Experimental Study of a Tube Based Indirect Evaporative Air Cooler

Horizontal concentric tubes evaporative cooler has been developed where the use of a pump to continuously wet the fibre evaporative cooling medium was eliminated. Initially 10 different paper-fibre samples were vertically supported in a tank containing water at the base. A suitable paper fibre was then selected for making the tubular evaporative cooling surfaces. The system operates as an indirect evaporative air cooler consisting of dry and wet air flow channels. Experimental results showed that up to 10°C temperature drop between the inlet and outlet of the product (dry channel) air was recorded. For an inlet relative humidity of 10%, the observed outlet values were 53.3% and 88.3% for the dry channel and the wet channel respectively. The dry channel serves as the product or supply air to the building space. In this paper, experimental results and relevant equations were used to evaluate the system effectiveness.