Hello Frank, thank you for your great design and plans. I am building my cooler with the plug off of a Ryobi fan I got used off of Ebay. My question is would I get better cooling using a 12 volt pump? I’m afraid the 24 volt pump will cycle the water too slow, causing the ice to melt faster. I havent found an 18 volt pump anywhere or I would use that.
Thanks for your comments. Definitely, use a 24v pump. They run plenty strong on 18V and are extremely quiet. In addition, they are only pulling around 1 amp – around a quarter of what a 12V pump running on 18V pulls. Plus, a 12V pump is going to have a very short life on 18V.