http://ecomodder.com/forum/showthrea...tml#post184820
Highly recommended. See also
page 3 .
I ran the pump at 0.5-4% duty cycle to stay cool. If you run it at 100% duty, you're going to need some elaborate method of controlling the temperature of water in the tubes. Maybe thermostatically controlled partial recirculation? Nah, just put it on a manually operated toggle switch.