Abstract
The present study is an experimental investigation to improve the performance of the air conditioning unit (ACU) by precooling the condenser with a cooling water loop using a water heat exchanger with the employment of energy and exergy analyses under various ambient temperatures between 30 – 45°C at different inlet water temperatures; 15, 19, 24 and 30°C and water flowrates; 9, 11, 14 and 15.8 L/min. The results indicated that the cooling water loop have a large effect on the exergy destructions as compared with those of the no water case. When a cooling water loop is used, the compressor, evaporator, and expansion valve irreversibilities reduced. The exergy efficiency of the unit decreases as Tamb increases to about 23%; while, the exergy efficiency increases when cooling water loop is used depending on the inlet water temperature and water flowrates. The maximum enhancement in the exergy efficiency is obtained at high water flowrate for Twi = 15°C with a percentage value about 13% as compared with those of the conventional ACU.
