R.A.L.F. October 2007

Repetitious Assembly of Little Fans. Summer's here and what better use for a few old case fans than to cool off the room? Same theory of PC cooling should carry over to human cooling - next project might be a liquid cooled task chair.

First find several fans and mechanically joining them. These are attached to one another with cable ties.
Old case fans

Next we need a suitable power supply. What did this thing run at one time? States 16VDC.
Wall wart power supply

No load, the power cube gives 19.67v
19 volts

Tie all the red fan wires and power supply's + lead together and all the black wires together and the power supply's - lead. Get the polarity right, the fans won't spin with reverse polarity. With load, it drops to 16.83v
16 volts

Dress the wiring. We don't want any fans chopping off their own power supply lines
Ralf wiring

Put R.A.L.F. in a northern facing window, apply power and there you have it - a cooler computer room.
Ralf in action

Download an mpeg clip of R.A.L.F. in action.

Footnote 2009. R.A.L.F. still functions. Great reuse of scrap parts. Just don't get a finger in the blades.