Energy Loss in Pools – Part 1 – How Much A Pool Evaporates? How To Prevent It?

In Blog by TMI Sustainable Aquatics

This blog was brought to you by our friend Cory Willis.  

Pools lose energy in a variety of ways! Did you know evaporation is by far the largest source of energy loss for swimming pools? When compared to evaporation, all other losses are small. The reason evaporation has such an impact is that evaporating water requires tremendous amounts of energy. It only takes 1 Btu to raise 1 pound of water 1 degree, but each pound of 80 degree water that evaporates takes a whopping 1048 Btu’s of heat out of the pool.

However, evaporation has another effect that figures into your current concerns in this water conservation/drought conditions. In some areas the evaporation rates estimated that the entire volume of the pool, in gallons, is the amount of water evaporating and needing to be replaced in a year’s period of time.

The evaporation rate from an outdoor pool varies depending on the temperature of the pool, the temperature and humidity of the air, and the wind speed at the pool surface. The higher the pool temperature and wind speed and the lower the humidity, the greater the evaporation rate.

Stay tuned for our next blog on how to deal with the energy loss in pools!