How Many Panels & Which Brand Is Best?

How To Size Your Solar Pool Heating System:

  1. 1. Determine Your Pool’s Total Surface Area

Solar pool heating systems are sized based on the surface area of your pool. If your pool is a kidney or freeform shape, this calculation can be a little more difficult.

Surface Area Formulas (Regular Shapes)
Circular: πr² (radius being half the diameter of your pool, π=3.14)
Rectangular: L x W
Size with Google Maps:

  1. Type your address into the search bar and hit enter.
  2. Click the small image labeled “Satellite” in the lower left-hand corner of the map.
  3. Zoom into your address with either the mouse wheel or the (+/-) buttons located in the lower right-hand corner.
  4. Right-click on any portion of the border of your pool. Click “Measure distance”
  5. Continue to click on multiple points, essentially creating an outline of the diameter of your pool, clicking every time the direction changes (you’re essentially creating an outline around the pool with each click of the mouse).
    1. You can move a selected point by clicking on the node, holding the mouse button, and moving it to the desired location.
    2. You can erase and start over by right clicking anywhere on the screen and hitting “clear measurement”.
  6. Once you have gotten all the way around your pool, make a final click on the very first node you made, thus completing the border. When you make this final click, the bottom of your screen will show the “total area” of your pool. This is the surface area of your pool you will use to calculate your solar system size 

Google Maps Example Pool Measurement

*This tool also works well for measuring available roof space
(Satellite imaging provides pretty accurate measurements; however, they are not always 100% accurate and roof measurements should always be double checked.)

2. Calculate Needed Solar Coverage

Expressed as a percentage of your pool’s total surface area.

“50% coverage” means you are matching 50% of your pool’s surface area to solar collectors (panels).

If your pool has a total surface area of 400 square feet, 50% coverage means you will need a total of 200 square feet of solar collectors (panels) to heat it.

  • IE: A 4×12 solar panel has a total surface area of 48 square feet. If six of these panels are used, the total solar collector coverage is 6×48, or 288 square feet.

Coverage Considerations:
Summer months - 50% solar collector coverage should do just fine. If you are looking to extend your swimming season into the shoulder months of summer, look to achieve between 60-80% solar collector coverage. If you are looking for a full extension into the spring and fall, you will want to achieve a solar collector coverage of 80 to 100%.

  • Harsh Winter Conditions:
    Not all climate zones are able to achieve a full spring / fall extension due to the harsh winter conditions. Solar systems do need to be winterized (drained and shut down) for the winter months. For this reason, if you are only able to keep your system running for 6 months out of the year, 60-80% should be enough for most circumstances.

*Solar pool heating systems are dependent on weather and sunlight. As such, these figures can only be used as estimations and cannot be taken as a guarantee.

  • Example 1
  • Example 2

Pool Size: 15 ft. x 30 ft. = 450 sq. ft. (pool surface area)

  • Recommended Solar System:
    • Between 225 & 450 square feet of solar collector coverage (between 50%-100% of pool surface area)
  • With 4' x 12.5' solar panels (50 sq. ft. each)
    • Between 5 and 9 panels would be recommended to heat a 450 sq. ft. pool and provide 4-10 months of warm water (the higher the collector square footage, the longer the swimming season).
  • With 4' x 10.5' solar panels (42 sq. ft. each)
    • Between 6 and 11 panels would be recommended.

Pool Size: 16 ft. x 40 ft. = 640 sq. ft. (pool surface area)

  • Recommended System Size:
    • Between 320 & 640 square feet of solar collector coverage (between 50%-100% of pool surface area)
  • With 4' x 12.5' panels (50 sq. ft. each)
    • Between 7 and 13 panels would be recommended to heat an 640 sq. ft. pool and provide 4-10 months of warm water (the higher the collector square footage, the longer the swimming season).
  • With 4' x 10.5' panels (42 sq. ft. each)
    • Between 8 and 15 panels would be recommended.

Which Solar Pool Heating Panel?
Learn from the Experts


Having trouble deciding which system to select, what the differences are, or which one is the best?
Let’s dive in!

