Cheapest Ethereum Miner Cooling System Ever Made!
I got all 5 of these fans for $14 on Amazon, http://amzn.to/2BHEpni (I think they raised the price a couple bucks). Then I used the cardboard from the Amazon box to connect them together and hang on my crypto-mining rig. It actually works! It doesn't cool quite as well as my external box fan but it's definitely better than nothing.