See this post for a recent discussion of a very fast chiller Jaded Hydra. I have no experience with it myself. Stirring the wort while chilling makes a big difference. If your cooling water running through the chiller is too warm, as it can be in summer, then you can use a 2nd wort chiller to cool it. Put the first chiller in a bucket full of ice water and the 2nd in the wort.
