A unified empirical correlation for evaporation of water at low air velocities

Abstract

This paper presents a simple empirical correlation to predict the rate of water evaporation from small exposed water bodies. The correlation is a function of air velocity and difference between saturated vapour pressure of water body and partial water vapour pressure of the surrounding air. Earlier correlations were valid only for either still air or for minimum air velocities from 0.9 m/s whereas this correlation can predict the rate of water evaporation even from still air to air velocities up to 5.36 m/s. The correlation is particularly relevant to predicting the evaporation rates of defrosted water in domestic refrigerators where the air velocities in home kitchen environment are very low ie. between 0 and 0.9 m/s.