This exceptional water chiller can regulate fermentation temperature by pumping cold water through the jacket of the 3-in-1 (or 4-in-1), lower wort temperature post-boil when warm municipal water can't finish the job, AND chill beer in-line from keg to tap. A few of its many features include:
Please note that tap water or another chilling water source should be used for removing the large heat load post boil and this chiller used for maintaining fermentation temperature. Since this is a water chiller, it is not designed to crash cool near or below freezing temperatures. Read more about it at this link.
For conversion between 120V and 240V a $75 transformer can be purchased from this link.
BREWinfo: Water, Beer and Wort Chiller Instruction Manual
BREWinfo: Installing a portable fermenting temp controller
Video: Overview of the Water, Beer and Wort Chiller
BREWinfo: Maintaining temperature during fermentation