LAUSR

Abstract Window ventilation is an effective method of hybrid ventilation that helps reduce energy demand for room heat extraction and fresh air supply and improve occupants' satisfaction in the indoor environment. Therefore, it is important to develop solutions that utilize simple interventions and help reduce technical complexity as well as energy consumption. This paper explores the relationship between the window opening grade and energy savings in one-sided window opening in two hot environments, one humid and one arid (Jeddah and Riyadh, respectively). The model simulations considered typical working hours in office spaces that have large cooling loads coinciding with high irradiation. The potential of covering the energy demand using facade-integrated photovoltaics was also explored and related to the increased energy efficiency due to the impact of the window opening grade. Moreover, it is believed that such investigations would help change the attitude toward mechanical air conditioning and provide reference in planning contemporary building that integrated passive solutions. The used energy modelling tool is IDA-ICE 4.7.1. Clear differences in each location's capacity for window opening could be seen. The results indicate a direct contribution to energy savings by opening windows to certain grades for both locations, especially during winter and the intermediate seasons of spring and autumn.