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Vortex Solar Pool Heating System

VORTEX Solar Pool Heating
Automated System Sizing

The Vortex Solar Pool Heater Automated Sizing Calculator will assist you to determine the number of solar panels needed to properly heat your swimming pool.

For additional information on Vortex solar pool heaters please click on any of the links on the right of this page.

STEP 1 - Establish Pool Surface Area

Using a tape measure, determine the pool's overall length and width.

Enter the overall pool width:


Enter the overall pool length:


STEP 2 - Select Pool Shape

Using the Pool Shape chart below, determine the Shape Factor simply by choosing the shape of the pool and the corresponding factor number.

Pool Shape
Pool Shape Factor
Rectangle 1.00
Kidney 0.85
Freeform 0.85
Oval 0.90
Round 0.79

Enter the shape factor number, including decimal point:

STEP 3- Select Roof Orientation

Using a compass, determine the directional orientation of the roof.
Select roof area based on fit, function, appearance, and direction.
Note: A south facing roof area offers optimal efficiency.

Solar panels can face up to 30° East or West of True South for optimum efficiency. Panels can not face in a northerly direction, unless supported by a rack to elevate the system towards south. 

Using the Roof Orientation chart below, determine the Orientation Factor simply by choosing the appropriate roof direction and the corresponding factor number.

Roof Orientation
Direction Factor
South Facing 1.00
East Facing 1.25
West Facing 1.25
Flat Roof* 1.10

*See the Solar Pool Heater Installation Manual [PDF Format] for precautions on installing on a flat roof.

Enter the orientation factor number, including decimal point:

STEP 4 - Establish Pool Shading

Determine the percentage of area and length of time any area of the pool is covered with shade during the Solar Window (9am-5pm). Using the Pool Shading chart below, determine the Shading Factor simply by choosing appropriate percentage and the corresponding factor number.

Pool Shading
Shade Factor
No shade from 9 am - 5 pm 1.00
25% Shade 1.10
50% Shade 1.25
75% Shade 1.50
100% Shade 1.75
Indoor Pool 1.75

If only a portion of the pool is shaded for part of the solar day, then a Shade Multiplier Factor should be extrapolated from the table (i.e. 50% of the pool shaded for 50% (4 hours) of the solar day equals 25% or a multiplier of 1.10). Indoor pools should use 100% shade multiplier.

Enter the shading factor number, including decimal point:

Enter a screen enclosure multiplier:

  • Screen enclosure, use a 1.25 multiplier
  • No screen enclosure, use a 1.00 multiplier

STEP 5 - Establish Desired Swimming Season

Florida Residents - Using the chart below, find your location, then choose the corresponding factor number. If you are located between two numbers, use the average. When in doubt, use the larger number.

Florida Extended Season
Region of Florida 9-10 Month 11-12 Month
North 0.64 0.80
Central 0.56 0.68
South 0.48 0.56


Outside of Florida
- Using the map below, find your location, then choose the corresponding factor number. If you are located between two or more numbers, use the average. When in doubt, use the larger number. (To see the potential swimming season for your area, scroll to the bottom of the page).

Enter the swimming season factor number including the decimal point:

To run the estimator, click the "calculate" button

Scroll down to see results below:

This is the total pool surface area:

sq ft

This is the required square footage of solar panels:

This is number of 4' x 8' solar panels:


This is number of 4' x 10' solar panels:


This is number of 4' x 12' solar panels:

CRITICAL INSTALLATION NOTE: the above system sizing formula is designed assuming the use of a Solar Pool Cover when night time air temperature drops below 60 degrees F. If a cover is not being used during the conditions, then the system MUST be over-sized by 75 - 100% to attain desired water temperatures.

I know how many panels I need, what next? Choose from:

» Standard Kit
Ideal for replacing existing systems, or if you wish to add your own plumbing fixtures and control components to construct a new system. Includes: Panels, Panel and Row Hardware for basic panel assembly, connecting, and mounting.

» Deluxe Kit
Complete kit for new or existing pools. Kit includes all the components included with the Standard Kit PLUS a Plumbing Kit, a 3-Way Manual Control and a generous supply of additional components and fittings designed to enhance the system's ease of installation, performance, and user-friendliness.

» Premium Kit
Complete kit for maximum control of temperature. Kit includes all the components included with the Deluxe Kit PLUS a fully automated control package for temperature regulation.

Typical System Space Requirements
Vertical Displacement
4 x 8 Panel System - 8' 6"
4 x 10 Panel System - 10' 6"
4 x 12 Panel System - 12' 6"
Horizontal Displacement
# Panels Overall Width # Panels Overall Width
13' 3"
34' 6"
17' 6"
38' 9"
21' 9"
43' 0"
26' 0"
47' 3"
30' 3"
51' 6"

The overall width includes the minimum 3" required on all sides of each row to allow for feed and return plumbing. Different size panels may be combined; however, we suggest you call for technical assistance on these types of installations. Maximum 10 panels per row. Multiple rows required for larger systems.

Use the solar insolation map below to determine your zone and the length of the extended swimming season you may expect if your pool is heated.

Extended Swimming Season
Swimming Season
12 months
10-11 months
9 months
8 months
6 months
4 months
3 months
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