[bennelson]

Hey Tim,

Thanks for the link on that computer pump.
According to the specs, it pumps on the low end of what I would be looking for volume. Which isn't too bad, because a lower speed improves heat exchanger efficiency.

My only concern is that PVC and plastics like that pump are only rated for 140 degrees F. I don't know yet what to expect for temperatures coming out of my solar panel. On the other hand, at only $55, I could screw up once without it costing a fortune.

I think I will do a test run of the solar panel, heat exchanger, and electric water heater tank in my back yard running off my 12V stainless steel bilge pump. I'll put a thermometer on there and see what kind of temperatures we are talking about.

I do love that the computer pump is low wattage enough that I could run it off of a single 15 watt PV panel. Also, it will run on as low as 9 volts, so I think that makes it into a variable speed pump, depending on how much sunlight hits the PV panel.