All of these calculations assume that the air, once the water is absorbed out of it, will flow out of the vessel and be replaced by humid air again at the optimal speed. It also requires power to operate. It may be that the power is used to pump the air which would mean the system has only one of these drawbacks, but the article is light on details so I can't be sure. It is also not a system that can be built at home. On the other hand I read an article by an engineer a few years ago that proposed a system that used piping running below the ground to cool the air and cause condensation, using a wind catcher at one end to push it through. His estimates included air flow and showed that a 10 meter long system could provide drinking water in desert air with a moderate wind for several people. I am unable to find the article again unfortunately.

My point is that a temperature gradient is far cheaper and available to poor third world desert countries where such a system is required. This technology is neat but not all that practical. Still a combination of the two systems, ie. lining the inside of underground pipes with this substance and letting the wind push air through might have a much higher rate of condensation and could be used for commercial and military operations in the desert.