Experimental study on performance improvement and energy savings of split-type air conditioning system using direct evaporative cooling in hot Iraqi climate

The challenge of electricity consumption is one of the most pressing Global issues today. Air-conditioning systems represent a major part of this consumption, and their impact is even more visible in hot-desert climate. A practical approach to mitigate this problem is to pre-cooled ambient air before it enters the outdoor unit, which not only improves system performance. In this experimental study, a split-type air conditioner of 1.5-ton capacity was tested under the summer conditions of Karbala city, Iraq. Direct evaporative cooling technique was adopted using a 100 mm thick cellulose pad, positioned 55 cm away from the outdoor condenser to allow better air-moisture mixing. Comparative measurements were carried out between the conventional units and the modified one. The results showed a reduction in power consumption by up to 24.56% and an increase in coefficient of performance by nearly 37.47%. From an economic point of view, the analysis revealed that the maximum saving in annual electricity cost was about USD 20.45, while the life-cycle saving ranged between USD 220 and USD 365. The payback-time of the initial investment was estimated around 3 years which indicates a relatively short recovery time. Such findings provide a meaningful signal toward adapting environmentally friendly strategies.