VERY impressive! Especially your worked numbers (2.5 bar, 2 mm inside-diameter feed tubing, 0.8 mm inside-diameter nozzle). I'm working in my loft, so I have nothing like the space that you have, however there are dental compressor rigs that should work well (and quietly) available for around UKP150 on ebay so, using these numbers I should be able to make something similar.

Thanks!