Vertex™ Solar Powered - Solar Spa Heating Calculator

This interactive sizing calculator will help you size up a Vertex™ solar spa heating system. For a quote email This e-mail address is being protected from spambots. You need JavaScript enabled to view it with

1. the size of your spa and number of panels the calculator recommended
2. your pump lift requirements and pump kit type recommended (A, B, C or D)

Note: use Google maps to approximate your collector compass facing direction.

† These are the times of year from which the solar heating system is likely to start reaching the maximum spa bath temperatures at the end of a sunny day. The larger the system is the more likely it is to start producing an excess of energy earlier in spring through to late autumn.

System Sizing Guarantee

Sizing systems is difficult involving a lot of factors which we could get wrong. We stand by this sizing calculator, however if your heating requirements are incorrectly sized and you are not happy with the results we feel that you shouldn’t be charged the extra shipping costs for extra HDPE panels should you require them. Hence EcoOnline offers the following System Sizing Guarantee: If you purchase a heating system and you took our calculators advice on panel sizing and you aren’t happy with the system's performance, then you can purchase up to 25% more panels originally supplied by EcoOnline up to two years after your original purchase and we will ship the items free of shipping charges.