No abstract

No abstract

Most urban and, recently, rural households in Egypt live in apartment buildings. Their faç ades 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.

No abstract

Passive buildings conserve energy by decreasing need for HVAC, but it is hard to achieve full thermal comfort unlike air-conditioned buildings. mixed-mode buildings depend on passive mode when thermal comfort is achievable with natural ventilation and switch to active mode otherwise, it can give the building the best of both worlds. Mixed Mode building is a combine of natural ventilated building and AC building which needs different strategy of design which make the Mixed Mode building face a problem in design. this paper aims to reach a strategy to design mixed mode buildings envelope in greater Cairo to reach optimum energy consumption. the research concludes that the MMB is near to be a natural ventilated building with slight heavier south envelope which reach 0.8w/m2.k and 20% WWR although the north façade still a light skin with 2w/m2k and 50% WWR.