Mining crypto is an excellent source of revenue if done correctly. Ive seen the use of miners in what I would consider storage rooms likely with little to no cooling. One room I was in was a steady 84 degrees while all the miners are operating in a room like that you will likely see a failure here and there soon enough. A tunnel design where ac air flows over each device and a seperate one for the power supplies would likely be the optimal choice. This being said if the miners are ran all day 24/7 this will prolonge their life due to keeping the silicone chips a constant temperature while providing optimal cooling to the units.