Experimental study of the influence of pad angle on the thermal performance of a direct evaporative cooling system

Abstract One of the most important parts of direct evaporative cooling systems is the cooling pad. Pads vary in materials and construction features. The parameters studied in the performance of the pads are air speed, pad thickness, geometrical characteristics, and its configuration and the provided water flow rate. The performance of the pads is usually determined through saturation efficiency, pressure drop, temperature drop and humidity increase in the treated air, evaporation and water consumption, cooling capacity, coefficient of performance, and heat and mass transfer coefficients. Since the geometry and how to place the pad in the evaporative cooling system is one of the most important issues related to the performance of such systems, the present work experimentally investigates the amount of cooling and evaporation of the direct evaporative cooling system under 5 different angles of placement of the cellulose pad in relation to the vertical position. It includes angles of $$0^\circ$$ 0 ∘ , $$5^\circ$$ 5 ∘ , $$10^\circ$$ 10 ∘ , $$15^\circ$$ 15 ∘ , and $$20^\circ$$ 20 ∘ in 5 different air speeds, 2 different inlet water flow rates, 2 inlet air temperatures, and 2 different inlet water temperatures. Results show that the lowest output temperature, highest air relative humidity, highest coefficient of performance (about 12% more than $$0^\circ$$ 0 ∘ ), highest saturation efficiency, and highest evaporation rate are obtained in the case of a $$15^\circ$$ 15 ∘ of cooling pad placement angle.