The latest passive NUC case is from Impactics, and it's the biggest yet.
At 170 x 114 x 67 mm and a whopping 1380g, cooling performance should be stellar (the pure copper heat spreader alone is 220g). The D1NU1 series - designed for Intel's D33217GKE and DCP847SKE boards - starts at 99 euros.
"Combined with an Intel NUC mainboard the D1NU series allows to set up extremely efficient, fanless yet powerful computers with a volume of only 1.3 liters. Technically the D1NU is not a case but a heat sink for the built in NUC platform. Two massive aluminium heat sinks are fixed between the front and rear bezel. Lost heat is conducted via a precision milled heat spreader to these heat sinks. As no ventilation holes are required for cooling, the D1NU is suitable for all applications in which noiseless operation, dust protection and low power consumption is required on minimum space.
The heat spreader is precision milled from one solid piece of electrolytic copper (99.99% purity). Front bezel is milled from 4 mm aluminium, while the rear bezel is made of chromium steel. A special soft shield at the rear bezel minimizes electromagnetic interferences."
