Shinyknight,
You're using a compressor - which is heating up to relatively high temps - which is also heating oil,
so, you'll tend to notice an oil / petrol-like smell.. Add in a bit of Chinesium machine/tool smell, and yeah - Pew..
I use Royal Purple fully synthetic compressor lubrication in mine, so, I doubt that I'm noticing as much of a scent as you are..
Taking that long to vent the chem-smell does sound a bit excessive to me though.. Are you just running regular motor oil?
Even the 'so-called recommended' #46 hydraulic oil Is Not really recommended.. I'm thinking that's probably part of your problem..
The Royal Purple and even Amsoil brand compressor lubes works the absolute best, and you won't be overwhelmed with any weird smells..
I've used my comp to fill an 88 cf carbon fiber SCBA tank from zero psi to about 4,700 psi, and still use it to top that same tank off
I only smell the hot smell / chem smell until' everything cools down, and then everything is back to normal..
I have lived in 2 different apartments, and I've used my Yong Heng in both of them..
Apt 1 had a room no bigger than a 12' x 12' and I ran the comp in there.
Apt 2 - where I'm at now, the room is close to the same if not smaller..
Run for no longer than 10-15 minutes at a time, and keep the compressor as cool as possible..
And before I forget link to RP from Napa:
https://www.napaonline.com/en/p/RNJ01513 Sam -