Heat and mass transfer processes between a water spray and ambient air – I. Experimental data

Evaporative cooling of air by water sprays is an energy efficient and environmentally benign technology that can be employed for producing a reasonably comfortable condition in arid climates. Experimental data on this process are limited and often have large uncertainties. This paper presents experimental data obtained for two ambient conditions, viz., hot-dry and hot-humid, covering dry bulb temperature (DBT) from 35 to 47 °C, and R.H. 10–60%. The studies were conducted for parallel and counter flow configurations, each with four nozzle sizes; water pressures were 1, 2 and 3 bar(g) and air velocities 1, 2 and 3 m s −1. The controls on air and water conditions, and the accuracy of measurement were improved so that the uncertainties are considerably lower than in earlier studies. The data showed clear trends. For a specific water flow rate, a smaller nozzle at higher pressure produced more cooling than a larger nozzle at lower pressure.