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.

No description available.

Atualmente, os edifícios selados hermeticamente e com as chamadas \"peles de vidro\" estão presentes em diversos países, e possuem, como consequência, um elevado consumo de energia elétrica para conseguir manter o conforto ambiental dos usuários. Contudo, é possível se beneficiar de uma maior eficiência energética nesses espaços através da combinação de soluções ativas e passivas. Esse estudo tem como objetivo principal avaliar a influência de parâmetros de projetos, tais como o formato da sala, tamanho e orientação das aberturas na fachada, no consumo de energia e no conforto visual em saletas comerciais com ventilação híbrida e integração da iluminação natural com a artificial na cidade de São Paulo. As saletas comerciais analisadas possuem uma área média, diferentes formatos e diferentes aberturas em uma só fachada, representando a solução arquitetônica mais comum encontrada nesse tipo de edifício. Através de análise energética realizada por meio do programa EnergyPlus e da análise lumínica com o programa DIVA-for-Rhino, verificou-se que o formato da sala é essencial para a decisão de um percentual de área de abertura na fachada (PAF) que consuma menos energia. Os resultados mostraram que o uso da ventilação híbrida sempre representou uma economia, atingindo uma redução de até 51% do consumo do ar condicionado para resfriamento e até 26% do consumo de energia total, com os PAF´s de 40, 70 e 100%. Seria interessante considerar elementos de proteção solar que não diminuam a eficácia da ventilação e iluminação naturais nesses ambientes, para se aliar o baixo consumo de energia com menores riscos de ofuscamento. Desta forma, o trabalho auxilia a incorporação destas estrategias para uma maior economia de energia no desenvolvimento do projeto arquitetônico desta tipologia de edifício comercial. / Nowadays, sealed airtight office buildings and so-called \"glass curtain wall\" are present in many countries, and have as a result a high consumption of electric energy to be able to maintain the environmental comfort of the users. However, the combination of passive and active strategies could improve the energy efficiency in these spaces. This study aims to evaluate the design parameters influence, such as rooms shape, the openings size and orientation, in the energy consumption and in the visual comfort in cellular offices with hybrid ventilation system and the integration of daylight and artificial lighting in São Paulo. The analyzed cellular offices have an average area, different shapes and different openings in one facade, representing the more common architectural characteristics found in this type of building in that context. Energy analyses in EnergyPlus and daylight studies using DIVA-for-Rhino were conducted. It was found that the rooms shape is essential for the determination of the window-to-wall-ratio (WWR) for reducing energy consumption. The results showed that the hybrid ventilation use always represented an economy, reaching reduction values up to 51% in the consumption of air conditioning for cooling and up to 26% in cellular offices total consumption, with a WWR of 40, 70 and 100%. It would be interesting to consider sun shading elements that do not reduce the effectiveness of natural ventilation and daylighting in these environments to combine low power consumption with a lower risk of glare. In this way, the work helps the incorporation of these strategies for save energy in the development of the architectural design of this type of commercial building.

