This is a good example:
https://www.youtube.com/watch?v=xo0g2dKPAcQIt's a good way to improve efficiency but it seems risky for the boards as there's a chance of damaging it. Aside from that, it's quite a nice addition if you don't want to add more miners.
That looks risky. Best is to get fresh air in and the hot air directly out. That works for us. No fans, no aircon