Roof height is about 12 feet to the edge, top edge of panels would probably go up another 3 or so feet, it is a shallow pitched roof, I would estimate total pipe distance from the pump to the cold side feed point on the panel banks as about 65-70 feet. Optimum flow for these panels requires 54GPM through the panels, note all my plumbing is 1.5 inch also, base flow restriction with my current pump and clean filter is around 10 PSI with no solar (old solar came down last year when the roof was replaced). I may have this wrong, but my understanding is that 10 psi of pressure is equal to about 25 feet of head, therefore when the filter is dirty it will allow a rise to about 20 psi, or just under 50 feet of total head, the Hayward specs show the 1.5HP Super Pump show it flows 53GPM at 50 feet of head, so any loss to flow restrictions in the panels would already likely put it at below the optimal 54 GPM of flow. By comparison a quick google search shows a chart of your 1HP SuperFlo will provide nearly the same 50 something GPM at 50 ft of head, and the 1.5HP SuperFlo will provide around 70GPM. Oddly enough though my 1.5HP Super Pump greatly outperforms your pump when we reduce the head to 20 FT, providing 83 GPM vs only about 65 for the 1HP SuperFlo and about 70 for the 1.5 SuperFlo. So perhaps based on your real world experience as well as the specs I should put the SuperFlo on my short list.
Ike
