heating loss in swimming pools

1. Evaporation

Evaporation is the most significant source of heat loss in outdoor pools, accounting for approximately 70% of total heat loss. When water evaporates from the pool surface, it takes a substantial amount of heat energy with it. This process cools the water left in the pool. Several factors influence the rate of evaporation, including:

• Water Temperature

• Air Temperature and Humidity

• Wind

Without a pool cover, this evaporation is constant, leading to significant heat loss, especially at night when temperatures drop.

2. Radiation and UV Sun Rays

Approximately 20% of heat loss in an outdoor pool occurs through radiation and the effects of UV sun rays.

While sunlight can initially warm the pool, it can also contribute to heat loss. UV radiation can break down chemical bonds in the water, which, in turn, releases heat. During the day, the sun heats the pool water, but without proper insulation such as a pool cover, much of this heat is lost when the sun sets.

3. Loss to the Ground

Heat lost to the ground accouts for around 10% of heat loss in outdoor swimming pools. This occurs when heat from the pool water is transferred to the ground and the surrounding pool structure. Several factors influence this process, such as your pool flooring type (eg. concrete)

The design and construction of the pool, including the use of insulation around the pool shell, can mitigate conductive heat loss to some extent. However, for most pools, this remains a small but consistent source of heat loss.

Reducing Heat Loss In Your Pool

To reduce heat loss and maintain a comfortable swimming temperature, many pool owners invest in pool heating systems and covers. Pool covers, in particular, are highly effective in reducing evaporation, while heating systems can compensate for the heat lost from the elements through radiation and ground loss.

Understanding the dynamics of heat loss in outdoor pools helps in making informed decisions about your pool maintenance and heating solutions, ensuring a more enjoyable and energy-efficient swimming experience.