Hello Drok,
I have ordered, and am using, and will probably be ordering more of, your 0-24v 480w power supplies. Unfortunately, they have 2 defects: The fans and the potentiometer. I have replaced these on all units, sometimes within days of purchase. The fans are way too loud and the potentiometers are sometimes the wrong size and/or wattage. They blow very quickly. So, I have replaced them with 1/2 watt potentiometers. The fans have been replaced with same size and output, but quieter fans.
May I recommend that you put stronger potentiometers and quieter fans in your power supplies? Or, you might lower the fan speed. Lastly, I have tested the PS units under load (with new fans) and the max inner temperature remains between 40-50 degrees celcius. Do you have a maximum rating on inner temperature?
Best,
Rick