivos do trabalho. A arquitetura do sistema proposto é modular e expansível. O modelo baseado em células permite que novos conjuntos de dispositivos possam ser adicionados de acordo com a demanda. No desenvolvimento do trabalho a linguagem C# é adotada para desenvolver a operação e supervisão através do padrão CyberOPC (Cybernetic OPC) e arquivos do tipo XML são aplicados para descrição dos dispositivos e definição da topologia da rede. Os resultados obtidos em simulação e no teste piloto validam a metodologia e arquitetura proposta. / Systems of remote operation and supervision of public lighting are composed of devices attached to the light points interconnected via a network, and applications that run on computers that indicate problems with lighting points and discharge the amount of energy consumption. Studying the related works technologies, propose a system dedicated to public lighting and deploy the proposed system in a pilot test to evaluate the operating characteristics and supervision are the objectives of the work. The architecture of the proposed system is modular and expandable. The cell-based model allows new sets of devices can be added according to demand. In developing the work the C # language is adopted to develop the operation and monitoring via standard CyberOPC (Cybernetic OPC) and XML file types are applied to the device description and definition of the network topology. The results obtained from simulation and from the test pilot validate the methodology and the proposed architecture.

Sistemas de operação remota e supervisão de iluminação pública são compostos por dispositivos acoplados aos pontos de luz interligados via rede, e aplicativos que são executados em computadores que indicam problemas nos pontos de iluminação e apuram o valor do consumo de energia. Estudar as tecnologias dos trabalhos correlatos, propor um sistema dedicado para iluminação pública e implantar o sistema proposto em um teste piloto para avaliação das características de operação e supervisão são os objetivos do trabalho. A arquitetura do sistema proposto é modular e expansível. O modelo baseado em células permite que novos conjuntos de dispositivos possam ser adicionados de acordo com a demanda. No desenvolvimento do trabalho a linguagem C# é adotada para desenvolver a operação e supervisão através do padrão CyberOPC (Cybernetic OPC) e arquivos do tipo XML são aplicados para descrição dos dispositivos e definição da topologia da rede. Os resultados obtidos em simulação e no teste piloto validam a metodologia e arquitetura proposta. / Systems of remote operation and supervision of public lighting are composed of devices attached to the light points interconnected via a network, and applications that run on computers that indicate problems with lighting points and discharge the amount of energy consumption. Studying the related works technologies, propose a system dedicated to public lighting and deploy the proposed system in a pilot test to evaluate the operating characteristics and supervision are the objectives of the work. The architecture of the proposed system is modular and expandable. The cell-based model allows new sets of devices can be added according to demand. In developing the work the C # language is adopted to develop the operation and monitoring via standard CyberOPC (Cybernetic OPC) and XML file types are applied to the device description and definition of the network topology. The results obtained from simulation and from the test pilot validate the methodology and the proposed architecture.