ya dust is our enemy, but how do ya wanna seal ya rig? do you want to use an external radiator? i have a funny idea for you: there are cooling boxes that work with peltier elements. such a box can do about 40 watts of cooling. use such a box as water reservoir and if ya want, add a radiaror or not. this may help ya keep the temps down and if ya don't use a radiator, the only fan (if there even is one) is in the cooling box. ;D