A solar humidifier unit used for humidification of an air conditioning system is presented. A Runge–Kutta procedure of fifth order has been used to solve the governing equations. Solar energy data as well as ambient temperature data for one hot summer day were used in calculation the inside temperature of the humidifier as well as other parameters to determine the effective use of the solar humidifier. The results obtained are promising to corporate it with an A/C system. The amount of vapor produced reaches a maximum value at the time when the ambient temperature reaches also a maximum value and the relative humidity reaches a minimum values.