It's difficult to say because with air flow greenhouse heating effect may reduce. If the temperature difference between the glass and water surface reduce the evaporation rate may decrease. It is true moisture evaporation is if the system is opened. So, for a closed system its difficult to say about the combined effect. Last it is desalination system, so with air condensate water collection may become complicated.
@ Mr. Smith Tiwari, Thanks a lot for your answer. But we have a closed system, where air supplied can help to transport vapor from water suface to glass cover that can help to condensation however it can cooling the surface water. There are two competition effect. I think there is an optimum air mass flow rate where productivity is maximum.