The variations of hourly fresh water productivity per unit area for the modified and conventional
solar stills are presented in Fig. 7. It is found from Table 1 that the amount of accumulated distillate
water for the modified solar still is greater than that of conventional still. Addition of nanofluids in the
basin surface increases the water temperature by increasing heat transfer rate and thereby increasing
the evaporation rate. It can be observed from Table 1 that, at constant fan operating speed of 1350
rpm during the day, it was found that the productivity is increased when using the nanoparticles of
aluminum oxide approximately by 116 % as compared to the conventional still. And when using the
nanofluids without operating the fan, the productivity of the modified still is increased approximately
by 76 % as compared to the conventional still.