An experimental investigation on the novel hybrid indirect direct evaporative cooling system

The Evaporative Cooling Technology has revived in the past few decades owing to the gradual shift of economies towards investing in sustainable cooling systems which has led to many governments defining sustainability targets in reducing GHG emissions and achieving climate neutrality with many EU countries aiming to reach net zero emissions by 2050. The major contribution towards GHGs are the conventional air conditioning systems which incorporate energy intensive compressor units and refrigerants as working fluids. A great deal of research has been done on the Evaporative Cooling Technology particularly, the DEC – Direct Evaporative Cooling systems due to their cost-effectiveness, design simplicity and feasibility. The present study proposes a HIDEC – Hybrid Indirect Direct Evaporative Cooling System as an alternative to the conventional vapor compression systems which is unique considering its compact and two in one design incorporating both Indirect and Direct Cooling Channels in a single system. The HIDEC Experimental System is developed passing through the stages of fabrication and design, followed by realtime testing in the hot and humid, and hot and dry sub tropical climatic conditions of Islamabad. The HIDEC Experimental System when operated in Dual Hybrid Mode provides a substantial supply air temperature drop to 24.8 °C with a maximum achievable COP of 35.2 and Cooling Capacity of 16.8 kW. The overall wet bulb effectiveness of the system elevates to 85%, whereas the dew point effectiveness reaches a maximum of 80%.