Desiccant cooling has been considered as an alternate option in contrast to vapor compression systems and has been broadly researched in last few years. Use of metallic gas liquid contacting surface is very common due to good wettability of metallic surface. But, corrosion problem is the main limitation of metallic surface and it requires the replacement of surface; thus, adding up extra cost plastics can be used as an alternative of metal contacting surface, but plastic has not so good wettability as metal surface. So in order to enhance the wettability of plastic plate, an experiment is carried out. In this experimental study, wettability factor of polypropylene plate has been measured on vertical falling film tower. For enhancement of the plate, total four surface modifications were selected according to the channel width 2, 3, 4, and 5 mm. In this investigation, fluid (water) is used at different mass flow rate. It is found that average wettability factor of plate 1, plate 2, plate 3, and plate 4 are 0.51, 0.54, 0.52, and 0.49, respectively.