EL SOL SERVICES
Pool & Spa Service
SIMPLIFIED SIZING GUIDE FOR SOLAR POOL HEATERS
 A. Determine the pool surface area in Square Feet: the overall length and width of the pool.
Overall Length X Overall Width X Shape Multiplier= Pool Sq Ft
Alternate method: Pool Gallons + 7.48 + Average Depth = Pool Sq Ft
Table I
RECTANGLE1.00
KIDNEY / FREE FORM0.85
OVAL0.90
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 installation manual for precautions on installing on a flat roof.
Table 2
South Facingl.00
East or West Facing1.25
Flat1.10

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 am to 5 pm1.0
25% shade1.10
50% shade1.25
75% shade1.50
100% shade1.75

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 Shade Multiplier of 1.0

E. Determine the Sizing Factor for your Region and Pool Season desired, from the Table below. For areas other than Florida, refer to the Solar Insolation Map for the correct Sizing Factor.
9 - 10 month use11- 12 month use
North Florida
0.64
0.80
Central Florida
0.56
0.69
South Florida
0.48
0.56

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):

Square Footage (F), from above _______divided by 32 = ___ 4Ft x 8Ft Panels
or divided by 40 =___ 4Ft x 10Ft Panels
or divided by 48 =___ 4Ft x 12Ft Panels


Sizing guidelines assume use of a pool cover when night time temperatures are below 60 degrees. If a cover is not used during those conditions, the system must be oversized by 75 to I 00%. For assistance with proper sizing or design call the office.