Atualmente, os edifícios selados hermeticamente e com as chamadas \"peles de vidro\" estão presentes em diversos países, e possuem, como consequência, um elevado consumo de energia elétrica para conseguir manter o conforto ambiental dos usuários. Contudo, é possível se beneficiar de uma maior eficiência energética nesses espaços através da combinação de soluções ativas e passivas. Esse estudo tem como objetivo principal avaliar a influência de parâmetros de projetos, tais como o formato da sala, tamanho e orientação das aberturas na fachada, no consumo de energia e no conforto visual em saletas comerciais com ventilação híbrida e integração da iluminação natural com a artificial na cidade de São Paulo. As saletas comerciais analisadas possuem uma área média, diferentes formatos e diferentes aberturas em uma só fachada, representando a solução arquitetônica mais comum encontrada nesse tipo de edifício. Através de análise energética realizada por meio do programa EnergyPlus e da análise lumínica com o programa DIVA-for-Rhino, verificou-se que o formato da sala é essencial para a decisão de um percentual de área de abertura na fachada (PAF) que consuma menos energia. Os resultados mostraram que o uso da ventilação híbrida sempre representou uma economia, atingindo uma redução de até 51% do consumo do ar condicionado para resfriamento e até 26% do consumo de energia total, com os PAF´s de 40, 70 e 100%. Seria interessante considerar elementos de proteção solar que não diminuam a eficácia da ventilação e iluminação naturais nesses ambientes, para se aliar o baixo consumo de energia com menores riscos de ofuscamento. Desta forma, o trabalho auxilia a incorporação destas estrategias para uma maior economia de energia no desenvolvimento do projeto arquitetônico desta tipologia de edifício comercial. / Nowadays, sealed airtight office buildings and so-called \"glass curtain wall\" are present in many countries, and have as a result a high consumption of electric energy to be able to maintain the environmental comfort of the users. However, the combination of passive and active strategies could improve the energy efficiency in these spaces. This study aims to evaluate the design parameters influence, such as rooms shape, the openings size and orientation, in the energy consumption and in the visual comfort in cellular offices with hybrid ventilation system and the integration of daylight and artificial lighting in São Paulo. The analyzed cellular offices have an average area, different shapes and different openings in one facade, representing the more common architectural characteristics found in this type of building in that context. Energy analyses in EnergyPlus and daylight studies using DIVA-for-Rhino were conducted. It was found that the rooms shape is essential for the determination of the window-to-wall-ratio (WWR) for reducing energy consumption. The results showed that the hybrid ventilation use always represented an economy, reaching reduction values up to 51% in the consumption of air conditioning for cooling and up to 26% in cellular offices total consumption, with a WWR of 40, 70 and 100%. It would be interesting to consider sun shading elements that do not reduce the effectiveness of natural ventilation and daylighting in these environments to combine low power consumption with a lower risk of glare. In this way, the work helps the incorporation of these strategies for save energy in the development of the architectural design of this type of commercial building.

The industry sector accounts for a vast amount of the world’s total energy use, as much as 37% during 2018. Using energy in a sustainable way is necessary from both an environmental and an economical perspective, and it is therefore relevant to take measurements that result in a more efficient use of energy. One way for industries to become more energy efficient is to recover the waste heat, which is energy that otherwise would go to waste. This report aims to find a method to recover and reuse the low temperature waste heat available at the life science company Cytiva’s production site in Uppsala, Sweden. The proposed solution will be to use the waste heat for heating a vertical greenhouse. The study will examine whether this is feasible, and also how installing photovoltaics affects the energy use. Furthermore, the environmental impact of operating the greenhouse with waste heat is also investigated by calculating the CO2 equivalent. The low temperature waste heat that Cytiva provides relevant for this study is 6683 kW, which will be used to heat up the greenhouse. Simulations in the software IDA ICE will be used to construct and simulate a model of the vertical greenhouse. Results from the simulations show that the chosen size, 25 x 50 x 35.5 meters, gives a good approximation according to the wanted temperature range, 18.3-32.2°C. Furthermore, the results imply that the total energy use, 790 652 kWh, and average power, 90.26 kW is less than the available waste heat and there is a large amount that still is unused. The CO2 equivalent is calculated to be 29 317 kg. A sensitivity analysis is made to evaluate the window-to-wall ratio as well as the size of the entire greenhouse. It showed that both parameters are critical and makes a big difference in the simulations.

Contribution of daylight to employees in terms of health, productivity, and overall wellness in the office spaces are undeniable. Apart from the psychological and biological benefits of employees, embracing daylight in office spaces increases the energy-efficiency of the building which leads to the sustainable development of a city. However, a considerable number of employees in Sweden lack daylight in their workspaces according to a report by the Swedish Work Environment Authority [Arbetsmiljöverket (Swedish)] (Lowden, 2019). Professionals like Architects, Lighting Designers, and students of architecture and lighting design across Sweden were asked their opinions pertaining to lack of daylight in a considerable number of office spaces in Sweden based on their experience through online questionnaires/ interviews to get to know the overview of this subject. Out of all the possible reasons, window design and economy were the two macro factors according to them that influenced daylight in an office building in Sweden but often, obstruction angle in a building due to urban densification is overlooked when it comes to daylight in an office building. This thesis discusses the influence of obstruction angles with an illustrated office building in Stockholm. Diva for Rhino was the software used for the modelling and daylight simulation.