Just completed an install of FAFCO solar panels for my 350ft2 pool by a pool heating contractor. Although I had to install the panels (440 ft2, 10 panels) (350ft2 pool) on an East facing roof due to site considerations, I have solar heat from 0830 to 1800 in May (SW Florida area). It will be interesting to see the duration of heat I have in the winter time here in South Florida. The installers completed in approx 7 hrs with 3 installers working. One minor problem (a pinhole leak on one panel-the panel was replaced the next morning in 30 min. Believe the leak was shipping damage (e.g wood grate nicked on of the small tubes) and not an install error based on the location of the leak.
Very happy with the solar controller install (Pentair SolarTouch) which was part of the install price. The controller controls the pool temperature within 1F of set (hysteresis of the controller is + or - 1F-turning off system when pool temp is 1F higher than setting and turn on when 1F lower than setting). Since I have a Pentair VS pump, the controller also controls pump speed when solar is called for. My pump has to run 2500rpm to get proper flow and pressure up to the panels on the roof, where as I normally run the pump at 1500rpm to save electricity.. On first full day of use, the solar panels heated the pool from 84F to 91F in approx 5 hrs. The water at the pool discharges is much hotter than my heat pump-approx 4F to 5F heating delta between pump suction and solar panel discharge where-as my heat pump was 1F-2F so the solar heats the pool much quicker. On day 2, the solar raised pool temp from 88 to 92 in 3 hr on a full sun 90F day in May. Wife likes the pool warm so we can swim at night. So the only heating costs are the increased kWh since pump is running at a higher rpm when heat is called for (500 watt increase or $0.07 for each hr)
Bottom line, I got a system as promised on time and with promised results. I received 3 estimates (FAFCO, Solar Industries, and Heliocoil. All of the cost estimates were within 10% of each other (approx $9 per sq ft of panel) when they were normalized as to the amount of solar panels installed-all 3 had different heat calcs and recommendations as to amount of panel area needed for my home. There are numerous web based panel calculators-for mine I needed 410sqft per several heat calc web sites but my roof could hold 440, so installed 440 as a conservative measure since the roof faces East
The product provided by the three companies appeared to be similar in reliability and warranty based on my by internet reviews and owner reviews. The main difference between the three was the excellence of the estimator and the ratings on Angie List. I also had local knowledge of the install crew based on a neighbors house, so I went with FAFCO