Minimizing building’s energy consumption and carbon footprint in workplaces: Holistic analysis of artificial and natural lighting systems through 3D modeling
Angelos Pantis, "Minimizing building’s energy consumption and carbon footprint in workplaces: Holistic analysis of artificial and natural lighting systems through 3D modeling", Diploma Work, School of Chemical and Environmental Engineering, Technical University of Crete, Chania, Greece, 2023
https://doi.org/10.26233/heallink.tuc.97771
As lighting systems consume a large percentage of the energy balance of buildings – especially in workplaces – their consumption has increasingly gained importance among researchers within the framework of energy conservation. In addition, the goal of climate neutrality by 2050, as well as the current energy crisis, make the design of high–performance spaces more critical than ever.This study investigates the potential for energy savings in the internal lighting system of different workspaces at the Technical University of Crete. To ensure the maximization of energy efficiency, the methodology considers both the upgrade of the existing artificial lighting system and the potential energy gains that can be achieved through the utilization of daylight. The reduction of CO2 emissions (kg/y) is also estimated.Space and lighting environment are modeled using DIALux.evo 12 software (EN12464-1:2021). The simulation examined different types of spaces, such as office space, laboratory, lecture hall, and corridors. Regarding artificial lighting, two individual practices are examined to reduce the installed power. The first one involves the replacement of existing fluorescent lamps with new high-efficacy LED. In the second one, the entire lighting fixtures are replaced, and a new installation location is proposed (according to the current space use), to reduce the installed power while maintaining the required illumination intensity on each surface. Defining activity zones in every workspace, luminous flux is directed in accordance with the specific needs of each area.For every modification implemented in the artificial lighting system, it is ensured that the visual comfort conditions are not disrupted. This objective is accomplished by providing the recommended luminous flux (EN12464-1:2021) and also maintaining the discomfort glare rating (UGR) and uniformity (Uο) within the recommended limits.Determining the occupancy schedule for every space, DIALux calculates the annual energy consumption and cost, annual CO2 emissions, and potential energy savings by utilizing natural lighting for each case.The high percentages of energy savings (62%) come as no surprise, considering the remarkable efficacy difference between the old and new lamps. Daylight harvesting can elevate this percentage to 80%. What is particularly interesting is the further reduction in consumption, achieved by strategically distributing the light intensity based on the usage profile of each space and surface. In that case, the average conservation exceeds 70%, while the utilization of natural light has saving potential up to 90%.