Looking at your fan intake temperature it looks like your shop is a little warm to begin with. The specs call for intake air temp of 30C ad the high.
You also might be short circuiting the exhaust air to the intake. You might need to look at a better way to exhaust the heat or atleast circulate the air throughout the shop.
I do have the exhaust flow free to the main area of the shop - in fact I can feel the flow/heat across the shop (nearly 40'!)
First a question: What is the procedure for powering down? Is there a proper way to power these down in a way that keeps the fans running until they are cool?
Thanks for all the replies. It appears they are scavenging air from/over the power supplies, which are situated "inline" (front to back rather than side by side). This is because I opted for a floor space minimizing shelf design with really wide, but shallow, shelves. So I put the power supplies on their side and beside the miner to get them out of the air flow - can power supplies be on their side? Moving them out of the way dropped the temps a few degrees on the worst one but thy are still around 80-83. Otherwise they would need to be on top of, or under, the miner which just seems like a bad idea. Wish they power cables were longer. Its nearly impossible to situate the power supply exhaust out of the general area of the miner intake.
https://imgur.com/a/1xAGaThanks!
PS: I added a re-circulating fan (big shop style pedestal fan ) and it did not help.