Thermal Performance of Building Envelope in Very Hot Dry Desert Region in Egypt (Toshky)

Toshky region is a desert region located in the south east of Egyptian western desert at the Tropical Cancer (23.5 o N). The following features characterized this region during the summer season; aridity, high summer day time temperatures reaches to above 40 o C for about 6 hours, large diurnal temperature variation, low relative humidity, and high solar radiation reaches to about 1100W/m 2 on horizontal surfaces. In such climate thermal human comfort is crucial to provide the reasonable environment for the people. As the building envelop has a major role in saving comfort for people and improve the consumption of energy in building. So this study is interested in studying the thermal performance for some building constructed from different building materials as; Nobaa sandstone, hollow clay brick, light sand block, and hollow and insulated bazelt blocks. The external climatic conditions and the temperature distribution inside the wall construction and the indoor air temperature were measured. The result shows that using Nobaa sandstone alone in building is not adequate with the external climatic conditions of this region. But using building materials with specific thermal characteristics, and using thermal insulation led to reduce the heat flow through the walls and help the building to be suitable with its external environment conditions. The study also show that hollow clay brick and light sand block valid the lowest indoor air temperature, and the thermal performance of hollow bazelt blocks can be improved by using thermal insulation, Natural and forced night ventilation help the indoor environment to be within the thermal comfort.