Ok, got myself a dual digital thermometer device.
There are no fans connected right now. Ambient room temp. is around 22.5 degrees Celsius - not a hot day to our standards.
With the sensor attached directly to the CPU HS and the monitored machine more or less freewheeling with MemTest running, the temperature has gone up already to 42.9 degrees, and still rising. One side panel is open. Hard drive is idle too.
Not sure though how much heat it can take. I think I'm about to switch it off soon and I'll just have to wait a bit until the PAPST fans arive.
Oh - tried this
yesterday on one of the disassembled ADDA's.
Makes a difference of course, although not satisfactory, but my biggest surprise was when I removed the fingerguard. Now *that* was an improvement! Those little thingies are a pain. I'll leave the top one w/o guard, because it's hard for anything to hit the fan in that position.
Fetched a chromed one from a donor machine and you win a few dB. Another concern is vibration. As soon as I bring the fan in position it becomes a turbine. I wonder in what matter silicone based mounting rings and ducts might help?