The cooling of all PC components rests on that warm air is drawn out of the housing. As a rule the power unit cannot provide a good ventilation of the housing, without its' fan running at a high number of revolutions therewith causing much noise. An additional, temperature-controlled fan like the arctic fan Pro TC solves this problem. The power unit fan can substantially lower its speed and thereby work more quietly. The temperature control allows the arctic fan Pro TC to spin just at just the right speed as the heat dissipation of the PC requires. This not only lowers noise levels, but also increases the life span of the fan.