I don't understand why people want to make ground fog so hard. While the vortex designs work its inefficient. A abs pipe with chunks of dry ice works better, its smaller, its cheaper and there is no mess. Dry ice prices have come way down, so I just don't get it. Are people afraid of the stuff? Don't eat it and use gloves. Pretty basic. Sorry guys if i seem irritated. I just got done helping a friend with his 2 home made (vortex) chillers and I just don't get it. Yes he is afraid of dry ice. Anyway I'm sure I'll get at least one flame for this but oh well. I had to pose the question.