Every pool owner knows it’s essential to cover a pool when it’s closed during the winter months. But what about during the swim season—is it still necessary to cover your pool when it’s not being used, or is it just more hassle than its worth?
The most obvious benefit of using a cover is that it keeps your pool cleaner, with less effort on your part. A cover protects your pool from leaves and other debris that would otherwise end up in your filtration system or have to be skimmed out by you. Less time spent cleaning means more time spent enjoying your pool. Automatic cover systems have come down in price in recent years, and having a hassle-free cover solution may be worth the investment to some pool owners. Most automatic covers are designed to prevent a child or pet from falling through into the pool, increasing the safety of your pool area and giving you peace of mind.
It seems most pool owners choose to forgo the more expensive automatic cover in lieu of a portable cover which is pulled on and off. You’ve seen them in the stores, and maybe even used them. Those transparent “solar covers” that look like a giant sheet of bubble wrap, or the newer “solar ring.” These types of covers may claim to heat your pool water, since it allows the sun’s natural light to pass through them. In reality, these covers don’t actually add much heat to the pool (at least beyond the first 1″ underneath the cover), though they do help keep a pool warm by retaining any existing heat.
Swimming pools lose most of their heat—up to 75%— through evaporation, particularly at night. You might look at the photo to the right and think it looks warm and inviting. We look at it and see dollar signs evaporating into thin air.
Evaporative heat loss is affected by wind speed across the pool surface, as well as humidity levels of the air. A cover helps to retain heat in a pool by shielding the pool surface, much in the way a cup of coffee stays hotter longer when a lid is used.
Owners of fossil-fuel heaters, such as gas or electric pool heaters, will want to make sure every last bit of heat stays in the pool, since they’re paying a premium to keep it at that comfortable temperature. The main advantage of installing a solar pool heater, however, is that once installed, there is no cost to heat your pool. This may lead to some solar pool heating system owners being a bit more relaxed about using their cover all of the time, if at all.
So, in regards to using a cover with a solar pool heater: though it may not be necessary, it does go a long way toward keeping all that hard-earned solar heat where you want it—in the pool!