Experimental study of liquid-desiccant–evaporative cooling for data Center heat recovery

Abstract

This study presents an experimental evaluation of a rack-level cooling system that integrates rear door heat exchangers with liquid desiccant dehumidification and evaporative cooling to improve thermal efficiency and waste heat utilization in data centers. A test platform simulating a 20 kW server rack was constructed to compare a conventional system with the proposed configuration under humid outdoor conditions. The proposed system recovers approximately 98% of condenser heat, of which about 63% is functionally reused for desiccant regeneration, achieving a total heat recovery utilization rate of 62%. Compared to the baseline, the proposed system reduced cooling-related electricity consumption by up to 29%, primarily due to reduced refrigeration power demand. Results also show lower condensing pressure and compression ratio, leading to improved coefficient of performance and power usage effectiveness. The findings highlight the potential of liquid desiccant-assisted cooling for enhancing energy efficiency and heat reuse in hot and humid climates.