How Fast Does a Solar Cover Heat a Pool?

One of the most obvious ways to extend your pool season is to heat up the pool. Although pool heaters come in all shapes and sizes, there is another more affordable and environmentally-friendly option to heat up your swimming pool: a solar cover.

Solar covers help heat up a swimming pool naturally by absorbing the sun’s heat and transmitting it to the water. It also helps by trapping the heat underneath the solar cover so that it doesn’t escape during the cool of the night.

If you are contemplating getting a solar pool cover and are keen to learn more about it, read on. In this article, I will help answer some common questions about solar covers.


Main Takeaways

  • The effectiveness of a solar pool cover depends on the type of solar pool cover, weather conditions, and surface coverage.
  • Solar blankets are by far the most effective type of pool cover.
  • Solar pool covers can heat up a pool up to 15 degrees Fahrenheit in the right conditions.
  • Although solar covers can certainly heat pools, they do not work well as replacements for heaters.

How Fast Does a Solar Pool Cover Heat Your Pool Water?

How fast a solar pool cover will heat your pool depends on various factors, including what type of solar cover you have and weather conditions. Due to this, it’s hard to boil it all down to a single answer. However, on average, you can expect a solar pool cover to heat your pool by up to 5 degrees in 12 hours.

It is important to note that solar pool covers work best alongside another heat source as their main job is to maintain heat by preventing evaporation. On its own, it won’t be as effective, if at all. To get a better idea of how fast a solar cover works, I will detail factors determining how quickly these solar covers heat pools.

Type of Solar Pool Covers

There are three types of solar pool covers: solar blankets, solar rings, and liquid solar covers. Although all three types are effective, the degree of effectiveness differs.

Solar Blankets

Solar blankets are often called bubble solar covers due to their similarity in appearance to bubble wrap. They are made up of little thermal bubbles that cover the entire surface of the cover. The bubbles help capture UV rays and retain heat and moisture in your water. It is an effective and inexpensive method of keeping your water warm by preventing evaporation.

A pro tip for purchasing a solar blanket is to buy one that is slightly bigger than your pool. This way, you can leave some room for error, and you can even trim it at home to fit your pool better if needed. Also, find out the right way to face your solar blanket so you don’t overheat it and cause malfunctions.

These blankets work well to heat your pool and cover the entire surface area. Among the three types of solar covers, solar blankets are the most effective, but the issue is that they are a lot more cumbersome to deal with.

Solar Rings

Solar rings are a great alternative to solar blankets. They are lightweight, easy to use, and you can use them for any kind of pool. They work much like solar blankets, with the additional design of magnets that help connect them to each other to stay in place.

Although solar rings are easier to install as they are smaller pieces of equipment to deal with, there is an added drawback of uncovered pool areas. Solar rings are effective, but they are not necessarily as efficient as solar blankets due to this one drawback.

Liquid Solar Covers

Liquid solar covers are a modern invention that are the easiest to deal with among the three solar cover choices. You simply need to pour the liquid into the pool, and it creates an invisible and non-toxic barrier that stops heat from escaping the pool. Unlike solar blankets and solar rings, liquid solar covers cannot help heat up the pool but will instead work to keep the pool warm. This makes liquid solar covers 20-40% less effective than a solid cover.

However, these are an excellent alternative for those looking for an easy solution to stop the heat from evaporating the pool water. There’s also the added plus of not dealing with a physical cover that you will need to place and remove. You can even swim in the pool with the liquid inside.

Weather Conditions

The weather will also play a big part in the effectiveness of a solar pool cover. As mentioned, solar covers do not work alone; they should not be used as a primary source to heat up your pool. They require another heating source to work more effectively, either the sun or a pool heater.

If you are relying on the sun to heat up your pool, it makes sense that the more sun your swimming pool is exposed to, the faster your pool will heat up. For example, a pool entirely covered by a solar blanket and gets at least 6 hours of direct sunlight may heat up even up to 10 degrees in a single day.

Alternatively, even if you use a pool cover for one week straight under cloudy skies, there’s a high chance that your pool may have heated up just a couple of degrees despite constant use.

Another thing to keep in mind is the night temperature. Most water evaporation happens in the cool of the night, so the cooler the night is, the less effective the solar pool cover will be at reducing heat loss.

Surface Coverage

Part of the reason a solar blanket is more effective than a solar ring or a liquid solar cover is due to the amount of surface coverage. The more the solar cover covers, the better it will be at heating and at heat retention. Even if you couple your solar cover with a pool heater, your pool will only lose the precious heat by heat-robbing winds and cool air temperatures if it is not effectively covered.

How Much Warmer Can a Solar Cover Make Your Pool?

A solar pool cover can certainly warm up your pool, but how much warmer it makes it depends on many factors. Most notably, it must be mentioned that not all solar pool covers can heat up a pool. Liquid solar covers are ineffective at heating pools and are instead used for heat retention. On the other hand, a solar blanket is the most effective solar cover type for heating up a swimming pool.

Depending on the weather, a solar blanket can heat up a pool even up to 10-15 degrees Fahrenheit in a single day. However, on cool, cloudy days, a solar cover will not be as effective at warming up the pool. On average, expect about a 5-degree increase within the first day.

For more information on use cases, read my article on how to use every type of solar pool cover.

Can a Solar Cover Be a Replacement For a Solar Pool Heater?

As a general rule, solar covers are used with a heating system like a solar pool heater. However, solar pool heaters can get quite pricey. So if you are looking for an environmentally and budget-friendly option to heat up your pool effectively, simply having a solar cover could be a potential option in the right circumstances.

The only caveat is that solar pool covers should not be used as heaters. Although they can certainly be used to heat the pool, their primary role is to prevent heat from escaping via evaporation. So if you plan to use a solar cover as a replacement for a solar heater, keep in mind that it won’t be as effective. But if you live in a warmer state, you may not need to purchase an expensive solar pool heater, so using a solar cover could be a great money-saving option.

For recommendations on which one to get, head over to my top picks for the best solar pool covers. And make sure to keep your solar covers clean!

Questions? Drop me a line.

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