Comparison of plastic and glass condensing covers for solar distillers

Abstract This paper compares the productions of several solar stills of different designs, some with double-strength window-glass covers and others with plastic-film covers. Two small identical solar stills were designed and tested over a period of two years. One was covered with a double-strength window glass (0·125 in. thick) and the other was covered with a Tedlar plastic film (0·002 in. thick) which was mechanically treated to produce a wettable surface. Of the four other solar stills tested, three were covered with the Tedlar film and the fourth was covered with the double-strength window glass. These units were of differet designs. Three of them were of the same size (48 sq. ft) whereas the fourth was considerably larger (240 sq. ft). The data indicated that production of the stills covered with the Tedlar film was consistently less than that covered with glass for both small and large stills. The operating and design problems connected with both covers are reviewed.