In the present work, experimental study has been done to estimate the performance of solar heating system by air-water (Dual) solar collector. Flat plate dual solar collector with dimensions (120 cm length, 80 cm width and 15 cm thickness) has been used for heating the test space with dimensions (2×2×2.5) m. In this study, the system has been operated in Al-Najaf city with 45o tilt angle to the south. The results obtained that the dual flat plate solar collector daily efficiency is 52.02 %.They also showed the ability to use dual solar collector absorber as heat exchanger in the night to maintain room temperature in the comfort condition for space heating in the winter season.