Home > News > How to Calculate the Amount of Solar (Thermal) Pool Heating You Need

How to Calculate the Amount of Solar (Thermal) Pool Heating You Need

How to Calculate the Amount of Solar (Thermal) Pool Heating You Need

So, you have decided you would like to install a thermal solar pool heating system, but how much solar do you need to effectively heat your pool?  


The right sized heater 

Like any heating system, it is critical that you select the right sized system for your location, heating expectations and requirements. This will ensure you, and your family get maximum enjoyment out of your backyard oasis 

As a general guide: The size of a solar pool heating system is directly proportional to the surface area of your pool. Meaning that a pool with a surface area of 32m2 will need 32mof thermal solar pool heating collector installed. 


Calculating the surface area oyour pool

Use the following calculations to determine the surface area of your pool: 

Rectangular Pool
Multiply the pools length by its width.

Example: 8 x 4 = 32m² 


Oval Pool
use length by width multiplied by 0.9

Example: 8 x 4 x 0.9 = 28.8m² (round up to 29m²)


Circular Pool
π r² or Pi (3.14) x radius² = surface area

Example: 3.14 x 3² = 28.26m² (round down to 28m²) 


Odd or irregular shape 
Take three length measurements and determine and average. Then take three width measurements and determine an average. Finally multiply your length and width averages together to determine surface area.

Average Length (6.5 + 7.5 + 6.0) / 3 = 6.66

Average width (2.5 + 3.0 + 4.0) / 3    = 3.16 

Surface area   6.66 x 3.16 = 21.04m² 

You can also use Google Earth or Nearmaps to measure the surface area of your pool. 


The Right Location

Now that the surface area of the pool has been worked out, we will need to find an appropriate roof space to install for your thermal solar pool heating system. In Australia, the preference for roof orientation is: 

  1. North 
  2. Flat roof (A roof with a pitch equal to or less than 15° is considered flat) 
  3. West 
  4. East 

A solar pool heating system that provides 100% coverage of the pools surface area is considered the minimum recommended coverage in Australia. This coverage provides a good balance between performance and cost.  

Increasing the coverage to 150% or even 200% offers significant performance gains. In particular, during the shoulder months of the season when there is less sunshine available. A larger system will achieve higher temperatures  

If the available roof space won’t allow you to install 100% solar coverage you can compromise on the amount of collector installed. Australian Standards (AS3634) suggests that a minimum collector area equal to 60% of the surface area of the pool is adequate for hot climate conditions (Australia’s northern states), while a minimum of 80% is required for cooler climates (Australia’s southern states).  There are other ways to increase performance out of smaller surface areas. Talk to your Boss installation partner or to us directly to identify how we can help. 


Still not sure where to start? No worries! Your solar installation specialist is trained in selecting the right roof and coverage for your pool, location and heating needs. 
Boss Solar has installation partners located Australia wide. Give us a call on 1300 786 489 or email [email protected] today. 

Keep up with the times

Our newsletter provides the latest product releases
  • This field is for validation purposes and should be left unchanged.
Contact Us

Contact Us Now

1300 786 489

Find out more about our solar heating range

    Name (required)

    Email (required)



    How can we help?