When I was at ASICSPACE earlier today, the conditions were considerably improved. The nine flexible ducts that were previously just neutral pressure outside-air intakes have now been connected to a 125 ton portable AC unit on a trailer, powered by what appeared to be a 400 amp 480V 3-phase connection. I didn't go into the cold aisles, but they appeared to be only slightly negatively pressurized relative to the hot aisles, maybe around 10 or 20% of what they had been at before. The general building interior (contiguous with the hot aisles) was strongly positively pressurized relative to the outside air, and the airflow out the open front door was very strong, maybe 50,000 to 100,000 CFM. The exhaust air from S4s felt like about 40 to 45°C, suggesting cold aisle temps around 30 to 35°C. Still high, but no longer unsafe. Most of the miners in their facility appeared to be on and hashing, although I did hear S4 beeps coming from somewhere.
ASICSPACE appears to be making a good faith effort to maintain proper operating conditions in their facility. They are putting a lot of money behind that effort. Unfortunately, they are spending it on the wrong things, like the air conditioning unit instead of a bunch of high-throughput fans. They don't need colder air, they just need more fresh air. However, the AC unit they are renting did come with a large fan inside, so there's that.
I visited ASICSPACE again on Friday, June 26th. Overall cold aisle temperature was similar to what I had seen on May 17th, probably in the upper 30s. Their cooling system had been improved a bit since then, mostly with an evaporative cooling pad in their garage door. However, their changes were only about enough to keep pace with the increasing summer temperatures. Their hot aisle was still pretty strongly positively pressurized, and any holes in their containment (or miners with their fans turned off) resulted in a significant backflow of hot air. It was about 36°C outside when I visited, but the forecast for the next day was for a high of 41-42°C (possibly the hottest it will get all summer), so I recommended that they impose rolling blackouts to keep things under control. I think Robert actually did this.
I said on May 17th that I thought their facility was no longer unsafe. When I said that, I thought that they would have made more progress by now. Temperatures in their facility is close to the border between safe and unsafe. I don't know which side of the line they are on.
I've heard they're getting 50k to 100k cfm more airflow in the next two weeks. If that materializes, that should help. Whether or not it will be enough I cannot say.