By the way - forgot to thank you for that link. My shop is completely open and the warm air mixes fairly completely. So there is no cooler area to move air to, but that ventilation fan you posted a link to has my gears turning - I may be able to rig something up yet.
Thanks again
Quick update. I moved the miners to a shelving unit directly in front of a window. And I situated the miners so their exhausts go straight out the window. This completely solved my problem. My intake and chip temperatures improved dramatically. By the way, my windows have screens so shouldnt have any issues with bugs, etc. I cant wait for winter so that my miners heat my shop and I can save money on heating :-)
[later edit] By the way, I determined the real root cause was this: Even though the shop is large(40'x30'), the miners were in the corner and blowing exhaust out along the 40' wall. The exhaust then however continued around the shop, creating a a swirl that circled the entire shop and the miners were then swallowing their own only slightly cooled exhaust after it made a round trip. Apparently opening all the windows disrupted it only a bit unless it was a windy day. In fact, a recent very windy day saw substantial improvements in the intake temps and that is when I had my "ah-ha!" moment.