My computer case has a fan mounted on the inside very near the side of the case. It blows onto the CPU. However, when the side is on the case, the back of the fan is nearly pressed up against the wall, allowing for very little intake to the fan. To solve the problem, I punched a hole in the side and mounted a grill and filter. Now the fan can suck all the air it wants from outside of the case. I was very happy with the results – more happy than I thought I’d be. It looks like it belongs.
You can see some professionally filmed and edited footage of the case with hole here. In case you can’t tell, I used a complex arrangement of magnets and yarn to get the front of the case to pop off as it does. Now tell me what you think.