Analysis of data from a staged humidification-dehumidification desalination process, using air as a carrier-gas (Dewvaporation process), reveals that the energy reuse factor, f, and molar production flux, P-f (kgmoles/m(2)hr) are quantitatively related to the maximum temperature of saturated evaporation and the number of stages employed, N. The data spanned 3 < f < 25 with 1 < P-f < 4. The f*P-f relationship identifies a hyperbolic form for the case of realistic but large number of stages, N. The relationship can be used to elucidate the effective dry gas heat transfer coefficient from data and, in another form, predict the number of stages needed to satisfy a design after selection of the f, P-f, and the maximum temperature of water saturation. In all cases, the number of stages must exceed the desired energy reuse factor, f, by an order of magnitude in order to reduce the detrimental effect of the number of stages on the f*P-f product to only 10%. For water containing up to 7000 ppm total dissolved solids (TDS), the detrimental effect of the boiling point elevation on the f*P-f product is also only 10%.