Solar Pool Heater

A solar pool heater does exactly what its name suggests; it keeps your swimming pool heated through the power of solar energy.
Photo credit: Department of Energy

It is a great alternative to a gas-powered heater for your pool and is also considered environmentally safe. Unlike normal solar panels that turn the ray of the sun into electricity, these pool heaters use the energy directly. In the long run, this may save you more money as opposed to other heating systems.

How Exactly Does It Work?

The water from the pool is pumped into a solar hot water collector. Normally, the solar water collectors are located on the roof where the liquid is heated naturally by the sun as it runs through each of the thin pipes. This system can also be used to cool down the temperature of the pool if left running during the night hours. The system also includes a filter, which is used to remove any debris that may be present in the water before pumping it into the pool, a flow control valve that automatically or manually controls the water level that is being diverted, and a pump that circulates the water through the filter collector and back to the pool. Solar pool collectors come in many different material forms. The best one for you is based on the climate and the amount of sunlight in the area in which the pool is located.

Free LEED Exam PreperationAn unglazed collector system is used in climates where the average temperature is typically above freezing. This type of collector does not include a glass covering. It is made of rubber or plastic treated with a UV light inhibitor in order to increase the life of the panels. These unglazed collectors are usually less expensive because of the low cost of the parts and the simplicity of the design. This system can also be used indoors in colder climates only if it is designed to drain the water back to the pool whenever it is not in use. These collectors can be more cost efficient as opposed to a more expensive glazed system.

Glazed collector systems are made of copper tubing on an aluminum plate with an iron-tempered glass covering. This metal material is what makes it cost more. This system can be used all year round and may be best for areas that have colder weather. It can also be used to heat domestic hot water during the entire year.

How Much Does It Cost?

A solar pool heating system can cost anywhere from $3,000 to $4,000. This price includes installation. The exact price is determined by the type of system you choose and the location of installation. Other factors also include the site’s solar resource and the size of the pool. Before purchasing, it is best to compare the prices of several systems and contractors. Also it is good to look in to your areas local codes, covenants, and regulations.

The solar resource is considered one of the main components in using the system to its fullest capability. Solar pool heating systems can use direct and diffuse solar radiation. If your location generally faces the south it may still be a candidate for a heating system. Always consult a professional when trying to determine this information.

Determining the exact size of the heating system will require the following information: the size of the pool, the average temperature of the area, the collector efficiency, the collector orientation and tilt, site’s solar resource, and the length of the swimming season. The surface area of the collector should be about 50% to 100% of the surface area of the pool. The colder the area (and the lack of sunlight) the more you may need to increase the ratio of the collector area and the pool surface area. If a pool cover is added, the area size of the collector can be decreased.

Where to Site the Solar Pool System

A solar pool heater can be placed on a roof or any location that is near the swimming pool. Whereever its location, it must have the proper exposure, orientation, and tilt towards the sun. These factors are extremely important and will have a direct effect on the performance of your system.

The collector should be geographically oriented to increase the amount of solar energy it will receive. In the northern hemisphere it is said the best orientation for collector is true south. The tilt of the collector depends on the latitude and length of the season in which you plan to use the pool. If you are looking to only have your pool heated during the summer, the tilt should be angled to equal you latitude minus 10º–15º. For heating through-out the year, it is best to tilt the angle equal to your latitude.

Efficiency of Solar Swimming

If available, you can find out the efficiency of your solar pool system based on the collector’s thermal performance rating. The rating is measured by British thermal unit per square foot per day, or Btu/(ft2day). Alternatively, it can be measured in megajoules (MJ) per square meter per day: MJ/(M2day).


If installed properly, your system should be able to run smoothly for up to 20 years. The system will require maintenance, which should come detailed in the owner’s manual. Also, consult the contractor who installed the system for any extra information on how to care for your new system. Make sure to check the pool’s chemical balance and filtering system on a regular basis. Glazed collector systems may need to be cleaned in drier climates is no rain water is present.


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