Solar energy is becoming increasingly important due to energy shortage and pollution crises. This research is an attempt to make use of solar energy for domestic heating, crops drying and other purposes. Iraq is known for its sunny weather where the annual sunny hours are about 3300. In this research the design, construction and performance testing of a solar air heater is presented. The air duct, a cross-section area of (10x10) cm, is fabricated in the absorbing plate. A sufficient length of the duct was found to be 4.5 m. Thermocouples type (k) were used to measure temperatures of the absorbing plate and air as it flows through the duct by using interface device. Different types of black paints were prepared for painting the absorbing plate. Different tests were performed to choose the most suitable paint by painting sample pieces of the absorbing plate material and exposing these samples to solar radiation and measuring the maximum temperature rise of each sample during a specified period of time. The paint type which gave the maximum temperature rise was chosen to paint the absorber plate. After construction and assembly the rig was tested for different orientations with a tilt angle of 45°. The results obtained showed that the maximum temperature rise occurred at 14:00 PM o'clock for the south-east direction with a minimum mass flow rate (0.109 kg/s) since the maximum solar radiation occurred at this time. The clean glass cover condition gave a maximum temperature rise equals to 50.69 °C which is higher than the results of the dirty glass for the same test condition. The results of this study show that the best orientation for Iraq climate is the south- east direction.