You can make those rackmounted servers as loud or as quiet as you like. For home, optimize quiet (and low power consumption).
Even though my server rack is in the garage I try to keep it quiet. A couple of them are fanless Atom-based and others have fans but they are built to be quiet. If you need hardware that generates a lot of heat, go with 4U for large fans that spin slow, thus low noise.
The "wow, leafblowers sure are quiet" happens when you stuff a lot of heat generation into a 1U chassis that then requires lots of tiny fans running at full speed. Those you don't want at home! But it is easy to avoid. Data centers do this to maximize density, but that's unlikely to matter at home.
>Atom-based
Not exacty enterprise grade servers then?
Supermicro sells Atom-based SKUs with enterprise features like a BMC+IPMI, 10Gb SFP+ ports, ECC memory, SFF-8087 ports, chassis intrusion detection, etc.
And do you need a full-on enterprise-grade server? Given the choice between a 1U server whose fans even at minimal utilisation can still be heard three doors away and something with a low-power/laptop-grade CPU that does the same job silently and with little power use, I'll take the latter.