80mm Fan PCB Cooler for Velleman Vertex K8400

I had some problems with the pcb getting too hot. I tried the pcb cooler fan ducts that are allready designed by others, but that didn't give me the results I hoped for. Plus the fan's made a lot of noise.
So I created a mount for a 80mm fan I've bought from ebay:
http://g02.a.alicdn.com/kf/HTB1Q7eAKVXXXXaXXFXXq6xXFXXXh/10pcs-lot-DC-12V-2Pin-8CM-8015-Cooling-Cooler-Ultra-font-b-Quiet-b-font-font.jpg

You can use the original bolts from the pcb. Just add a 20 (or higher) ohm resistor in serie