in the US what kinda plug outlet would you need for 220V?
I was actually researching the same thing recently after seeing 80 PLUS having better efficiency on 230V
An electric dryer / stove socket would likely be NEMA 14 in newer homes, where there are two 120V lines with 180 degree phase difference, creating 240V. Older homes would use NEMA 10.
I found these adapters which are meant for electric vehicle charging. Then you could use a rackmount cable to connect to the PSU.
What's been stopping me is that the 2% gain in efficiency is only worth it if you are drawing a lot of power, having to put the machine in a specific room or pay an electrician to wire another socket to the room you want.
You would be fine with a NEMA 6-15P. (Rated up to 15A at 250V, far more than a single Avalon will pull)
Converting a 120v circuit to 240v yourself is actually pretty easy, you just need to make sure you account for everything on the circuit. Most residential circuits have a combination of receptacles and lights connected; ideally you find a circuit with no lighting and as few receptacles as possible, cut the power at the load center, replace all the receptacles with 6-15R or 6-20R depending on wire gauge, then replace the circuit breaker with a double pole breaker and connect both conductors to the breaker and you're good to go. If you want to comply with the National Electrical Code then I believe you need to put a piece of black or red electrical tape on the white (previously) neutral wire to indicate it being a hot.
*disclaimer: I'm not responsible if you electrocute yourself.
I don't think the difference in efficiency between running a PSU at 120 vs 240 really warrants doing this unless you're running a lot of units though. (and in that case you may need to use 240v or run a new circuit to avoid overloading the existing circuit @ 120v)
