Simulated comparative investigation of the daylight and airflow of the conventional Egyptian shutter ‘ sheesh’ and a proposed latticework device ‘new mashrabiyya’

Abstract

Most urban and, recently, rural households in Egypt live in apartment buildings. Their façades typically consist of openings equipped with glass panels and wooden louvred shutters, known as sheesh. Although it blocks direct sunlight and ensures privacy, sheesh impedes entry of needed air and daylight and obstructs the view. In previous studies, a preliminary proposal concerning the replacement of the conventional sheesh has been presented. This paper reports the investigation that compared the daylight and airflow performances of the sheesh and the proposed latticework device (new mashrabiyya). A simulated comparative investigation of daylight and airflow in a southward facing room (when equipped with sheesh vs. when equipped with the new mashrabiyya) was carried out using Ecotect, Radiance, Evalglare and WinAir simulating programs. The findings show that when occupants shut the sheesh for shading or privacy purposes, no air was admitted at all and would give a very dim interior as a result. By contrast, opening sheesh for ventilation purposes would likely produce visual discomfort. On the other hand, the use of the mashrabiyya was shown to provide a favourable airflow pattern. Illuminance in most of the room was better than the case of when sheesh was used; and when adjusted, would provide comfort for the occupants.