I can only offer experiential observation, based on using three different types of enclosures the past couple of years: single USB 3.0 enclosures, a Blackmagic dock enclosure, and an OWC Thunderbay 4 enclosure with the fan removed.
You might also do a search for user Babylonwaves, as he ran two OWC enclosures with the fans disconnected for a while.
As the Blackmagic dock is fan-less, and my $15 USB enclosures are what they are (though to dissipate heat, you can leave the clam shell cover off if you don’t jostle the drive), regular sample use seems to hover between upper 80 degrees to lower 90s, Fahrenheit. The real test was to see how much hotter the OWC Thunderbay ran, comparatively, under normal use, without the fan (yes, I had eleven SDDs in various use scenarios at one point).
Using a laser thermometer some months ago, the difference I noted was that the Thunderbay components generate a lot of heat after hours of use (cresting over 100 degrees), even while leaving the front grill off. As such, those SSDs temps were pushing upper 90s after hours of use. Or, 5-8 degrees warmer than the BM dock and USB enclosures when streaming samples all day. I’m guessing heat accumulated within the OWC enclosure as well from the way the SSDs are spaced in that device.
So this was enough to compel me to reattach they fan after a couple of months, just in case, though these days I only use that for tertiary backup I initiate manually every few days. As it also predated my blackmagic dock, I had to put the unit in a small metal locker with vents, padded with acoustic foam and absorbers, in attempt to minimize fan noise.
I still use four USB 3.0 enclosures, one for sample libraries in addition to the BM dock as my main streaming objection. The others are for my main project drive, and backups. But I seldom even think about the heat anymore.
