Has anybody tried these? Not cheap, but if they blow upward they should work fine. There are some by Haber that blow downward and they don't work at all if you have any speed going.
I started using a pair last summer. The fan does blow up through the upper foam. The fan doesn't move much air but it did help keep the goggles clearer. I'm going to remove some of the foam where the air exits to try and get better air flow.
I was thinking of these today,while riding. Being that we have rain most of the time while riding. I am as careful as possible,and use antifog lenses,also dual lenses. But it gets to a point where they fog,when movement stops.