Useful life of an S9? Any experience or tips to extend or prolong. thanks!

[eagerbever]

Hey all, my first post on here so hi everyone!

So im a latecomer to the mining party but really enjoying it 2 weeks in.  I have 2 x S9's in my external garage in the UK.  I have been keeping the side door ajar to regulate the internal temperatures.  Am i being too paranoid about chip temps.  They are only running around mid 90's.  im also worried about the noise as i dont want to annoy my neighbors!!

I've purchased 2 that had 3 months use.  I was also wondering why they were being sold so soon.... do they not last very long??

thanks all

Eagerbever