That doesnt make sense. If a heat source is a fixed output then your fluid may allow better transfer of temperatures, but it cant reduce the heat output of the rad used to cool the system. Unless your nanoparticles open wormholes in reality and send the energy to an alternate dimension?

Dude if you cut fan speeds to reduce heat emitted then you just heat your loop up. Energy does not just disappear, even if you use nanoparticles, m'kay?