An exhaust fan takes the air from the case and pushes it out into the surroundings. So wouldn’t that very act of removing air from the case create lower pressure in the case, causing air from the outside to get sucked in, regardless of the existence of intake fans?
In: Technology
They don’t. There are millions and millions of Dell Optiplex etc. PCs with one CPU fan and one 92mm rear exhaust, or in the case of SFF PCs, just one combined CPU/exhaust fan (+the PSU as exhaust). It’s no major problem with a ~70W TDP processor, and a handful of Watts from the other components, it’s fine. (They also use beefier fans than most enthusiast PCs).
The real reason is that PC fans produce very little pressure difference, you get a little more flow with one in, one out vs two out.
Latest Answers