Having both fans set perpendicular might be recirculating just the warmer air from the top of the keezer. Have you considered pointing the cave's exhaust fan down and at an angle away from the intake (or use a deflector) to stir up the colder air from the bottom?
I apologize for reviving this twice dead thread, but to save anyone in the future the headache I went through, here is what should be a permanent link to the plans for this crate...
