Okay, so getting cold air into the case is obviously an advantage, but I thought to myself last week, "What does it do when it gets in there?" Uncertain of precisely how the air was cycling through my case, I decided get certain and create a custom built air duct system from the top of my case to direct air through my cheap @$$ Arctic Freezer 7 Pro HSF and then out the rear.
I made a temporary three sided piece to go on a 12cm fan just to see what would happen and when the CPU dropped 8C, I went ahead and did it right. I bent this out of a single piece of aluminum using some valley metal for roofing and some pop rivets. I picked it up at Home Depot for under $10. And yes, I'm completely aware that most of you will not believe me when I say my CPU load temps went from around 64C down to 52C Real Temp Average. When I say "load temps", I am talking about playing Crysis/Assisin's Creed. That's the most load my PC will ever see anyways other than the occasional video rendering, but I don't even know if that's more intensive or not.
The downside; my motherboard temps went up 3C. I'm guessing because that 12cm fan used to blow all over and even behind the motherboard. I'm cool with this though as my motherboard cooling is completely under control.
I'll be using the duct that came with my case to attach some 3" pipe from outside, but I doubt I'll have time to do it before the end of the year. Dropping 10C or so within ambient room temperatures really surprised me. I can't wait to see what happens when I bring in the cold winter air next month! Of course, I'll likely take off the duct then anyways, or at least make a new one so the majority of the air gets into the whole case rather than just through the CPU HSF.
Update: More "How To"s on air ducts in posts #16 & 17!Edited by Paraleyes - 2/1/09 at 10:07pm