Our computer systems create heat, so it’s important to properly cool our PCs. In this video, you’ll learn about air cooling, passive cooling with heat sinks, liquid cooling, and more.
One of our biggest challenges when maintaining the operation of our computer is making sure that it remains cool. Our computers create a lot of heat, so we want to be sure we maintain a good temperature inside of our computer case. One very common way to provide this cooling is through the use of cool air. We’ll pull cool air through the front of the system. It will pass by the hot components where the air gets warmer. And eventually, we’re pushing the warm air out the back of the system.
Exactly where the air is brought from and where the air goes to will depend on your case and the style of the motherboard that you’re using. We also have to take into account the layout of the system inside, especially if there’s lots of cables or adapter cards, because that will affect the flow of the air. But fortunately, you have a lot of options for cooling your system. You can use multiple fans or different sized fans, and you may be able to move some components around within your system to improve the overall airflow.
Some adapter cards in your computer may already have a fan directly connected to the adapter card. Here’s an example of an adapter card that has a fan right on the top that is designed to cool this entire video card. Obviously, this adds a bit of bulk and size to the card itself, so you have to make sure that you have enough space inside of your computer so that fan can freely spin. This is very often seen on high-end cards, like video cards, or any other type of adapter card that has a lot of processing power and tends to get very hot.
Here’s a small example of the types of fans you could install in your system. There are many different sizes and speeds available, and it’s very common to have a fan controller built into the motherboard that can also control how much airflow is going through your system. These fans also have different noise levels. So if you find that a certain fan is very loud inside of your computer case, you may be able to replace it with a similar fan that is much quieter.
And there are some computer systems that have no fans at all. They are completely silent, and all of the cooling is done passively. This means there’s no fans or other type of cooling systems inside of this device. This is very common on systems that are very small, where you either can’t fit a fan inside of that case or adding a fan would add so much noise that you would not be able to use that system. This is very common on systems you might put next to a television to provide some type of media services.
And if you are using a system that is passively cooled, then it’s very likely the manufacturer has already put it through a number of tests to make sure that, no matter how hard you use this system, it will be able to keep up with the cooling necessary to keep that system running. If we were to take the top off of this media server or streaming device and look at the chips that are on this system, you would probably see that the passive cooling they’re using is a heat sink.
A heat sink is a specially designed piece of metal. This is usually copper or aluminum alloy, and it usually has a very specific shape that allows it to take heat from a particular component and dissipate that heat as air is passing by the heat sink. Although there is cool air helping to cool this heat sink, it can still get extremely warm to the touch. So be very careful when you’re working on a system, especially one that you’ve recently turned off, because that heat sink could be very hot.
An important characteristic of the heat sink is that it’s able to receive all of the heat from this component, like the CPU we see here, and is able to receive as much heat as possible so that it can then dissipate that heat in the cooler air. To be able to make an efficient thermal connection between the component itself and the heat sink, we need to use thermal paste. You’ll sometimes hear thermal paste referred to as “thermal grease” or “conductive grease,” but it’s all effectively the same material. This is what you’ll put in between the heat sink and that very warm component.
That will create a very good bond between those two, and it will be able to easily take the heat away from the component and dissipate that into the cooler air. It doesn’t take a lot of thermal paste to be able to make this connection. We often refer to this as being a “pea-sized amount of thermal paste” to be able to protect something like a CPU. Here’s a good example of this. This is a CPU that has just been installed, and you can see a pea-sized amount of thermal paste is being placed on the middle of the CPU. When you add the heat sink to the top of this, it will spread that out evenly throughout the CPU, making for an evenly distributed thermal connection.
There are times, though, that the thermal paste is a little bit too messy to be able to work inside of a computer system. In that case, you might want to use a thermal pad. This allows you to still maintain a good thermal connection between the component and the heat sink, but you can cut it exactly to the size you need when you’re installing it. This is obviously not going to leak or damage any other components on your motherboard, because it’s a solid pad. And although this is not as 100% effective as thermal paste, it’s still quite good and is a very good replacement for thermal paste in most situations.
If there is a drawback to the thermal pad, it’s that you have to replace it each time you would remove and replace the heat sink. If you’re using thermal paste, you can remove the heat sink, make adjustments, and put the heat sink back down again without having to replace all of that thermal paste. But if you’re using a thermal pad, you have to replace that pad each time you remove the heat sink. You can’t reuse a thermal pad once you’ve put the heat sink and fastened everything down.
Here’s a view of an installed heat sink. It looks like this one is directly on a component on the motherboard. Here’s another flavor of that same type of heat sink that’s also on the motherboard, right next to the CPU socket. You might also see cases where a heat sink is used on top of a CPU or component and then you put a fan directly on top of the heap sink.
This ensures that the heat sink will receive a direct supply of cooler air to help cool that down even more effectively. And in some cases, you can find very large heat sinks with very large fans connected to them. The large heat sinks ensure that you have a lot of surface area to be able to dissipate that heat, and the large fans allow you to move a lot of air without a lot of noise.
Instead of using air to cool your system, you might want to use liquid. This is the same type of cooling you might see in something like an automobile or a mainframe computer, where you’re using cool liquid, very often cool water, to be able to bring the temperature down of these components. This is something you might commonly see on higher-end systems that need a very effective form of cooling, especially if you’re doing some type of gaming or graphics work or maybe you’re overclocking a system and therefore creating more heat than what you might usually expect from that system.
Here’s a liquid cooler that you would use for CPU cooling. The connection to the CPU has a block and you can see there is an in and out connection on that block and the liquid would then flow to this radiator. You can’t really see the radiator in this view. It’s on the other side of this block, but there are fans on the inside that are blowing air through the radiator to cool the liquid that’s on the inside. So the installation would have the radiator receiving the cool air from the outside, and then the liquid itself would be cycled through the CPU block and back to the radiator.
Here’s a better view that shows a radiator connected to this liquid-cooled system. You would have the hot water coming from the CPU. It would be sent through the radiator. And as it’s going through the radiator, there’s usually cool air that is blowing through and cooling all of that water down. And then the cool water is brought back to the CPU, and the entire cycle starts again.