The enclosure is an Athena Power BP-SAC2131B 3.5” HDD Hot-Swap Backplane Module. This is a a 3-bay hot swap backplane intended to go into two 5.25” bays of a server. This is not a trayless backplane, the hard disks must be mounted using four included screws.
This is a 3-bay case, but I only need the top two bays for hard drives. In the bottom bay I will put the computer that runs the NAS. Something like a Pico-ITX or 3.5” SBC computer will fit within the footprint of a hard dive.
The main problem with using an internal enclosure as a case is that all the SATA connections ago out the back of the case, not internal for connections to a computer.
Luckily there is a slot on the back of the case. Using something like these very thin blue SATA cables, I can connect an internal computer to the back of the case.
Silence the fan
The enclosure’s included fan is very loud. Which is understandable considering it was intended for server environments.
I considered replacing it with a quiet computer fan but it uses a nonstandard fan size, it is thinner than a standard 80mm fan. Also, while it’s just a voltage controlled fan, it doesn’t use the standard 3-pin CPU fan connector.
Disconnecting the fan is difficult because a buzzer alarm sounds when the enclosure detects 0 RPM on the fan. The alarm may be silenced by pressing the “reset” button, but it will sound each time the NAS is power cycled. However, it appears two pins on the back of the case are connected to the front reset button, so you can simply put a jumper across them to permanently silence the buzzer.
The bigger problem is that HDDs actually get hot. Not much, but they do require some cooling. With the fan disconnected the disks quickly got up to 45°C and kept climbing towards 50°C.
Read more: DIY NAS / Router in 3-bay hot swap enclosure