Haha I wanted to do the same with a few GPU's but I think the moisture will not do em good.
Is is quite an original idea tbh.
Don't worry, water only condense on an object which is colder than air, miners when running are warmer than the surroundings so there will not be condense. My net is to stop insect/flowers/snowflakes from being sucked into the intake of miners, it has large holes (2mm in diameter)
You'd be surprised how many stupid people on the forums think that water condenses on hot things. I'm glad you aren't one of the dumb ones. I ran computer equipment outside for over a year, had no problems except for heatpipes freezing in subzero temperatures.