[DannyBee]

i mean, even rotary screws are only like 60-70db.

I'm using scroll compressors, which are very quiet. Smaller versions are used in your HVAC system (assuming you have one).

Even basic ones are 49-50db. https://www.powerexinc.com/industrial/air/enclosed-scroll-sy... You can do better.

Most people's experience is with piston based reciprocating compressors, which are quite loud. 80+db.

Or little pancake compressors, which are the same.

Most shops move towards rotary screw because they need higher cfm than even 2 stage reciprocating can provide.