@ Phoenix
Most residential AC has 2 phases/legs installed.
All you need to 'make' 220 is a doublewide breaker.
(the phases are staggered and every other breaker is on same leg)
Exception is 3 phase industrial panels where it is every third breaker.
In fact most double wide breakers are 2 single breakers screwed together with the switch levers connected.
If you have a voltmeter and long extension cord you can prove it to yourself.
Just plug in the cord and measure from cord hot to outlet hot.
(hot is small prong/hole in US outlets)
Same phase, hot 2 hot = 0 volts.
Different phase, hot 2 hot = >220 volts.
The main REASON a miner would insist on 220 is efficiency.
A >220 PSU is often 10% more efficient at making 12VDC (depends on model)
I'd guess you have 220 and don't know it.
I don't claim to know what service is installed in Volcano, HI. though.
YMMV