A Study on Building Energy Modelling and Energy Efficiency Strategies for Educational Buildings

Abstract: The building sector is one of the sectors with the highest energy utilization and is one of the largest sources of CO2 emissions worldwide. At the same time, energy prices in Europe have significantly increased in recent years. For these two reasons, energy efficiency in buildings has become highly relevant for public and private organizations aiming to reduce energy consumption for the operation of buildings and therebyd ecrease their carbon footprint and operation costs for users and owners. This master’s thesis aims to identify areas of opportunity for energy utilization reduction and the implementation of energy efficiency strategies in four buildings of the KTH Campus, owned by Akademiska Hus. First, an energy data analysis of the last years of the operation of the buildings was conducted to identify trends and atypical energy uses. Next, energy audits were performed on the most important energy-consuming equipment and major building facilities to understand the operation conditions and characteristics of electrical, heating, and cooling systems, aiming to identify areas of opportunity for reducing energy use from current operation of the buildings. Subsequently, after understanding the energy use in the four buildings, models of the buildings were created in IDA ICE. The approach involved two steps: first, modeling the buildings’ geometry and adapting their energy consumption to match the patterns identified in the previous data analysis; and secondly, modeling the implementation of energy efficiency strategies on the buildings that aim to improve the findings of the data analysis and energy audits performed previously. These energy efficient models were subjected to energy performance analysis, economic analysis, investment feasibility analysis, among others. The results obtained from the models with energy efficiency strategies showed energy and economic savings that varied from building to building through the automation of lighting systems in the buildings, with an average return on investment of 2.5 years. Likewise, significant savings were achieved by reducing the heating setpoint during nights, causing the district heating usage to differ from the daytime demand, resulting in savings between 5 % and 8 % of the total annual energy use in the buildings, without any required investment. Additionally, the implementation of renewable energy solutions was studied by modeling the use of solar panels in the buildings, leading to a reduction in electrical grid demand between 20 % and 48 %, depending on the available area for the panels, with an average return on investment of 5.5 years. Other strategies were also studied and discussed in this report. In conclusion, this study provides evidence of the energy, economic, and environmental feasibility of different energy efficiency strategies that can be implemented in the buildings of the KTH campus. These strategies contribute to achieving the environmental objectives of Akademiska Hus and KTH.