which would be perfect because a thermoelectric generator uses the differences in temperature. So if the space between the motherboards and the heatsink/thermoelectric generator can't be reached by the fan, but the other side of the heatsink/thermoelectric generator can be reached by the fan and cooled, then the electrical output will be greater.

Anyway, 2 questions, where did you get your fan and if you're mining using a Erupter, do you even really need a fast computer or can you just use a cheap, semi-crappy desktop?