School buildings have an enormous impact on the student’s health, well-being and educational achievement; they have also impact on the energy consumption and other natural resources. Most school buildings in Palestine are not equipped with heating and cooling systems because of the lack for fund and the high energy prices. Passive design solution to improve building performance in terms of thermal comfort and energy efficiency is one of the best solutions for school buildings in Palestine climatic and economic contests. This paper aims to evaluate the effects of passive design solution for a selected pilot school on indoor thermal comfort and future potential energy saving.
The case study project is a three story building with a total floor area of 2,780 m2, located in the city of Hebron in the south of West Bank. The climate in Hebron is characterized by relatively cold winters and hot summers, with periods beyond the official holiday when schools in winter as well as in summer are closed due to thermal discomfort. Particularly in winter, temperatures in the area are not in line with current comfort standards, with major effect on the continuity of operating the school and the student’s ability to learn and concentrate. To overcome this situation the project uses passive design strategies including solar chimney, solar wall, underground duct, shading and building orientation as passive design solutions to improve thermal comfort.
During the building operation phase, a quantitative analysis was carried out based on ﬁeld measurements by recording thermal comfort parameters (mainly air temperature, relative humidity and daylight level) for one year in selected classrooms (where different passive techniques have been used) and compare the results to a control classrooms (with no solar wall and no connection to underground duct and solar chimney) in the same school. The results were compared also to outdoor air temperature and relative humidity.
The study has provided positive results conﬁrming that the passive environment control system employed in the selected pilot school is highly effective in providing thermal comfort indoors in hot and sunny days. The chimneys linked to the underground duct act as good ventilators for these days and they could stabilize room temperatures in the classrooms at comfortable temperatures and humidity rates. The impact of ground ducts, and solar chimneys in cold days was relatively small, as winter heating using earth ducts was not a major goal for the designer. However, direct solar gain from eastern and southern windows and solar wall have together led to slightly improve thermal comfort in the tested class rooms during heating season. Most tested classrooms in the three floors of the building, were found to be uncomfortable in winter. This can be attributed to huge thermal mass of the building and ventilation control for solar chimney which is linked with underground duct. The limited amount of heat gain in ground ducts and solar wall were not enough to heat the building without auxiliary mechanical system.