Thursday, May 23, 2013

Efficient Air Cooling for your PC

Although with high end PCs liquid cooling is becoming more and more prevalent, I just never was able to get over the idea that my really expensive electrical components would be right next to a hose full of liquid that could leak or burst at any moment, ruining my expensive components. Add to this the trials that come with living in a humid climate (forms condensation outside the tubes) and you have yourself a good reason to consider air cooling alternatives.

Thermal Dynamics
To really get a good air cooling system you’ll need to know some of the basics of thermal dynamics. Simple rules like “heat rises” are important, but not as much as how heat moves from one type of material to the other. Obviously your metal materials like copper and aluminum are great heat conductors. Air absorbs heat pretty well, but the molecules are so spread out that the effect is not as prominent. This means that in order to maximize dissipation of heat, you want to move a lot of air over the hot surfaces and of course the more surface area you can create, the better off you are for this (this is the principle behind heat sinks). Heat is also absorbed by liquids better than air because of the higher density of molecules. Now this would seem like an argument for liquid cooling, but you can get the best of both worlds by using heat-pipe solutions for your hottest components.

Obviously you’re going to want to use a case that’s mostly if not all aluminum or some other type of highly conductive metal to help better radiate ambient heat in the case. Knowing that heat rises you’ll also want to make sure your case has a place for a fan at the top (or if it doesn’t, you can create one with a hole cutter and a drill). This will give ambient heat a convenient escape if it’s not in the main flow pattern. To create an effective airflow you’ll want the biggest fans you can mount to maximize the volume of air being pumped through the system. Use power efficient fans when possible as these will generate less heat from operating and thus make them more effective at cooling the rest of the system, but don’t sacrifice speed as the faster the fan spins, the more air it can get into the system. You’ll also want to include dust filters of some sort to prevent dust from clogging up your systems heat dissipation components as dust will absorb and hold heat preventing it from being effectively removed from the system.

Airflow pattern
The objective when setting up your system is to create a vacuum inside the case that will suck in fresh cool air. This is accomplished by setting up more exhaust fans than intake fans. You also want to make sure the air is flowing through open space (so cable management is a must) and is effectively passing over your hottest components (typically CPU and GPU) before leaving the system. With a typical case a good way to do this is to set up your intake fan at the front of the case and your exhaust fans at the back, on the top, and on the side. You also want to make sure your CPU heat sink is facing so that the air will flow in between the fins (have the fins running from front to back rather than up and down) so that it will pass over all the surface area rather than have it run into the broad side of a single fin. Once the air passes through the heat sink it gets channeled out the side, back, and top exhaust fan areas. The one problem with air cooling in hot environments is that the air inside the case can never get any cooler than the air outside the case. As such if you really want to keep your PC cool even under a heavy load, you might want to consider keeping it in a cool environment or even attaching some kind of air conditioner unit to the front intake in order to maximize how much heat the air can absorb and carry out of the system.

If you have a high-end PC that you want to keep cool and you’re nervous about liquid cooling as I am, you may wish to consider an air cooling solution for the PCs in your N3rd C0rn3r.