That is all true--if your already own a fridge. Building a fermentation chiller is cheaper than buying a fridge (used or new) and a temp. controller. Plus, it doesnt take up the large space that a fridge does and it also doesn't consume as much energy. One of the things I love about homebrewing is that it involves so many different aspects of other hobbys to make one mega-hobby whether it be construction, chemistry, electrics, or reading. Thus, I do not have a problem spending a saturday making one of these awesome gadgets. The main questions here are whether you could use those gel-ice-paks instead of ice or a mini-dorm fridge attached to half of the chiller. A mini-dorm fridge wouldn't hold a fermenter but could contribute "icey air" if the door was taken off. Any thoughts?