If you while reading our tutorial wanted to install an auxiliary fan in your case but didn't find any place for its installation, that shouldn’t be a problem. If the heating inside your case is really high, you can simply adapt any place for the installation of an auxiliary fan.

But where exactly can we install an auxiliary fan? That will greatly depend on which area inside the case is overheating. From our experience, we have seen that the upper part of the case tends to heat more for several reasons. First, and obviously, it is because hot air goes up. Second, it is in that area that we have, in ATX cases, the processor and its fan. And third, in that area we also have the 5 1/4" bays and those who have CD recorder or DVD unit will discover great heating of that area, since recorders produce a lot of heat while working.

Some cases have ventilation holes on their sides. Those holes are a perfect place for the installation of an auxiliary fan, especially at the upper part, where the PC heats more. As there aren’t enough holes, nor holes for the fixation of the fan, you should make them with a drill (obviously after removing the metal cover of case from your PC). In such case, the fan should be installed following the direction of the exhaustion. You should be careful to install the fan in a place where there is enough space for it, because it will “hang” inside the case and should not “hit” any internal component. That is, it should stay between the power supply and the 5 1/4" bays.

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Figure 8: The lateral ventilation holes were a perfect place for the installation of an auxiliary fan.

Another place that can be used for the installation of an auxiliary fan is the top 5 1/4" bay. Since mini-tower cases have 3 bays, and we usually only use one, we may easily make an adaptation and install a fan in that place, exhausting the hot air from the computer. That adaptation involves cutting and drilling hole on the plastic covers of the 5 1/4" bays. Indeed, some manufacturers are already selling fans ready to be fit into those bays.

Figure 9: Exhaustion system for the 5 1/4" bay.

In other words, you can install an auxiliary fan where you think the computer is heating too much, making the necessary adaptations in your case. Just one more thing to what we have been talking about the direction of the air: the auxiliary fans installed in the upper part of the case should be installed following the direction of the exhaustion (air flowing from inside the computer to outside), while auxiliary fans installed in the lower part of the case should follow the direction of the ventilation (air flowing from outside to inside). That will make the air flow inside the case follow its proper path.

Another detail that we have not mentioned is that there are smaller fans and some cases have space for the installation of that fan type, as it can be seen on Figure 10, where the case has space for the installation of a 50-mm auxiliary fan (the standard size of the auxiliary fans we have been talking about until now is 80 mm). Many times those places go unnoticed, due to their reduced size. As the space is located at the back of the case, the fan should be installed following the exhaustion direction, forcing the hot air inside the case to leave it.

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Figure 10: Place for the installation of a 50-mm auxiliary fan.