By Andrew Kehl June 27, 2023

Solar Pool Heaters for Inground Pools: Efficient & Green

You love your inground pool, but can’t get as much use out of it as you’d like. The water is cold much of the year, and that’s a shame. You’re paying for the pool’s upkeep and maintenance, without getting to use it on days that might otherwise be warm enough.

There’s an easy solution to this problem: a solar heater for your inground pool.

A solar pool heater is a product that uses heat from the sun to warm the water in your pool. Solar pool heating systems use this natural energy to keep your pool warm and comfortable for a much longer period throughout the year. Solar pool heating is a simple and energy efficient way to get the most use out of your pool possible.

There are many benefits of using solar pool heating systems, including:

Raise the value of your property. Your solar pool heater can make your swimming pool (and potentially your home) more valuable to buyers, should you decide to sell.
Low-maintenance. Solar heaters are low-maintenance products that require little upkeep or maintenance throughout the year.
Low-cost. Solar energy is free, so the costs to run and maintain your solar heater is very low, after making the initial purchase.
DIY-friendly. You can install your own pool solar heater rather than hiring a contractor to do the work for you. This minimizes the initial cost to purchase your unit, and makes this type of heater more attainable if you’re on a budget.
Flexible. Adding extra parts and hardware to the DIY installation kit, you can customize your heater to meet your pool’s unique needs.

In this article, we’ll talk about the pros and cons of solar pool heaters and discuss why Solar Pool Supply is a leading supplier of solar heaters for inground swimming pools. By the end of this article, you should have all the information you need to make an informed decision about your pool heater.

How Do Solar Pool Heaters for Inground Pools Work?

While details may vary from one solar pool heating system to the next, most solar pool heaters work about the same. Below is a general idea of how solar panel pool heaters heat your home’s pool water.

The solar collectors (panels) are located on either the roof of your home, nearby roof, or somewhere on your property near your swimming pool. These panels are made up of black tubes that fill with water and heat up in the daylight.

The pump and filter system keeps the water cleanly flowing through the collector, always refreshing the water in the collector. This allows water that has been heated to return to the swimming pool, while water that is unheated flows into the collector to be warmed.

Solar pool heating systems can be controlled either manually, by way of a 3-way diverter valve, or automatically, by way of an automation controller. Automation systems monitor the temperature of the water to ensure that it reaches the desired temperature. Once the water has reached the desired temperature, the flow control valve system keeps the water at that temperature for as long as possible. Manual control is accomplished by simply turning a 3-way valve, turning solar on or off as desired.

Compared to other types of pool heaters, which usually need to be installed by a professional and also incur an ongoing utility cost, solar pool heaters are easy to install, inexpensive to run, easy to maintain and affordable. They have many of the advantages of other pool heaters and few of the downsides. Ultimately, solar pool heaters can help you get more use out of your inground pool.

Want to see how easy a solar pool heater can be installed? Check out the video below where we walk you through the entire installation process, step-by-step!

Choosing the Right Size Solar Pool Heater for Your Inground Pool

The best way to ensure that your solar pool heater for your inground pool will be effective is to build a system that’s the right size for your pool.

When you’re evaluating how big your pool heater should be, consider these factors:

Pool surface area. Your pool loses most of its heat at the surface, therefore, this is the only size that needs to be considered when you’re choosing a heater.
Climate where you live. Cold climates can reduce the effectiveness of your solar pool heater. In locations where outdoor temperatures tend to be cool or cold for much of the year, you’ll want to look into a slightly larger system if your goal is to extend your swimming season into the spring and fall (more than summer heating). The additional solar coverage will help when outside temperatures are lower, and sunlight availability is diminished.

The offset determines how long you can extend the swim season. A 50% offset will ensure 3 to 4 months of pool heat and warm swimming temperatures. This heats ground swimming pools and your pool throughout the summer and may extend the swim season by a few weeks on either side of the summer. A 100% offset can extend the swimming season through the later months of fall and early months of spring, if your climate is favorable.

The offset is determined by the size of the solar panels compared to the size of the pool itself. If the solar panels are 50% of the surface area of the pool, then this is a 50% offset. If the solar panels are 80% of the surface area of the pool, this is an 80% offset.

