Performance of Evaporative Cooling Pads Made from Different Plant Materials of Sub-Saharan Area

Abstract

A thermal comfort zone is sought by all living beings for their optimum life activity, production or reproduction. In hot environment, direct evaporative coolers are often used as cost-effective thermal comfort providing-devices. This paper presents performance analysis of newly proposed accessible and cost-effective evaporative cooling pads from local plant materials (herbs and fibers) from Niger, a sub-Saharan country. Experiment was run in an experimental duct exposed to ambient pressure and temperature conditions, with different fan speed (5.11 and 5.52 m/s) and constant pad thickness (5 cm). Saturation efficiencies, mass and heat transfer coefficients, pressure drop, permeability, increase in relative humidity as well as coefficient of performances (COP) and cost-to-efficiency ratios (CER) were obtained for all the pads locally made. Compared to commercially available Celdek pad with tested efficiency of 70.02% and 79.80% at low and high fan speed respectively, local pads efficiencies ranged from 16.50% to 69.88% at a frontal velocity of 5.11m/s and from 22.73% to 78.80% at 5.52 m/s frontal velocity. Most of the local pads had better CER than the commercial one. Pad made from local wood wool emerged to be an excellent candidate providing thermal comfort and outlet temperature close to that of commercial pads. Controlling physical parameters such as arrangement, flute size and packing pattern can help to improve some of thermodynamic properties of locally made pads