The modeling equations for predicting distillate flux in a double-unit air gap membrane distillation (AGMD) module with inserting corrugated carbon-fiber open slots of various hydrodynamic angles were developed theoretically and experimentally. The double-unit design gives a more compact module with an increase in pure water productivity for desalination applications. The operation of AGMD module with inserting carbon fiber spacers results in a higher permeate flux as compared to that of the module with an empty channel. The corrugated carbon-fiber open slots acting as an eddy promoter could not only strengthen the membrane stability for preventing from vibration but also enhance the distillate flux with lessening temperature polarization effect. The correlated expression of Nusselt number for inserting corrugated carbon-fiber open slots was formulated incorporating with experimental data, and thus, the prediction of the heat transfer coefficient for the AGMD module was obtained. The temperature distributions were represented graphically with the volumetric flow rate and inlet saline temperature as parameters. The effects of volumetric flow rate, slot thickness and fluid inlet temperature on the permeate flux were also delineated with considering the power consumption increment due to inserting corrugated carbon-fiber open slots. The good agreement between the experimental results and theoretical predictions was accomplished.