Enhancing of solar still productivity using vacuum technology

In this study the effect of applying vacuum inside the solar still on its productivity is presented. The effect of vacuum inside the still is to avoid any heat transfer due to the convection in the still. So the heat loss from the water in an insulated still is due to the evaporation and radiation only. Hence, the air mass transfer is not included in the analysis. In presence of vacuum the effect of the non-condensable gas which reduces the rate of condensation is also avoided. The results show that applying vacuum inside the solar still increases the water productivity about 100%, i.e. enhancing the efficiency about 100%. This can be considered as the maximum increase in the productivity of the still up to now.