Experimental Study of Hygrothermal Exchanges in an Evaporative Heat Exchanger Based on Fired Clay Plates for Air Cooling in Hot and Dry Climates

Abstract

In hot and dry climates like Burkina Faso, conventional air conditioning is energy-intensive and costly, accounting for 20% of global energy consumption according to the International Energy Agency. The "Argiclim" evaporative heat exchanger, developed at the Renewable Thermal Energy Laboratory (L.E.T.RE) of Joseph KI-ZERBO University, uses porous fired clay plates to cool air through evaporation. Tested from April to June 2023, the prototype (18x18x2 cm, PVC casing) achieved a saturation efficiency of 92%. It reduced the temperature from 42°C to 29°C and increased relative humidity from 30% to 95% under conditions with an inlet air temperature of 42°C and 30% relative humidity, with a 2 cm plate spacing. Measurements using type K thermocouples (accuracy ±1°C) and hygrometers showed a 15°C temperature drop and a relative humidity of 95% at 2 cm from the duct. Simulations using Matlab, based on Luikov’s equations, validated the experimental results (deviations <5%). Despite high outlet humidity and water dependency, "Argiclim" offers a sustainable and cost-effective alternative to traditional air conditioners, leveraging local materials for accessible thermal comfort in Sahelian regions.