Hafta say that I just replaced my fans on my P/P in Exhaust and while my setup had dust in it, it wasn't anywhere near that bad. of course I have MDPCiFlex filters on my 932. Even have one on the GPU.
But wow talk about mucked up.
Just for reference here are some before and after screenies
This is an IBT max test run this morning with the R4's p/p as intakes. Ambient temps were 20C
These are the same IBT max test run also this morning after cleaning the H50 and mounting my Yate Loon high speed fans in p/p exhausting out of the case.
Thats a 7C difference from the dirty intake setup to the cleaner exhaust setup. Both test were done at 4GHz. As you can also see when I exhaust the H50 my system and gpu temps are 4-6C cooler too. While gaming I'm seeing a 7C drop in gpu load temps by exhausting the H50. I gave the intake a shot but it def wasn't worth it im my case. Besides none of my temps are even close to the danger zone.