How to calculate the surface area of your pool:

Circular: πr² (radius being half the diameter of your pool, π=3.14)
Rectangular: L x W (length x width)

how to determine the right size solar pool heaters

Google Maps can also help you measure the surface area of your pool. This is useful if you have a pool that’s an unusual shape.

For step by step instructions using this tool, see the page: “BUYER'S GUIDE: How Many Panels Do I Need?”: https://www.solarpoolsupply.com/pages/how-many-solar-panels-do-i-need

Even with the help of Google Maps and the right calculations, choosing the right offset for your climate can be a challenge. Knowing your goals for your solar heater can help you decide what size is best, but before you invest in a solar heating system for your pool, consider checking with the customer service experts at Solar Pool Supply to choose the best size system for your pool.

Solar Pool Supply has a page entirely devoted to helping you select not only the correct size for your heating goals, but also the correct brand for your home's unique needs, as well as the climate you live in, all factors that play a role in the perfect system for you.

CLICK HERE FOR A FULL SIZING & SELECTION WALK THROUGH

Frequently Asked Questions About Solar Pool Heaters for Inground Pools

Can solar pool heaters work in cold climates?

Solar pool heaters can work in cold climates. However, in a cold environment, solar pool heaters may require a larger offset than they would in warm climates, and if the climate is cold enough, the pool heater may extend the swim season for less time. To find a pool heater that helps you achieve your goals for your swimming pool, know how many months you’d like to extend your swim season, and use this to calculate your offset. If you’re not sure whether your pool heater of choice will help you reach your goals, contact Solar Pool Supply’s customer service to get more direction on how to build the right system for your pool.

How long does it take to heat a pool with a solar pool heater?

The answer to this question depends on many things.

How warm do you want your pool to be?
What is the temperature of the pool before heating?
What time of year is it?
Are you using a solar cover?
How large is your pool?
How big is your heating system?
Is it sunny outside?

In other words, it’s very hard to say how long it will take for your pool to heat up once the solar pool heating system is installed. You can start to notice a difference before the end of the first day, but some systems under some conditions may take a whole week to fully warm the pool water temperature up.

Can I use a solar pool heating system in conjunction with another type of pool heater?

There is nothing that prevents you from using another type of pool heater with your solar pool heater. For example, you may choose to install a heat pump pool heater to supplement the work of your solar pool heater. These two heaters will work together to heat your pool faster and more effectively. Using solar as a pre-heater will help to dramatically reduce the operational cost of any supplemental heating system that is used, as you’ll be running it for less often, and for much shorter durations with solar helping to keep the initial temperatures warmer.

How much maintenance do solar pool heaters require?

Solar pool heaters require little maintenance beyond the usual winterizing of the system. Your solar pool heating system will need to be winterized and isolated when temperatures outside drop to 42 degrees. Follow all system maintenance recommendations in your pool’s installation manual.

Installation and Maintenance of Solar Pool Heaters for Inground Pools

Selecting a site for your inground solar pool heater is important. Select the site before buying the system. This will help you create a plan for your solar system itself, and will help you decide how much space you have for your array of solar pool heating panels. You can install your solar panels on a flat patch of land, or on your home’s roof. Choose the location based on what fits on your roof space and what you can safely reach during the installation process.

Once the boxes with the DIY pool solar heater kit arrives, unpack the boxes to find the installation instructions. Review the instructions to ensure that you have all necessary tools to perform installation. The solar panels will be installed first. Once this is done, then you’ll install the plumbing. You may need items including a caulk gun, ladder, hacksaw and basic hand tools. If you’re performing installation on your roof, you’ll also need adequate fall protection.

Read the instructions from start to finish before starting installation. If you need them, installation instructions can be found on the Solar Pool Supply website. If you have questions about installation, contact Solar Pool Supply’s customer service.

Once the system is installed, it will require little maintenance. Plan to winterize the system at the end of the season. If you’re ever backwashing the filter or adding diatomaceous earth, disconnect the collectors to keep them free of buildup and clogs.

