Perhaps you could add salt to your installation to counter te humidity, this is what I used to do to store oven-dried concrete specimens during my master's project.
There are frequent down-times, I have a mining rig consisting of 2x6 1070 GTX and I am lucky if I get 7 days in a row up-time.
Can't your work provide you a storage closet?
Thx, I also thought of using salt to counter humidity. From what I have read, it should be quite effective. And yeah I know I won't be able to have a 100% up-time. Maybe 90%-95% if I'm lucky.
I'm sure I can find some space to run the rig indoor. Either at work, a friend's place or somewhere else. I'm not quite giving up the outdoor project just yet, as it has some interesting challenges.
Will keep you posted.