k inteli are you talking bout the pressure drop due to temp in the closed loop because of the dry ice? i think if the loop was open to allow the coolant to drop in temp without restriction, it might be okay. Close it up when you fire it up and there should be less of a pressure change.
Is the antifreeze going in the dryice solution or the cooling loop? i guess both would be best
salt in ice water is the best way to chill a warm beer lol, doesn't the salt make the ice melt faster? how long would it cool effectively.