The increasing need for a freshwater supply has led researchers to suggest improved solar stills as one solution to the problem of water shortages. For this purpose, to cover the maintenance and performance gap in this field, three enhancement techniques, including rigid PVC boxes, sliding absorber plates, and air stones at different water depths, are tested in the solar stills. The highest daily production and efficiency for rigid PVC insulation boxes (case A) were about 23 % and 7.6 % more than the conventional solar still and more proper than many previous studies. The maximum daily production and efficiency of an improved solar still with air stones (case B) with water depths of 2 have been 4192 mL/m2 and 42 %, respectively. The daily production of case B with a water depth of 2 cm and air stone lengths of 0.1 m, 0.3 m, and 0.55 m was 22.6 %, 27.6 %, and 34.7 % higher than the conventional one. By comparing the cost per litre (CPL) of the conventional and improved solar stills, it was observed that the CPL in cases A and B was 0.013 $/L and 0.016 $/L, which was about 16 % lower and 11 % higher than a conventional still, respectively.

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