No. Actually that was a main requirement for me. I hate noises. The computer is completely silent except when doing heavy computation or maybe long video calls

No. Actually that was a main requirement for me. I hate noises. The computer is completely silent except when doing heavy computation or maybe long video calls in the browser (and then it's not that bad, though I would not notice that much because my headset blocks a lot of noises), and only if KDE's power setting is not set to power saving (though some things can feel a bit sluggish then). And the computer keeps cool. The 840 G3 was similar in this respect (that's how I discovered the Elitebook, the lab had an agreement with HP at the time), except I had to turn off the secondary HDD I chose to take when tweaking the configuration with hdparm -Y. Though the ZBook seems more focused on performance than the Elitebook, so maybe the Elitebook will not cut it if you expect similar performance. The ThinkPad actually spins its fans more easily than the HP I think, but it is also more powerful. The HP's noise when the fan do spin is also less annoying than the ThinkPad, it's a soft blow.