How To Install Case Fans In A PC

Our PC generates a lot of heat while we use it. Manufacturers provide in-built heat sinks and mandatory CPU fans to lower the CPU temperature and take away some heat from the PC.

But it is not enough at all. You need additional casing fans to pull cool air inside the PC and take the hot air out from it. Nowadays, due to higher system capacity and its usage, PC fans are needed even more. Modern PC cases provide a number of housings to place such fans. You can install the fans in these positions to get the optimum cooling effect.

It is not that difficult to install PC fans. You just have to find the right type of fan, identify the inlet and exhaust sides and screw it to the given position in the casing.

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Install Fans on PC

If you have not already bought the PC fans, you should first scrutinize what kind of fans you want. You may get a Pulse Width Modulation (PWM) fan that provides you with the ability to change the fan speed or the normal DC fans without this feature. Even if you already have one, you can opt to change the fan to entertain this function.

Furthermore, you may want to look at the number of fan header pins on your motherboard. A three-pin header will not provide you with the function of changing fan speed. So, why waste extra money to buy a PWM fan if you cannot even control its speed?

Now that you have the right kind of fans, let’s move on to the steps to install them into your system.

Identify the Number of Fans to be Used

You should look at how many fans your system can house inside. Almost all PCs have a rear area to set an exhaust fan. Some have places for two exhausts at the back. Also, some PC cases have a place to keep exhaust fans at the side as well. Similarly, you may have an area in the top or front panel to place inlet fans.

But it is not necessary to use fans to cover all the available housing. In fact, using four or five fans improves the cooling effect by only a small amount and only serves the purpose of aesthetics.

So, you should base the number of fans in terms of the cooling requirement. This depends on the purpose you use your computer for.

A normal working PC can be cooled by using a single exhaust fan at the back. But a gaming PC is recommended to have atleast two fans, one inlet in the front and one exhaust at the back.

You can arrange more inlet fans than exhaust to create positive air pressure to improve the cooling effect. This causes the higher air pressure inside the PC to bring out the dust as well.

There is also another setup where you can use more exhaust fans than inlets to create a vacuum inside the PC. This forces every small pore in the PC to suck more air inside, cooling them properly, but it tends to absorb and accumulate more dust.

You can ignore all these and use an equal number of inlet and exhaust fans as well.

Nevertheless, the general idea is to use one set of fans to suck cool air from the room and another set to remove the hot air from the PC. Thus, choose the best combination for your PC.

Find the Optimum Position For Fan Placement

It is not that once air enters the system, the PC will cool down. The air also needs to come out of it along with the heat in order to lower the PC temperature properly. But if the placement of the fans is not done optimally, then the hot air may get trapped inside, lowering the cooling effect or heating the PC even more.

So, you should find the optimum position to place the fans. If you are using a single inlet fan and have multiple fan housings at the front, you can place it directly in the middle so that the air blows directly to the motherboard. Similarly, you can simply place the exhaust fan at the back for this setup.

But for multiple fans set up, you should place them to create a wind tunnel effect such that the flow of air current occurs continuously throughout the PC.

Furthermore, you should also see if the fan cable is long enough to get to the motherboard from the placement point. If not, either you may have to change the position or get an extension cable.

Remove the Casing Panels

Now that you have finalized the number and position of the fans, let’s start removing the casing panels.

Bring out the casing to an open area.
Similarly, unscrew the nuts of the side panel and slide the panel out. You can place the fans at the top, side, and back front from the inside of the PC.
If the case has fan housings at the front, then you should open the front panel. To do that,

Place one of your hands on the bottom part of the front panel. Most of the casings have a hole in the bottom.
Put another hand at the top of the panel to support it.
Pull the panel out from the bottom. Be careful with the internal motherboard cables, as some of them may be attached to the panel.
Some front panels may require pulling from the sides as well. Look at what is suitable for your PC.

Identify the Inlet and Exhaust Side of the Fan

Before mounting the fans, you should first determine the side that takes the air in and the side that blows the air out. This is important in order to place the inlet and exhaust side of the fan at the proper orientation. You can identify the sides or the direction of the fan rotation by following ways.

Most fans consist of an arrow that denotes the flow of air. If it is marked inside, then that side of the fan lets the air in, and another side is the exhaust.
If there is no arrow, find the sticker denoting the name of the brand. This side usually is the front part of the fan and is the inlet side. The other side consists of the sticker with the specs of the fan and is usually the exhaust.
Another technical way to find the inlet and exhaust side is to see the curvature of the blades. If the curvature goes anti-clockwise from the side you are facing, then it is the inlet side, and vice-versa.
If you are still confused, you can connect the fan in any orientation and let it spin. Now place a small piece of paper at the front of one side. If the fan blows the paper away, then it is the exhaust side, and the other is the inlet. Then, change the orientation accordingly.

Mount the Fans

The process of mounting the fan is quite easy. However, the main thing you need to consider is the placement of the inlet and exhaust side of the fan.

For the housing where you want to place the inlet fan, for instance, the front panel, you should keep the inlet side facing outward and the exhaust side facing inwards. This allows the fan to take air from the surroundings and blow it inside the PC.

Similarly, in the position where you want the exhaust, you should place the inlet side facing inwards and the exhaust part facing outwards. Thus, the fan takes all the hot air and blows it outside of the PC.

Now, let’s move on to mounting the fans in their proper position and orientation.

Clean the dust in the fan, if any, and bring the fan to the housing area in its proper orientation.
Take the wire out of the way of the blades carefully.
Align the screw hole on the case and the fan.
Put the screw in and tighten it with the screwdriver.
Similarly, place another screw at the diagonally opposite corner and tighten it as well.
Now, tighten the remaining screws.

Do this for all the fans you are trying to install. Again, make sure the inlet and exhaust sides are oriented properly.

Connect the Cables to the Motherboard

To power up the fans, the cables need to be connected to their proper header in the motherboard. There are different fan headers, namely the SYS_FAN, CHA_FAN, CPU_FAN, and AIO_PUMP. These case fans should be connected to SYS_FAN or CHA_FAN but not to the CPU_FAN and AIO_PUMP, which are reserved for the CPU fan and AIO Pump.

Find the headers in the motherboard with the above-mentioned names. If you are not able to find it on the board, look at the motherboard manual or diagram to identify them.
Bring the cable up to the header by properly arranging the extra wire with clips or any wire-management tool.
Insert the connector into the header. You can generally find a rail-like extrusion in the connector that makes the path to insert it into the header easily.
You can also use the four-pin connector for a three-pin header and vice-versa. The functionality will vary, as mentioned earlier.
If the fan has an RGB cable, then find a header named ADD_HEADER, JRAINBOW or LED in the motherboard and insert it there.

If the cable is not long enough, or there are not enough headers in the motherboard, then please follow the instructions below.

If the cables do not reach any headers on the motherboard, obtain an extension cable and insert one end of it into the connector and another into the header on the board.
You can also insert the connector directly into the MOLEX cable coming out of the PSU.
If the headers are not enough to fit all the fan connectors, then use a splitter cable. But using more than two fans in the single header using a splitter can overload the fan port and damage it.
Similarly, you can also obtain an adapter or hub with multiple fan headers. Connect the hub to the MOLEX connector coming out of the PSU and insert the fan connectors in it accordingly.

The only limitation of connecting fans directly to PSU is that you cannot control the fan speed, and it always runs at full speed. So, you can connect the PWM fans directly to the four-pin header in the motherboard and other fans through the hub or PSU.