Do non-metallic material and radiation shields affect the operation of direct evaporative cooling systems?

•The performance of a DEC system manufactured by RFX-PSS has been studied.•The effect of using radiation shields on DEC systems has been investigated.•Using the RFX-PSS-casing instead of metal-casing increases saturation efficiency.•Inclined roof increases the saturation efficiency of DEC systems significantly.•Glass wool-aluminum radiation shield decreases water consumption of DEC systems.