It’s a welch but the motor is made by emerson. It is 1/2 hp 9amp and was on their chemical duty line around 2005-2012. It is the only one in that lineup to use the 3/8" intake and exhaust. I left it running over night and it was only slightly warm to the touch. It does sound like an air compressor, not as loud as like a shop air compressor but you can hear it outside. I could probably insulate the spot I have the exhaust plumbed to a little better but if I had close neighbors I wouldn’t be able to leave it running.
[edit] been running for 28 hours continuous with no issue at all. I’m at the point where its pretty much just water left to purge off (my alcohol was weaker than I thought) and I can see where my old pump might be better (it is rated for 10 micron where this one is rated for 33 micron). Of course with the old pump I would need to change the oil after 45 mins or stop for 20 minutes every 30 minutes or so. I feel so free now I can live my life while it runs