i'm at the buying of parts stage for my currently-being-built-case and i was wondering whether i should just have intake fans or just exhaust fans...
my dad is pretty good at this engineering and ventilation stuff (works a lot with cars and a lot of other machinery) and he recommended having just a few intake (3 or 4) fans while having exhaust 'slits', as there are already exhaust fans on the two PSU's. he said that having a pressurised case like this should cool better than having intake and exhaust...
i don't really understand the finer points of how he said it or how the thermodynamics work so all i need is a yes, no (agreeing, disagreeing with what my dad has recommended to me) or a recommendation yourself...
I'm no expert on this, but I will tell you what I've done that works for me. I did a bit of research on this, and found that exhaust fans are necessary to help remove heat build-up quicker than just letting it go out normally through slits, etc.
So I have an exhaust fan at the top of the case, and at the top rear of the case (near the processor). The one at the top is probably overkill, but the one at the rear top, you can feel the hot air coming out.
Again, as for intake, they are necessary to bring cool air inside. I have two - one at the side to bring cool air over the video card, and one at the bottom front.
Before I started putting extra fans in, I had to leave the side off my case. Now I find that the CPU posts lower temperatures with the case on than off.
To sum up, I would definitely put in at least one exhaust fan at the top rear (or wherever is closest to where your CPU is).
Well most hardcore cooling projects on OCAU have exhaust fans, and personally dispite only have one in and one out, I think it is best to have a ratio of 2-1 or 3-1 (so 2 or 3 intakes to every exhaust)
Best cooling will come from making your case into a wind tunnel :) so 2-1,3-1 should make this happen
Also make sure you have the intakes in different positions to the exhausts
Probably a really good setup would be 2 or 3 in at the front, 1 or 2 out at the rear and even an exhaust fan in the top (above or between the PSU and 5.25" drive bays)
just make sure you get some good low speed high CFU fans (usually big ones like 120mm) to pass through lots of air without much noise and effort from the fans
Have 200 CFM coming in. And 200 CFM going out :D You must keep the cool stuff coming in and the hot stuff going out in computer cases for effective ventilation. Have intake in the bottom front and exaust in the top back and in the top. Maybe some intake in the side too. And use pretty laser cut stainless steel fan grills w00t.