A direct contact membrane distillation (DCMD) equipped with a solar absorber was designed for saline water desalination and integrated into a small unit, that possesses a combined solar absorber for an energy source and membrane distillation process for desalination. The proposed device performs at middle temperature (about 35–50 °C) using hot saline water at the inlet associated with a constant cold stream inlet. The solar absorber is inserted between the glass cover and membrane to heat the flowing fluid which passes underneath the absorber plate. A two-dimensional mathematical energy model and a general numerical method are presented to obtain the water productivity, absorber plate and flow conduit temperature distributions. The results show that the theoretical predictions agree fairly well with the experimental results using a combination of Knudsen diffusion and viscous flow models for membrane coefficient estimation. The maximum trans-membrane flux increment in this study is obtained as 16.56% and the distillation ability potential is 4.1 kg/(m2 h) with high purity.