Overview

Outdoor swimming pools are big energy consumers. Pool owner/operators spend billions of dollars annually to heat the nation's pools. Much of this energy is often wasted and can be saved with proper management. Wasting energy also contributes to our growing air quality problem.  There are three pages to the fact sheet so be sure you read them all.

Page 1 | Page 2 | Page 3

HOW POOLS LOSE HEAT

Pools lose energy in a variety of ways, but 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 water that evaporates takes a whopping 1048 Btu's of heat out of the pool.

The following diagram illustrates the impact of evaporation on the total energy consumption of the outdoor pool.

MINIMIZE EVAPORATION 

Since evaporation is the major source of heat loss for swimming pools, to minimize evaporation, one must cover the pool. Covering your pool when it's not in use is the single most effective way of reducing pool heating costs. Savings of 50-70% are possible.

There are many energy management improvements that can be implemented with outdoor pools.

POOL COVERS

Below are three types of pool covers. Refer to the fact sheet on pool covers for more detailed information.

Pool covers also provide many other benefits besides saving energy. They conserve make-up water by 30-50% and can reduce chemical consumption. Cleaning time is cut by preventing dirt and other debris from entering the pool.

It is highly recommended that the first step to cutting pool energy loss be the evaluation of the economics of using a swimming pool cover.

Covers must be managed properly for safety. They should always be completely removed before anyone enters the pool.

WIND BREAKS

One item that can greatly increase evaporation from outdoor pools is wind blowing over the pool. A 7 mph wind at the surface of the pool can increase energy consumption by 300%. Adding trees, shrubs, fences, or other wind break material can significantly lower the heat loss from the pool while it's open.

Pool covers are great at stopping evaporation when the pool is closed, but can't do anything to cut evaporation when the pool is open.

The windbreak needs to be high enough and close enough to the pool that it doesn't create turbulence over the pool and increase evaporation, but try not to block the sun from shining on the pool.