How to Choose and Install Cooling PC Fans?

On today's blog post, I am going to show you how to determine what kind of fans are compatible with your case or cooler, and how to install them. Figuring out which fan is compatible with your case? If you have an aftermarket case, it is a snap. Check the manufacturer website, look on the side of the box, or check the manual. It will tell you which mounting points correspond to which fan sizes.

If you do not know what kind of fan you need, then it becomes a little bit more challenging. Grab a measuring tape and you can take an existing fan, which is the same as the one you are looking for and simply measure across the fan not diagonal to find out what size it is. They come in standard sizes; 80-millimeter, 92-millimeter, 120-millimetre, and 140-millimeter are the most common ones. If you do not have access to a fan, you can simply find the mounting holes in the case. Measure from the middle whole across to the middle of another whole, again not diagonally, and look for measurement that is slightly lower than the size of a standard fan. For example, a 120-millimeter fan has holes that measure from center to center about 105 millimeters.

In general, you want the air to flow from the bottom front of your case to the top back. This ensures adequate cooling for all the components inside. However, do not be embarrassed, not everyone knows how to tell which side of the fans the air comes out and in which side is an intake. On most fans, it is actually labeled. If you look closely, there is one arrow that indicates the direction that the blade is spinning and another one that indicates which way the air is coming out. Do not worry about it too much. If your fan is not labeled because all you have to do is find the pieces of plastic that are holding the middle holding the middle hub where the motor situated and in general, the fan will actually be blowing air out away from that side. If you want to use it as an exhaust fan, you just have the sticker pointed towards the outside the case and it would be blowing in that direction.

Installing a fan is simple. In most cases, you are actually just going to use four fans specific screws. Their specially threaded so they actually cut into the plastic at the fan. You just screw them in and they are attached to the case. However, there is a slight disadvantage in using screws or what is called as hard mount. That is that vibrations from the fans, particularly lower quality fans can be transferred to your case. If you do not want those vibrations, you can use rubber isolator mounts. Many high-quality fans come with them already but you can also purchase them separately. That way the spinning motor of the fan actually is in no way in direct contact with the metal the case, reducing the risk of vibrations.

Until you plug the fan into the power supply, it will not get any power, so there is a couple different ways to do that. This one right here is a 4-pin Molex. It has two wires, one for positive, and one for negative. That is it, you cannot monitor the fan, and you cannot control it because you are usually going to be plugging that directly into the power supply.

Next, we have a 3-pin fan connector. This can be plugged into the power supply using an adapter, which will be included with most high-quality fans. You can also plug it into your motherboard where you can use that third wire to sense the RPM and give you a warning if something goes wrong. You can actually adjust the fan speed using voltage control, which is the less sophisticated way.

Next, we have a 4-pin PWM fan connector. This one adds an additional pin that is dedicated to just controlling fan speed. Most new motherboards will use these babies.