Building a fanless Intel NUC... using this case with high quality thermal paste results in very low temperatures (20°C / 68°F idle).

I used following parts:

Case (Akasa Newton S6T):
US: http://amzn.to/2cz4a0S, DE: http://amzn.to/2cxr300

Thermal Paste (Cooler Master Mastergel Maker Nano):
US: http://amzn.to/2cQXSWF, DE: http://amzn.to/2cxqx23

Intel NUC Barebone:
US: http://amzn.to/2cxslIb, DE: http://amzn.to/2cxsift

Samsung 950 Pro m2 SSD:
US: http://amzn.to/2cxszz3, DE: http://amzn.to/2deTm48

16 GB RAM:
US: http://amzn.to/2d1KG6z, DE: http://amzn.to/2cz4CMJ

And Tools (iFixit):
US: http://amzn.to/2cWn6mF, DE: http://amzn.to/2dlAlwV