Evaporation of saline water in solar stills is a common method in producing freshwater. Commercially passive solar stills produce around 3–4 kg/m2/d and are therefore mostly used for smallscale water production [11]. If solar stills were used to humidify the air, they would be more efficient than ordinary stills since the induced airflow would increase the evaporation rate from the water surface. Although solar stills are suitable for humidifying air to the system, using any other heat source for the evaporation would be possible