This redditor just created the most insane fanless NUC, and we love it. The massive Noctua NH-P1 CPU cooler is paired with the original gaming NUC thanks to a custom CNC-machined copper block. Thermals are amazing, the 45W i7-6770HQ barely reaches 75°C under heavy use.
"I originally purchased Noctua's passive cooler for an ITX board, however after enjoying using the Skull Canyon but hating the loud fan, I've decided to use it for the NUC instead. It's within TDP spec. There's no way the board can handle the weight of the cooler, however the cooler should definitely be able to handle the weight of the board instead.
PCBWay estimates a CNC-milled copper block at around $44. I'm guessing the bracket will be around the same price. I can 3D print everything else."
Source: reddit