Improved method for calculating evaporation from indoor water pools

The author had earlier published a formula for calculating evaporation from unoccupied indoor swimming pools and other water pools. The formula was derived from the analogy between heat and mass transfer during natural convection. It was shown to be in good agreement with all published test data. However, it was applicable only to positive density difference (i.e. when the density of room air was greater than that of air at the pool surface). The methodology has now been extended to apply to negative density differences. The extended calculation method has been validated with all available test data. This paper presents the improved method and its comparison with data from eleven sources. All data are predicted with a mean deviation of 14.5%. Thus this method can be confidently used for swimming pools as well as other pools with quiet water surface.

► A method of calculating evaporation from swimming pools is presented.
► It is derived from analogy between heat and mass transfer.
► It shows excellent agreement with all published data.
► Its accuracy is far better than presently used methods.