So, that was an awful lot of testing and more than a few graphs, but what have we actually learnt? Well obviously we’ve found that more fans = more cooling.
This isn’t surprising or groundbreaking, but it’s good to know that you will get a direct benefit from adding an extra fan or two, which is more than can be said from adding an NPU to your case.
Beyond that we found that the placement of the fans you do have is important. It's almost more important than how many you have as we were - for example - able to achieve better cooling from three well placed fans than four poorly placed ones.
We also found that the amount of fans you’re using affects which mounts you should be using - some mounts were more useful with fewer fans, some with more.
As a result of this we’re able to fashion some simple air cooling principles which hopefully should be relevant to most builds and, as long as case design doesn’t change radically in the next few years, remain relevant for your next build too.
1. The amount of venting in your case can have a huge impact on cooling, particularly around the CPU area. If you have fan mounts here that are blocked up, unblock them.
2. Generally, all other things being equal, it’s better to get hot air out of your case than to pump cool air in, particularly when it comes to CPU cooling.
3. If you have a roof mount that’s located nearer the front of the case than the CPU cooler, leave it open. Fitting a fan here only causes problems.
4. If you have one, two or three fans in your case, the side panel intake mount is the most important. Fill this first, followed by the rear exhaust mount, followed by the roof exhaust mount.
5. Bear in mind the fact that fans have an effect on each other and use this to your advantage. For this to work though they need to be close enough to interact - a side intake works better with a rear exhaust than a front intake does for this reason.
6. With four or more fans, concentrate on traditional front to back cooling and creating one strong, continuous air flow. Fill the front intakes and the roof and rear exhausts first.
7. More fans does mean more cooling, but expect diminishing returns when going above three or four fans.
As we said, we’re confident these principles will hold true for the majority of you but, as ever, the best thing to do is experiment and see what works for you, your fans and your case. Now, if you don’t mind, we’re off for a well earned beer.