Pools lose energy in many ways, but evaporation is the biggest source of energy loss. Evaporation of water requires a lot of energy.
Covering the pool when not in use is the most effective way to reduce pool heating costs. Savings of 50% -70% are possible.
Indoor high-quality automatic pool covers can not only reduce evaporation, but also reduce the need for indoor air ventilation and replace it with outdoor air unconditionally. You can also turn off the fans when the indoor pool is closed, which will save even more energy.
Pool covers should be used during your swimming season. If you use the pool during the day, remove the cover right before swimming and replace it when you no longer use the pool.
If you only use your pool at night, the effectiveness of the pool roof will depend on whether the evaporation and other losses prevented by the cover outweigh the reduction in sun gain caused by the cover. The type of cover and climate influence this balance.
In dry and / or windy conditions, the evaporation rate of the pond increases. So it is usually very helpful to have a clear cover during the day. Evaporation rate decreases in warm and humid conditions. In this case, it may be more profitable to leave the lid open during the day.