Background. 208V outlet was put in when I was doing the children's clothing years ago for the silkscreen equipment and clothes dryer. Getting the 230V Dewalt compressor I got this transformer:
ACME T181052 Acme, Buck Boost Transformer, 12/24V 750va
Because I needed the dryer to work (cleaning polishing fleece blankets), I mounted the transformer on the wall and added a dryer extension cord and an outlet to it. For 5 years the compressor is plugged into the transformer outlet. Then the the transformer and dryer were alternately plugged into the 208V wall outlet.
Just did some testing.
Wall outlet is putting out 212V
Transformer outlet is putting out 96V. Enough for the dryer to work off it (just as a test) but not enough for the compressor. I can take the cover off the transformer end of the day to inspect.
Environment is essentially office space. Clean, dry.