20 min for 20oC to 0oC, for one gallon.
Given: One gallon of water takes approximatley 200 seconds to heat one degree kelvin/celsius with a 80W heat source
(as stated by Dix Dogfight here:
http://forums.procooling.com/vbb/sho...&threadid=3501 )
or 3.33 min per degC
or 66.7 min for 20degC
Your chiller is about 3.3 times more powerfull, aka 264 Watts.
Yeah, that'll cool a CPU.
How big is it?