The first part you’ll want to identify is your ideal panel style.
Solar pool heating panels are available in a few different variations; solid body, separated tube, and glazed.
Solid body panels are constructed so that each riser tube is connected to its adjacent riser tube.
Separated tube designs are constructed so that each rise tube is separated from the others (also know as an individual tube design).
Glazed panels contain a special glazing material that encapsulates the riser tubes.

Which is best suited for your needs is primarily based on two factors:

    1. 1. Climate Conditions (main concern here is amount/frequency of wind).
    2. 2. Roof Type

Separated tube designs are ideal for climates with low wind, or areas with extremely harsh winters. This is because separated tube designs generally have higher flow rates than solid body panels (more water/min through the panel) and will result in higher performance ratings when no wind is present to strip any heat. Because separated tubes allow air through each riser tube, these designs do incur a higher rate of heat loss from the wind than solid body or glazed panel designs.
Separated tube designs do generally also have much thicker riser tubes then do solid body panels, making them ideal for areas with harsh winter conditions (thicker riser tubes are less susceptible to freeze damage in cold climates). These systems do still need to be winterized properly, however are more resistant to this type of damage.
Solid body panels are an ideal selection if you live in an area that receives moderate or frequent wind. This is because wind is a primary source of heat loss for solar pool heaters as the air passing through each collector strips some of the heat it generates. Solid body panels incur far less of this heat loss than separated tube designs as the air is not allowed between each riser tube.

Climate Recommendations by Brand:

Minimal or No Wind

A separated-tube design will give you the best performance. Recommended: SwimJoy | Heliocol

Mild to Moderate Wind

A solid body design will give you the best performance. Recommended: FAFCO | SwimEasy

Moderate to Heavy Wind

A glazed (insulated) design will give you the best performance (ideal coastal & cloudy climates). Recommended: SwimLux

Complete D.I.Y. System Kits

Take the guess work out with one of our DIY system kits. Each kit contains everything you need.

  • Install your chosen number of solar panels in a single row. *If the system is being broken-up into multiple rows, one additional row kit will be required for each added row. Please contact us if you need assistance with multi-bank / custom systems.
  • Mount solar panels to your preferred installation surface; roof or rack.
  • Make water connections to and from each panel.
    • Make water connections to your supply and return plumbing lines.
    • Allow for gravity drainage of the panels and piping when the pump is turned off (water drains back to your pool through the supply plumbing line).


*For a complete breakdown of the all the components included in each DIY system kit, see the product or brand description.

What Parts are Included in the Kit?

The following installation hardware is included in our D.I.Y. kits. The row kit, panel kits, and vacuum relief valve are always included while hold down strap is only included with systems requiring strapping.

Panel Kit

  • Contains the parts necessary for installing a solar pool panel to a supporting surface and making water connections from one panel to another.
  • (1) panel kit is included for each solar panel.

Row Kit

  • Contains the parts necessary to connect the feed and return plumbing lines and cap the opposing ends within a single row of solar pool heating panels.
  • (1) row kit is included for each system.

Vacuum Relief Valve

  • Contains the parts necessary to aid in gravity drainage of the panels and piping. Vacuum relief valves allow air to enter the solar pool heating system when the pool pump is turned off and facilitate water drainage from the panels. This is especially important when winterizing your panels to prevent freeze damage.
  • (1) vacuum relief valve is included for each system.

Hold Down Strap

  • Fastens solar pool panels to a supporting surface (roof or rack) and keeps them secure.
  • For normal wind environments; two (2) straps are recommended per panel. For higher wind environments; between three (3) and four (4) straps are recommended per panel.

*Tie down strap is only required/included for the SwimEasy and Fafco DIY kits. Heliocol, SwimJoy and SwimLux feature strapless mounting systems.

Which Size System Do I Need?

The most relevant aspect of sizing a system is based on the square footage of your pool. We typically recommend anywhere from 50%-100% solar panel to pool square foot coverage based on a number of different variables including, weather, shade, install direction, wind, climate region, performance expectations, etc. For example, if your pool is 500 square feet, then 50% coverage would be 250 square feet of panels, 75% coverage would be 375 square feet of panels, etc. From there it is selecting a panel size that fits your installation area.

To find out precisely what size system (how many panels) will adequately heat your pool and provide the results your looks for, see our page on "How to Size Your System". All the factors are discussed and we will help you identify the best system for your pool, climate zone & heating goals.