Which is the best position to install a tower CPU cooler: with the fan facing the front of the case, or rotated in 90 degrees, with the fan facing the video card? Let’s find out!

It is common sense that a CPU cooler with tower heatsink must be installed with its fan pulling air from the front of the case, blowing in direction of the rear of the case. Most CPU cooler manuals instruct to install it this way.

But what if you install the heatsink with its fan facing the video, blowing air to the top of the case?

In older computer cases, there were two reasons to direct the air to the rear panel. Usually, on those cases, the power supply was at the top, and there was no opening at the upper panel. So, the only way out for the hot air was the rear panel (or through the power supply). Nowadays, most good cases have the power supply positioned at the bottom, and the top panel is meshed. That is why we are questioning the standard “blowing to the rear” position.

There is also the heatpipe issue. Some people believe that in tower coolers, the heatsink must be in vertical position, so gravity can help the fluid inside the heatpipes return to the base of the cooler, improving the cooling performance of the cooler.

In order to test those theories, we installed a typical tower cooler (SilverStone AR01) in our testbed system, in both positions, and tested the cooling performance. See Figures 1 and 2.

which is the best position to install a tower cooler?Figure 1: Traditional position (fan facing memory modules)

which is the best position to install a tower cooler?Figure 2: Fan facing the video card 

We repeated both tests with our mid-tower case at its normal position (with the motherboard in vertical position) and also with the case laid down at its right side, with the motherboard at horizontal position.

Let’s check our testing methodology on the next page.


Rafael Otto Coelho is a physicist, a PhD student, and is a college professor in Brazil.