Experimental investigation of evaporative cooling using surfaces with low porosities

Abstract EN

This paper presents the results of an experimental investigation to determine the degree of cooling produced by free and assisted evaporation from a porous surface into the surrounding ambient.

It is found that both the porosity of the surface and the relative humidity of the ambient are the two major factors which determine the lowest possible temperature of the surface.

For example, after about three and a half hours the temperature of the surface with 32% porosity drops by 5.3°C, while this drop is 3.1 °C and 1.8 "C for porosities of 27% and 8%, respectively.

As far the relative humidity effect, it is shown that an increase in the relative humidity from 39% to 83% lowers the temperature drop from 6.5°C to 2.4*0.

An empirical relationship is derived and presented to predict the drop in temperature as a function of porosity and relative humidity.