ABSTRACT Enhancement forced convection solar still of a closed cycle type is designed and manufactured for which experimental work is conduced. The performance of such still based upon the hourly variation is presented to cover different parameters, such as fluid temperatures along the channel, productivity and efficiency. The effect of air mass flow ranging from (0.0303 to 0.05424) kg/sec and condenser cooling water temperature ranging from (27 to 33 ) C for the basic still is investigated. The optimum air mass flow for the basic still is found to be equal to 0.052 kg/sec, and the reduction in cooling water temperature from 33 C to 27 C produce and improvement of 17 % in the productivity. The basic still is modified by introducing a humidifier to enhance its yield. The improvement in yield and efficiency is in the order of 12 % and 7.75 % respectively.