I can recommend going for fanless cases, like the one from Akasa, Streacom or Impactics. In my case I am using several Akasa Max MT and Impactics D2NU1 (D2NU2)

I can recommend going for fanless cases, like the one from Akasa, Streacom or Impactics. In my case I am using several Akasa Max MT and Impactics D2NU1 (D2NU2) cases and they are perfect for my all-silent home lab. Sadly the turemetal cases are not available anymore :(