Cooling case material and appearance aside. Here is the real issue. These were supposed to be professional mining machines. I have yet to see a 4U machine with an external power supply. Further, in an average cabinet, where would you put said external power supply and be able to close the door? Do we just have to eat rackspace and deal with cable management for 3cm bundles per machine? Seems like a nightmare. I have to be honest, I've got a fairly sizable order with them and at this point I'm debating asking for a refund and/or selling them. Their product is starting to look more and more like the cobbled stacks of FPGA boards on stand-offs with fans zip tied to them and USB hubs taped everywhere, not that they're doing this, but it has the design and foresight of.
-1 KnC Miner.
They are not 4RU they are 200mm, they were not designed as rack mount devices. Most data center rack shelves are up to 900mm deep, lots of space for the miner and PSU. If you can't deal with it, then you shouldn't be putting a mining rig in a data center the first place. These are not for amateurs, you probably don't even understand your insurance obligations.
Who permanently places equipment on shelves? That's amateurish. Maybe you should zip tie the PSU to the rail or stack them on stand offs.......
Also, so 5U not 4U... the point is, what uses an external power supply that is supposed to be rackmounted other than 1U appliances?