Suppliers such as Papst and Verax offer especially quiet fans. According to manufacturer specifications, they operate at a barely audible 20 db(A). Although we failed to duplicate this value in the THG laboratory, very quiet operation around the 30 db(A) mark was confirmed. Papst fans feature a special ball-bearing construction and operate at a slower speed than many fans, e.g., from 900 to 1500 RPM.

Silentmaxx sells DIY kits with Papst fans for Enermax and Fortron Source power supplies. The special design of the fan blades in the Verax fan ensures less air turbulence than with standard axial fans. In the test, the Verax power supply was measured at 31 db(A), a level that is not generally disruptive to a user's hearing. An 80 mm Verax fan retails for approximately $35. The fan's diameter and height are the same as those of its forerunner.

The Verax is attached to the power supply using two crimp connections.

Swapping out the fan is simple. Unscrew the power supply, remove the old fan and disconnect the cables; mount the new fan in the same position, connect to the power supply with double-crimp connections; then screw the power supply back in place. Remember, however, that when you open the power supply housing to swap out the fan, you void the manufacturer's warranty . You must also bear in mind that this process is dangerous and you should not attempt it if you don't feel comfortable working around high voltage. Touch nothing other than the fan inside your power supply. You must also note the power supply's input requirements. Heat problems may arise with a 300-Watt power supply running at full load because of inadequate air flow produced by a replacement fan. Modifying a power supply is only advisable if it isn't constantly subject to maximum output requirements. Many power supply fans are soldered to the board of the power supply, and will require work to swap out. In many cases is might be much less work to just go with a cheaper, already silent or semi-silent solution.