Solar Hybrid Cooling System Using Variable Speed Compressor

The present work investigates experimentally the effect of varying the rotating speed of a compressor on the power consumption of an air conditioning system assisted by a solar collector. The outdoor temperature in Iraq exceeds 50 ℃ in summer months. This weather effects on the power plants and also needs an air conditioner, which is the principal on high electrical demand. So, the need of power saving is available. This work aims to save power and increases the COP of the A/C units by using a variable speed compressor. The experiments were carried out by using a hybrid system that includes an evaporator indoor, condenser and compressor outdoor plus the vacuumed pipes solar collector to air condition a room of 3×4.5×3 m under 46 ℃ ambient temperature and with three speeds (1400 rpm, 934 rpm, and 467 rpm). The system uses R22 as a refrigerant. The flow of the refrigerant is controlled by using solenoid valves to select the path after compressor either to the condenser or to the solar collector considering its temperature. The results manifested that the best COP obtained is with the lowest speed.