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VORTEX Solar Pool Heaters

System Sizing

Use Automated Sizing or follow the steps below

A. Determine the pool surface area in Square Feet:
Measure the overall length and width of the pool. Refer to Table 1 for Shape Multipliers.

Overall Length _____Ft
Overall Width _____Ft
Shape Multiplier _____
(A). _____ SqFt

(Alternate method: Pool Gallons / 7.48 / Average Depth = Pool SqFt)

Table 1

Shape Mult.
Rectangle 1.00
Kidney/Freeform 0.85
Oval 0.90
Round 0.79

B. Where will the panels be installed?
Check the orientation of the roof area with a compass, refer to Table 2 and select an Orientation Multiplier. 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. See the Solar Pool Heater Installation Manual for precautions on installing on a flat roof.

Table 2



South Facing


East or West Facing




(B). _______

C. Is the pool shaded?
Determine the percentage of shade on the entire pool during the Solar Day (9 am - 5 pm), refer to Table 3 and select a Shade Multiplier. If only a portion of the pool is shaded for part of the solar day, then a Shade Multiplier 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.

Table 3



No Shade from 9 a.m. to 5 p.m.


25% Shade


50% Shade


75% Shade


100% Shade


(C). _______

D. Does the pool have a screen enclosure?
If the pool has a screen enclosure, use a Screen Multiplier of 1.25
If the pool does not have a screen enclosure, use a Multiplier of 1.0

(D). _______

E. Determine the Sizing Factor for your Region and Pool Season desired, from the Table 4 below. For areas other than Florida, refer to the Solar Insolation Map for the correct Sizing Factor.

(E). _______

Table 4


9 - 10 Month

11 - 12 Month

North Florida



Central Florida



South Florida



F. Multiply (A) X (B) X (C) X (D) X (E) to get the required square footage of solar panels. Measure the area where the panels will be installed to determine which size panel will fit. Determine the number of panels required below (round to nearest whole number):

(F). _______

Sq. footage (F) from above: _______

div. by 32 = ___ 4Ft X 8Ft Panels
or div. by 40 = ___ 4Ft X 10Ft Panels
or div. by 48 = ___ 4Ft X 12Ft Panels

Some roof configurations may require combining several sizes of panels to achieve the total square footage. See the Solar Pool Heater
Installation Manual for details.

Sizing guidelines assume use of a pool cover when night time temperatures are below 60 degrees. If a cover is not used during these conditions, the system must be over-sized by 75 to 100%. For
assistance with proper sizing or design, please contact us.


Solar Pool Heating
PDF Format

Solar Heaters FAQ

Frequently Asked Questions

Product Downloads

Vortex Brochure
Vortex Manual
Vortex Spec Sheet
Vortex Warranty


Automated Sizing
Manual Form
Quick Sizing

Kit Contents

Standard Kit
Deluxe Kit
Premium Kit


Customer Photos
Customer Letters


Information on Above-Ground Solar Pool Heaters

Other Products

Pool Accessories
Spa Products
Solar Heater Parts

Customer Support


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