Three experimental distillers were designed, constructed and installed at the Agricultural Engineering Research Institute (AEnRI) in order to desalinate water during May 2003. These units were constructed as box shape with three different tilt angles (20^°, 30^° and 40^°), single and double glass covers. Black basalt stones were used inside the distiller during the distillation experiment to store energy which was absorbed from the sun during the day light and used through the night. Comparative studies were made between the effect of shape factor with different tilt angles and different covers (single & double) in order to assess the desalinating water by using the net energy radiation among distillers' surfaces. The data obtained showed that the salinity of water reduced from 1990 ppm before testing to the range zero to 30 ppm after desalinating. The average discharge of each unit was 3.1, 3.3 and 2.2 1/m² and increased to 4.06, 4.2 and 2.4 1/m² for tilt angles 20^°, 30^° and 40°, respectively, when double glass cover and basalt stone were used.