I dunno. I think I might have to give these a thumbs down.
I have a rather large self installed setup on a steep 45 degree pitch garage roof. There are 8 2x20 panels and they are strapped down in 3 places according to the instructions. The panels are sloped from one end to the other according to what is recommended for drain down. So where are we at?
1. The panels look ugly after first being installed. They like to ripple and not lie flat. A vertical panel installation wouldn't have this problem. Even after being installed a while they still aren't really great. When it gets real hot they ripple up and only flatten out when it's cool at night.
2. The panels full of water are too much stress against the 3 hangers. This causes the bottom 5-6 rows of tubes on each panel to deform and seal shut. No water flows through these tubes but they still fill up with water. Come winter time, these tubes won't be drained out and many of these rows have leaks for me, especially near these stress points.
3. The panels installed according to instructions simply don't drain down. I have to get on the roof and blow them out. The year before I figured out you can blow out 4 panels pretty well with a shop vac. Last year I decided to stay on the ground and attempt to blow out all 8 panels at once. Now that I just started the pool up it looks like that decision has ruined every panel. Numerous leaks everywhere.
The first year I had one panel leak right after installation. Fafco sent me a new panel. I then had another panel leak and they just sent me a patch kit with the little rubber plugs. They have a 10 year warranty, so I am considering sending all of the panels back.
Sorry but I'm pretty unhappy and I don't know if I'll try to save money on this stuff again. a 8 x 4x8 setup for only 256 sq ft would cost me over $2500 whereas this cost me just over $1000. That's a lot of $$ but I don't know if it's worth the frustration. I really thought I was getting nice easy to work with rubberized panels that would lay flat and drain down well but that isn't going to happen unless the panels are mounted by the strong headers and the tubes face vertically imho.