82°C-95°C I think just fine for Antminer devices.. Don't be afraid like that,this devices can handling with max. 125 °C.so I wrote to Bitmain and they said me this.
80c above is fine, but not so good and if you can decrease the temps below 80°C your miner can live longer than the higher temps.
I think the miner s9 will automatically shut down when overheating or the temps reach 115°C if you force the miner to the higher setup your hashboards will die fast. So, keep the temps lower than 80°C if you want the miner to live long.