Every NUC I have taken apart has a fan. Such as...
https://www.youtube.com/watch?v=MwqrfIdyvGwhttp://
http://https//www.youtube.com/watch?v=EkimvAK1g0c
https://www.youtube.com/watch?v=MwqrfIdyvGwhttp://
http://https//www.youtube.com/watch?v=EkimvAK1g0c