Scroll air compressors are oil free and provide breathable air (in most cases).
There are also dental/medical compressors that work as well.
The scroll ones can be used as your regular compressor if you want.
There are two ways of doing this, depending on what you want:
1. Buy a small one just for breathing air. compressorworld.com has a bunch that are 2hp or less.
https://www.compressorworld.com/oilless-scroll-air-compressors/enclosed-s
croll-compressors
This is a really expensive way to do it.
I would go with a small dental compressor if i was going to do this, which you can find in a lot of places.
Like this:
https://www.amazon.com/California-Air-Tools-10020SPC-Compressor/dp/B00WM1VPUE
(
which should work for a hood)
or this:
https://www.amazon.com/California-Air-Tools-8010SPC-Compressor/dp/B00GHPO8I2
(w
hich should work for a mask).
This one is only 40db.
There are others, just check the duty cycle.
2. Buy a scroll air compressor and use it for both breathing air and regular compression.
They are less efficient than rotary screw, but lower maintenance (and you never need oil filters anywhere). They also have no minimum duty cycle like rotary screws do.
I use a powerex SES0508
https://www.powerexinc.com/industrial/air/scroll-enclosure-systems/
It can be piped for remote air intake so you can keep it in one place and get the air from another.
Atlas copco and quincy also make some.