It's a bit more complicated.
You'll also need a metal block between the Peltier and CPU and gotta make sure the Peltier is large enough for the particular cpu. You've got to insulate the cold side of the peltier, metal block, and cpu to prevent condensation. Not sure it's worth the hassle, I played with it for a bit and just decided against keeping it in my build... It could possibly fail and then become an insulator between your heatsink and CPU possibly damaging your CPU. There is a reason it's not that commonly used in CPU coolers. Fun to play with, but would not use it permanently.