Energy-efficient envelope design for schools in Saudi Arabia

Abstract

School buildings are characterized as being envelope-load dominated buildings. Hence, they are greatly influenced by the outside climatic conditions. Due to the harsh climate of Saudi Arabia, government buildings including school buildings on average consume more than 11% of the total energy used. The bulk of this energy is consumed by the air-conditioning systems, which remove a substantial amount of gained heat due to poor thermal envelope performance. Therefore, proper design and selection of components of the building envelope at early stages of the design process can greatly help in achieving thermal comfort with minimum reliance on air-conditioning systems, and also minimizing energy requirements. This research aimed to evaluate the thermal performance and the impact of the critical parameters of building envelope on the annual required cooling and total energy of school buildings. In order to achieve this, a typical school building was developed as a base case. Envelope design practices were defined and twelve design parameters were selected for the base case to represent the wide variation of thermal characteristics. The energy performance of a typical school building in Dhahran is evaluated under various envelope designs using different envelope design components that cover a wide range of thermal characteristics. This evaluation was performed using the energy simulation program Visual-DOE. Parametric analysis was conducted for wall and roof designs, glazing types, window to wall ratio (WWR), orientation, various air infiltrations and combination of envelope design parameters. Initially, for each envelope design parameter a few relevant types of designs were selected that are currently used for buildings in this region. Then, among the selected types of designs the most appropriate type of design was selected for each envelope design parameter. Finally, these selected types of designs were combined to produce an effective envelope design. The cooling and