How to Cut a Fan Hole


Cutting a blowhole in your case is probably one of the easiest case mods and one of the most effective for cooling down the inside of your case along with the CPU. You can put the hole anywhere in the case that it will fit. If you are an overclocker, especially with AMD you know that those CPUs can get hot. If you have no air flowing through your case the hot air will build up within it and be pushed back over the CPU thus making it hotter. Adding fans to your case will give it the airflow it needs.

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What you will need:

  • Fan
  • Fan Grill
  • Masking Tape
  • Pencil
  • Measuring Tape
  • Dremel or other cutting device
  • Drill & bit

I had an old AT case laying around so I decided to use that sense no mods have been done to it yet. Don’t worry about the fact that its a pile of junk I am just using it for demonstrative purposes. As you can see this case has little to no cooling.

There is no reason to go out and buy those blowhole template things, all you need is a fan grill which is the same size as the fan you are going to be using. You will need to decide where you are going to put your hole and make sure that it will work there. For blowholes you need to make sure that you put it where it will not touch the power supply and to make sure a drive will still fit in the bay.

I didn’t have anything to put in there without taking it from another computer so I just guessed however you will really want to make sure. I put it right next to the power supply as far back as possible so that a drive would have adequate room to be installed later.

After you have decided where you are going to put it you will need your grill, this will be your template. Put the grill where you where you want your hole to be and trace around the outside of it also do the holes for the screws on the inside. If you want to make it look professional, use a measuring tape to center it.

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You will want to use masking tape where you are going to cut the hole, this will ensure if you make a mistake that you will not mess up your case. I did not have any masking tape and didn’t feel like going out and buying any so I will not be using any.

I did find duct tape which I used just to show what I am talking about. I would definitely advise against duct tape. Use masking tape or nothing. I will show later why you will want to use the tape. Below is a picture with the tape and without.

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Now that you have your outline traced you are ready to cut. Be sure like always to use safety gear, goggles and a mask are suggested. Don’t hold me responsible if you don’t, trust me you will want both. You will also need your Dremel with a cutoff wheel.

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The best way I have found to cut anytime with your case is to go around it a few times rather than trying to just battle though it all at once. If you go slower and a few times around you will use less cutoff wheels. Trace around the hole with the Dremel trying to stay within the line. Also if you outline your cut first it creates a groove which will guide your cut.

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After you go around say 2 times you will want to start putting more pressure on, so that you slowly cut through the case. Do it in “bites” don’t try and ride the Dremel all the way around in 1 cut. Cut into it slowly and just keep cutting around until you are through. As you can see its not too pretty to look at, its jagged and as you can see I made a mistake, I wasn’t paying attention and the Dremel got away from me and ground the paint off the case. If I had used masking tape while doing this the case would not have been scratched because the tape would have protected it.

Go ahead and attach a grinding bit to your Dremel or you can always use a rounded file. Use it to clean up the sharp jagged edge so that it is smooth and nice looking. Be careful the edge is really sharp and will cut you. When you are done grinding or filing it should be smooth enough to run your finger across it.

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Now you will need to drill the holes for the screws which will hold the fan to the case by the grill. You can put the case against the wall so that the hole is facing you and use a level if you like to get the holes level or you can just eyeball it. Get a drill and a bit that fits through the hole of the fan grill and drill out all 4 holes.

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Now all you need to do it attach your fan to the new hole and put the cover back on your case. Put the fan under the hole so that you have it either pulling air out of the case or pushing it in and put the grill on top of the case, align the screw holes of the grill, case, and fan and screw the screws into the fan which will be held on by the grill.

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Now that you have successfully added a blowhole to your computer go crazy put holes all over your case. As you can see because I did not use masking tape the results were not as good looking as they would have been if I had used tape which is why I really recommend using it. Some other good places for holes on your case are in the front bottom as an intake, back top right behind the HSF for an exhaust, and on the side of your case where they can blow directly onto your CPU and video card.

Brandon Turnbull is a technology enthusiast living in southern California. He has written numerous articles and tutorials about PC overclocking and modification.