If you’re using an older case for your computer or think you might have temperature problems, you may wish to consider adding a “blowhole”. Simply put, a blowhole is a vent located on the top of a computer case with an outward-blowing fan attached in order to help remove hot air.

Because electronic components inside computers tend to produce a lot of heat, and because heat can damage these same components, it’s important to keep an air current flowing through your case so that the heat can be expelled. While many newer cases tend to have adequate ventilation, many cases do not. If you think you could benefit from more airflow, you can consider adding your own vents. (Plus you’ll legitimately be able to tell your friends you have a “blowhole”!)

Please note that this guide obviously can’t do everything for you. If you mess something up trying to mod your case, it’s not my fault. Don’t mess around with your case if you aren’t comfortable doing so.

Anyway, here’s a list of the essentials that you’ll need before proceeding:

• PPE (Personal protective equipment). You’ll be working with power tools and sharp stuff, so be prepared with safety glasses and work gloves.

• Duct tape to protect your case and masking tape so that you’ll have a nice writing surface.

• Fine-point permanent markers for writing on the tape

• A small carpenter’s square

• An electric drill capable of receiving a hole saw

• Drill bits for drilling the screw holes

• A hole saw, arbor and pilot bit (I purchased a 3-1/8″ hole saw with a built-in arbor and a separate pilot bit designed for the hole saw. You can alternatively use a 3″ saw, both sizes will approximately work with an 80mm case fan.)

• An 80mm fan and grille for each vent

• A clean work area, preferably somewhere you can get a little messy–metal shavings aren’t fun to clean out of carpeting.

If you haven’t already, begin planning out where exactly you want the new vent. Keeping in mind that hot air rises, you might want an exhaust fan on the top of your case, or an intake fan near the bottom. Regardless of the location, make sure that you’ll have enough clearance for the fan. Here’s an illustration I created of typical vent locations:

Once you have a general idea for the location, remove the case panel from your case and put a layer of duct tape where you want the vent. Put a layer of masking tape over the duct tape for a better writing surface. Next, use your square (or trace a case fan) to draw a square outline of the vent. Basically, you should end up with an 80mmx80mm square:

You should next make a center mark so you’ll know where to position the pilot bit once you start cutting. To do this, make a mark 40mm in on each side of the square and connect the marks:

You’re almost ready to begin cutting the hole. If you haven’t used a hole saw before, keep in mind that you’ll need to insert the pilot bit through the saw’s arbor and then tighten the arbor’s screw. Be sure the screw it tightened onto one of the flat sides of the bit, otherwise the bit will be able to spin freely. Also, you’ll want to make sure the pilot bit sticks out a bit on the cutting side of the saw, as you want the pilot bit to drill in before the hole saw starts cutting. Here’s a photo of the assembled hole saw:

Next, attach the hole saw to your drill much like you would any other bit. The pilot bit should stick far enough out the back of the hole saw so that it can be held securly by the drill.

The next step (actually drilling the hole) probably has the most potential for frustration. Basically, you need to position the pilot bit into the center marking you made earlier and slowly begin drilling. You’ll want to start off slowly so that the bit doesn’t slip. Once it pops through the case panel, the hole saw will make contact with the case panel and probably cause the drill to stutter a bit. Continue cutting, making sure the cut is even. After the cut is nearly finished, the drill will probably jump suddenly (as there is much less resistance than before). If the circular cut-out is still hanging on, you may need to stop drilling and bend the cut-out back and forth in order to remove it.

Now that the hole has been made, it’s time to drill the holes for the case fan screws. You can simply position the case fan over the hole in the orientation you like and use your marker to mark the positions for the screws. You could also measure everything a bit more precisely, but the “eye it up” method worked fine for me. It’s probably a good idea to start with a small bit for drilling the pilots, and work your way up to a larger bit to create holes that will be able to accommodate the fan’s screws. Your final bit size for standard case screws should be 5/32″. Here you can see the panel, sans tape, nearly complete:

Because the hole might come out looking a bit rough, you might want to add edging material, paint it, or grind/sand it. Since I wasn’t going for pure aesthetics, I decided not to, but the choice is yours. Either way, the final step is to screw in the fan and grille. Nearly all case fans include small arrows on them to show the direction of airflow, so if you added a vent to your top panel, be sure the arrow is pointing up to expel the hot air. If you want to draw in cool air with a lower vent, the arrow should obviously point inward. Finally, hook up the fan’s power connector to your power supply and put the panel back onto your case.

Replacing a video card’s HSF (heatsink/fan) is a pretty straight-forward process. However, the process does require a bit of patience and basic technical understanding as well as, of course, tools. You’ll also want to take precautions such as grounding yourself or using an anti-static device in order to avoid damaging the video card.

Below is the original, unmodified EVGA GeForce 6800 (Vanilla). Once the card has been pulled from the case and the power disconnected, start looking for the screws that are holding on the original HSF, and carefully remove them. There are a lot of them. Save them in case you need them again.

Part of the HSF has now been removed. You can see how wussy the stock fan and fins are:

Take caution to remove the rest of the HSF slowly and carefully. The heatsink is often glued to the memory modules, so you’ll probably need to carefully peel away the heatsink. Once this has been done, you’ll be able to see the bare components. The small black chips are the RAM, and the large chip in the center is the GPU. Before proceeding, it’s recommended that you clean out any dust and also make sure the chips are clean and ready for the new cooler. You can wipe away any leftover thermal compound from the GPU.

Here’s the front and back of the new cooler. Once you’re ready to install it, remove the plastic cover from the GPU thermal compound and peel away the tape from the RAM’s thermal compound. Avoid touching any of the thermal compound. After this, installation is really as simple as lining up the new cooler onto the video card and carefully tightening the screws that came with the new cooler.

This is the finished product. Clearly, the new HSF has a larger fan and a bigger heatsink. Next we’ll see how it actually performs.

(Methodology: For idle temperatures, the PC remained turned on but unused until temperatures stabled over a period of several minutes (assumed to be the normal idle temperatures). For gaming temperatures, each game was played with typical settings (the same settings before and after) for fifteen minutes and then temperatures were taken. All readings were provided by the tools included with nVidia’s drivers.)