Want to install a solar pool heater but don’t know how many solar panels to use? Here is a complete guide for you.
In addition to warming up your pool and making it comfortable to swim in well past swimming season, installing a solar-powered pool heater is a great way for pool owners to save money on heating costs.
The systems are generally less expensive to install and work, and frequently last longer than conventional gas or electric pool heating systems. Solar pool heaters can be used for both above-ground and in-ground pools, making them versatile and compatible with a variety of pool sizes and types.
The number of solar panels required to heat a pool will be discussed in this blog. And you can learn How Much to Install a Solar Pool Heater.
How Many Solar Panels to Heat a Pool?
As a rule of thumb, you’ll need about 1 square meter per person to give enough hot water in summer. For flat panels, this typically translates to one panel for a small household or two panels for a larger one. Depending on the household and how often you use hot water, you might need 20 or 30 tubes for tube collectors.
Size matters because you typically need a cylinder that is almost twice as large as a typical cylinder. This is due to the fact that a taller cylinder enables you to store more water that has been heated by the sun and satisfy more of your needs. Less backup heating is required because a large cylinder provides more buffer to get you through cloudy spells.
Your installer should determine the size of the panel and cylinder based on your hot water needs. In order to design a system that will meet your needs, they will enquire a few questions regarding your hot water usage.
How Does the Solar Pool Heater Work?
Pool water is first pumped out of the pool and through a filter before going to a solar thermal collector to be heated by the sun before being pumped back into the pool. To regulate the pool temperature, the system also needs a sensor, a flow control valve, and a check valve. Read more information about the principle of solar pool heaters.
Most systems can automatically determine the water’s temperature and move the water to the solar collector, where it will be heated before being returned to the pool. The flow control valve then directs the flow from the solar collector back to the pool once the water reaches the desired temperature.
The solar collector is typically oversized in colder regions of the US and in locations where pools are used year-round, enabling it to continue heating the pool even when there are significant drops in temperature. If necessary, a solar water heater can also be used in conjunction with electric or gas heaters.
Is My Home Suitable for Solar?
The most efficient solar collectors are those with a southeast or southwest-facing angle between 20 and 50 degrees. It only needs to be about 20% bigger for an east or west-facing panel to still be worthwhile.
Solar water heating will be best in a house that has a larger hot water demand – such as for a family or a house-share. It won’t be as cost-effective for a one-person household with minimal hot water usage (and in that case, you might be better off just diverting a portion of the output from a PV array).
A cylinder or tank is required to store solar-heated water, just like with heat pumps and biomass boilers. This means that integrating a combi boiler and solar water heating is difficult. For more information on combi boilers and solar energy, see the related question below.
The most popular type of panels are roof-mounted, and they should be installed to reduce pipe runs to the cylinder. Alternatively, if the panels will have a clear view, you could install them at ground level. Learn How Much Does a Solar Pool Heater Cost?
Solar Thermal Collectors
Solar thermal collectors make use of the thermal energy that the sun’s radiation produces. Cool water is pumped through the collectors at the bottom. The water that has been heated by the sun rises to the surface, where it can be used to warm swimming pools, as well as interior spaces like homes and buildings.
Glazed Vs. Unglazed Solar Thermal Collectors
Solar thermal collectors come in two main varieties: glazed and unglazed.
- Glazed solar collectors
Glazed solar collectors, also referred to as flat-plate collectors, are enclosed in glass and frequently have more intricate designs because they are constructed from metals (such as copper tubing and aluminum plate) underneath an iron-tempered glass covering.
Because they take up less space and can heat water more effectively, these systems can generate more heat. Glazed solar collectors can be used all year round, but they are more expensive than unglazed solar collectors.
- Unglazed solar collectors
These collectors are often made of black plastic or heavy-duty rubber and are ultraviolet (UV) treated to help extend their service life.
Although unglazed solar collectors are frequently less expensive, they are less efficient and only suitable for pools that don’t freeze in colder climates.
Which Size Solar Collector is Right for Your Home?
The Department of Energy (DOE) suggests that the solar collector is between 50% and 100% of the square footage size of the pool’s surface, depending on how many months of the year you intend to use your pool and how warm you prefer your water to be.
For example, if a pool is 15-by-20 feet, it has 300 square feet of surface area. As a result, the solar collector should have a surface area of 150 to 300 square feet.
Consider a solar collector that is the full size of the pool or bigger if you want to keep your pool open all year.
To allow for year-round use, a 15 by the 30-foot outdoor swimming pool in Florida typically needs a collector that is 100% of the pool’s square footage. The collector space is equal to 450 square feet.
Conclusion: How Many Solar Panels to Heat a Pool?
If your pool has a total surface area of 400 square feet, 50% offset means you will need a total of 200 square feet of solar panels to heat it. As a reference; a single 4’x12. 5′ solar panel has a surface area of 50 square feet, so a system with (4) 4’x12. 5′ solar panels have a total surface area of 200 square feet.
As a general rule, we advise 100% coverage, which entails requiring one square foot of solar panels for each square foot of pool surface. From there, we adjust based on additional factors.
How Many Degrees Will a Solar Cover Heat a Pool?
By harnessing the heating powers of the sun, solar pool covers offer the added benefit of raising pool water temperatures by an average of 10 to 15 degrees Fahrenheit. All of this results in solar pool covers saving pool owners time and money. See How Long Does a Solar Cover Take to Heat a Pool?
Is Solar Pool Heater Worth It?
Installing a solar pool heater will significantly lower your heating expenses for swimming pools. They have very low annual operating costs and are cost-competitive with both gas and heat pump pool heaters. Actually, solar pool heating is one of the most cost-effective uses of solar energy in some climates.