My current computer has always run unusually hot no matter what steps I have taken such as: lots of fans—including four 120mms; thermal grease—both generic and Arctic Silver V; placement of the system—ie on top of a desk hutch in open air; etc.
My case came with an 80mm fan hole in the center of the side panel. I tried putting a fan there both blowing in and blowing out, but neither had much effect. I tried putting a 120mm fan just over the CPU, but again little effect. I even tried putting four 120mm fans on the side of the case with no effect (other than lots of noise). I also tried using a new PSU with a 120mm fan built in right over the CPU; again little effect. I cut a 120mm hole in the top of the case and put a fan blowing out there and that seems to have had the most effect of everything that I have tried. So now I am looking for information on fan placement and direction.
Unfortunately I am having trouble finding information on optimizing the actual placement and direction of fans in a computer case. Where can I find practical information on what fans (eg size) to put on what parts of the case, and in which direction to have them blowing. That is, not-too-technical thermodynamic/aerodynamic/fluid-dynamic tips for air-cooling a computer.
Thanks a lot.
Edit - To address some questions:
The CPU used to run between 45-60°C (I actually had to set the BIOS CPU throttling to 70°C in the summer).
I am aware of the whole airflow concept for computers (in one side, out the other). However, none of the configurations I had tried had given good results; I have even tried taking all of the panels off of the case and leaving the motherboard in free, open air without success. Which is why I asked for specific help.
I do clean out the dust and oil the fans now and then.
My case is the main problem since it has specific fan holes built in, which reduces the places that I can put fans (at least without cutting it up). For example, the rear has a metal panel that has an 80mm and a 60mm fan hole, that’s all. There is a double-80mm fan hole at the front-bottom of the metal panel of the case, but it is covered by the plastic bezel with the power and reset buttons, so it is completely blocked off.
I have already maximized the space inside the case by using rounded cables, running wires along the edges, and putting my expansion cards and drives in a configuration that leaves as much central space as possible.