Our plan C is making a box that we can put on the patio and circulate outside air. There are space restrictions and we are dealing with 100F + air to cool cards. I was messing with some thermodynamic formulas to figure out how fast the rigs would heat up different volumes of air. So far my rough estimates are 4.88 seconds to heat 27ft^3 from 73F to 100F with 3,000 watts. So we would need to exchange the air faster than that. I figured 3 200mm 129CFM fans should do the trick.