Energy rationalization for an educational building in Egypt: Towards a zero energy building

Abstract

Buildings have been consuming energy and resources at an ever-increasing rate worldwide. Given the rising living standard, population growth and global warming, energy saving techniques have been recently adopted in the framework of high performance buildings, also known as near zero-energy buildings. This is particularly true for Egypt since over the past decade, the energy consumption has witnessed an unprecedented increase particularly for the buildings sector whose share in the electricity consumption can reach 66%–74%. Hence, it is timely for Egypt to upgrade its building construction code by mandating energy rationalization. This work investigates the effects of applying energy rationalization for a non-residential building in Egypt. As a case study, the Mechanical Engineering Department building at the Faculty of Engineering Campus of Ain Shams University, was modelled using EnergyPlus as a typical educational building. A number of retrofitting strategies and energy saving techniques have been assessed and compared to reach an optimized building envelope with minimum energy needs (energy rationalization). Retrofitting the building walls resulted in a significant contribution to the energy saving (>20%). Combining various building envelope retrofitting strategies dropped the building energy consumption by more than (>36%). Furthermore, using energy efficient measures by upgrading the mechanical HVAC systems used to condition the retrofitted building led to energy savings of more than 50% and a drop in the system capacity by more than 65%. Subsequently, a solar PV system is sized to cover these rationalized energy needs with a payback period of 4–5 years, thus transforming the sample building with annual energy use intensity (EUI) of ∼ 230 kWh/m2 into a near zero-energy building with an EUI of ∼106 kWh/m2.