Comparing Solar Pool Heaters to Other Types of Pool Heaters

Generally speaking, there is not a lot of initial cost difference between a solar swimming pool heater and another type of pool heater. Typical equipment costs are as follows:

Electric pool heater - $2,000 to $5,000
Gas or propane heater - $2,000 to $4,000
Heat pump - $2,000 to $5,000
Solar - $3,000 to $4,000

However, there are some important differences to keep in mind. First, solar pool heaters are DIY-friendly, so a budget-conscious homeowner can avoid the installation costs altogether. Second, solar pool heaters are virtually free to run. This is a notable difference between a solar pool heater and a pool heater that uses a home’s utilities (gas or electric) to run.

Compared to gas and electric pool heater products, solar pool heaters are the most energy efficient heaters on the market. This is because solar pool heaters use the actual energy from the sun to heat the water, instead of using the utilities in your home to accomplish the same goals. The environmental impact of solar heaters is also comparatively low, which means that you can enjoy a warm pool while also knowing that you’re doing your part to minimize harm to the environment. When comparing the solar pool heater you're interested in to other solar pool heaters on the market, most well made products generally have similar efficiencies, so you're guaranteed to be helping the environment regardless of which option you go with.

Type of Pool Heater	Cost	Environmental Impact	Maintenance	Energy Efficiency	Lifespan
Solar Pool Heater	$$	Low	Low	High	10-20 years
Gas Pool Heater	$$$	Moderate	High	Moderate	5-10 years
Electric Pool Heater	$$$	High	High	Low	5-10 years

Solar Pool Heater Accessories

There are many potential accessories that can be installed and enjoyed along with your solar pool heater.

Pool cover. The primary function of a pool cover is to prevent dirt and debris from entering the pool. Pool covers can help trap some heat in the pool, but it is not their primary function. Pool covers help keep your water cleaner and allow you to jump in the pool faster when it’s time to swim. Using a pool cover may also extend the life of your pool filter.

Solar blanket. A solar blanket is a pool cover with an added benefit: it traps in heat and keeps the pool even warmer by an average of 10 to 15 degrees fahrenheit. Solar blankets help prevent evaporation in ground pools and use sun rays to heat the surface of the pool. When combined with a solar pool heater, the solar blanket can help ensure a warm and comfortable swim season for a longer period of time.

Solar pool heaters and solar blankets work extremely well in tandem if you're looking to maximize how long you can extend your swimming season (or if you live in a colder climate and want to maximize gains). The solar blanket (or cover) will help reduce the amount of heat lost at night, helping your solar collectors further build on gains achieved during the daytime.

Automatic temperature controller. Automatic temperature controllers work with your solar pool heating system to control your pool’s temperature. These systems are programmable and easy to use, and available in digital or analog.

Solar pool lights. Solar pool lights use the energy from the sun's heat, to light your pool. These lights don’t affect the functionality of your pool heater, nor do they take away energy from the pool heater. They work separately from the heater to make your swim experience more pleasant and enjoyable at night. There are a variety of different types of solar pool lights, shop around to find the product that makes the most sense for your pool.

Investing in a Solar Pool Heater for Your Inground Pool: The Ultimate Way to Save Money and Enjoy Your Pool Year-Round

In the end, your solar pool heater can make your inground pool a more worthwhile investment that the pool owner's entire family can enjoy. There are many benefits of using solar pool heaters to heat your home’s inground pool and extend your swim season.

Add value to your home and your pool.
Improve your comfort while swimming.
Incur few costs after purchase (low cost to run and maintain).
Add weeks or months to your swim season.
Can be installed by you instead of a contractor or handyman.

All these benefits means that installing a solar pool heater in your home is a comparatively easy decision, compared to other upgrades that you might make to your pool. The rewards outweigh the costs by far, and when the work is all finished, you’ll have the pool heater you’ve always wanted to improve your swimming experience.

Want to know more about installing a DIY solar pool heater in your in-ground pool? Work with the customer service team with Solar Pool Supply. Our customer care representatives can help you build a system that will extend your swim season and help you meet your goals for your pool. We can also answer any questions you might have during the installation process. Contact us today.