R730 is a dual socket server right? I would expect a fair amount of heat and power consumption from that just for storage. I’d definitely expect less heat from a shelf cause it’s only power+disks, no cpu(s). I’ve been looking for a way to separate out my storage too, with similar concerns. Maybe add power consumption too. I also want something that can fit in a shallow rack. I’d just get a synology if they weren’t so expensive.
Anyway, I found the EMC KTN-STL3 which is a 3u 15 bay disk shelf. They are dirt cheap and all over ebay. Was thinking about pairing that with a r230 or something. I think both units have a relatively low idle power usage. Don’t know about noise, everything you read is very subjective, so it’s hard to tell without just getting one. I like the r230 cause it has 2 pcie slots for hba + 10gbe nic. But if you don’t care about that or have something else already, there are lots of other options.