I recently purchased an old dell r330 server for use as part of a homelab. I have it running in the loft but not super far from where I sleep.
I was worried about the level of noise and struggled to find much information about how loud it would be. I read comments varying from insanely noisy to barely noticeable.
To put a small bit of detail online for people who might also google this. I found it very noisy indeed on start up. The fans appear to run at full tilt before an OS is loaded.
Once my OS was installed it dropped to a very manageable level but was still too loud for me to sleep near. I discovered this was due to a single particularly noisy fan of the 4 that were installed.
I tried removing this fan but that appear to make the system unhappy (not hot) and caused the other fans to run again at high speed and too noisy.
I realised this fan was vibrating simply by touching each fan individually as they ran. Once was clearly far more violently vibrating than the others. I initially thought that I would need to replace the fan.
However I was happy (?) to discover that it was actually insanely dirty and a clear of the blades with IPA and papertowels/a small stick seems to have rebalanced the fan and returned it to the volume of all the others.
I am now happily able to sleep with it on and as a light sleeper generally this means that (at low load/temp) I would describe it as not excessively loud for home use.