SOLAR EARTH-WATER DISTILLATION FOR WET SAND.

Solar earth-water distillation is a means of extracting moisture from an earth medium. Three designs of the hot-box type of solar earth-water still were tested using wet or saturated sand. The designs included: low height with reflective interior siding, tall height with reflective siding and tall height with absorptive siding. A twenty-centimeter-tall still with reflective siding produced significantly greater yields than one twice as tall. No significant difference in the yield between tall stills with light-absorptive versus light-reflective interior siding was found. A regression equation was developed to predict water production for a low still with reflective siding and a sixteen-degree cover slope. Independent variables included soil moisture, solar radiation and maximum and minimum daily temperature.