As pool owners know, heating a swimming pool can consume a lot of energy and add up to high heating bills. But very few ever stop to think about why it costs so much to heat a pool, or for that matter how to reduce heat loss. It all has to do with a little thing called evaporation. Remember learning about evaporation in science class? It’s the process in which a liquid—your pool’s warm, cozy water—is changed into a vapor, and then poof—it’s gone. Simply put, it’s a huge energy guzzler. And all that energy from the gas and electricity used to heat the water gets expensive to replace.
In fact, almost all of a pool’s heat loss—about 90 percent—occurs at the surface, mostly through evaporation to the air and radiation to the sky.1 So what’s a pool-lover like you to do to prevent all that warm water and hard-earned money from vanishing into thin air? Enter the humble pool cover. Pool covers significantly minimize evaporation, so much so that covering a pool when it’s not in use is the single most effective means of reducing pool heating costs, and can lead to savings of 50%–70%.2
The proper selection of a pool cover is one of the most important factors contributing to the increased efficiency of your pool. So choose wisely. Some things to consider include the size and shape of your pool, the conditions and climate in which it will be used, as well as available storage space. You can select from automatic and manual covers. Cover materials vary from UV-stabilized polyethylene, polypropylene or vinyl. They can be transparent or opaque. Covers can even be light or dark colored.
One of the most popular and most affordable covers made is the bubble (or solar) cover. Solar pool covers are made of thick plastic material with UV inhibitors, and they look similar to bubble packaging material. Like other covers, solar pool covers also minimize evaporation, keep out debris, and reduce chemical consumption, but they also help heat the water of your pool, and by keeping your water temperature up you decrease the workload of your pool heating sources. That’s a win-win.
In addition to adding a pool cover, there are a few other things to consider that will help keep the cost of heating your pool to a minimum and still allow you to enjoy comfortable water temperatures. For instance, if you’re planning a new pool think about locating your pool in the sunniest part of your yard to make optimal use of the sun’s solar energy. And since wind both lowers water temperatures and increases evaporation, screening your pool with a windbreak, such as a solidly built fence, is always a good idea.
Whatever water temperature you desire for your swimming pool, be sure to utilize the evaporation-reducing and cost-saving benefits of a pool cover. You’ll spend a lot more time enjoying your pool and a lot less time (and money) heating it.