Ok, effective solar heating is all about the surface area of the pool, in your case with a 26 ft diameter pool about 530 sq ft. As a rule of thumb you need something between 50-100% equivalent coverage of solar panels to your pool surface area to provide enough heat, given your rather northern location I would lean towards the 75%+ range. The most economical size of for most solar panels is the 4x12 ft size or the 2x20 ft size. 75% of 530 sq ft is 397 sq ft, lets go ahead and round that up to 400 sq ft. Or in other words 10 2x20 panels or between 8 and 9 4x12 panels. What this means is a single 2x20 Fafco Bear kit is not going to do much for a pool the size of your in your climate. Given any solar heater of this size is going to be a considerable investment, you may wish to start with a panel array that is only 50% of the size of your pool, and leave provision to add on if it does not provide enough heat for you. So lets say around 265 sq ft, or 7 2x20 panels, or 6 4x12's
There are a number of popular panel kits available in these sizes, typically the 2x20s are more commonly seen to ground level installs and the 4x12's are more common on roof top permanent installations. Price wise there are many options, the cheapest tend to be the EcoSaver panels available from solar direct or Amazon with a 5 year warranty these cost around $130-$140 per 2x20 panel assembly (actually 30 inch wide), Solar direct also sells their house private label Vortex panels with a 10 year warranty in 4x8,4x10 and 4x12 ft sizes, these are private label versions of the same Techno-Solis panels I have (you can see my installation thread here,
http://www.troublefreepool.com/threads/54481-Solar-Panel-Replacement-Update ) These panels are MUCH thicker than the roll up panels like the Fafco Bear or Eco Saver) however a 7 panel basic kit with connector hardware will cost you about $1,800 vs about $980 for 7 of the Eco-Saver panels. (twice the warranty, much simpler connection with fewer failure prone connections, twice the price....)
There are several other brands of the basic 2x20 pool kits, (sungrabber, sunheater, fafco bear, sunquest, etc.) I have yet to see one I really like.
Eco-Saver's are usually some of the cheapest, and have decent if not great instructions, biggest flaw I see is their under estimation of number of panels needed, and I am not sure what to think of their twist lock O-ring connectors.
Fafco Bear Sunsaver kits, are perhaps the best designed / built cheap panel kits out there with their build in diverter valves, etc., but the instructions have been dumbed down to the point of being nearly useless, honestly they look like they were written for a first grader.
Sungrabber I think of as similar to the Eco-Savers, but are made in the U.S., and use a more traditional hose and hose clamp connector system, often available on ebay, fairly good instruction manual with different weak points than the Eco-Saver manual. (good read if you buy them or not, same for the eco-saver manual)
Sunheater, Uses a threaded connector requiring teflon tape, which I don't like for such installations as it probably limits the number of times these can be assembled, and complicates multi panel installations.
Sunquest, seems to have a fairly good reputation, often found on ebay, also uses a threaded connector end, but can use clamp on rubber hoses between panels also. Fairly good installation manual, but not as good as some mentioned above,
Moving on up there are many good 4x12 panels made by AquaTherm (private label by Elm distribution), Fafco and Heliocoll (both tend to only sell through authorized installers) and a number of others, most are going to be priced very similar to the above mentioned Vortex/Techno Solis panels, some have different advantages than others, but there is no point going into that at this point.
Ike
