I attach a Virgo log entry I just made that compares chamber vibrations, acoustic environment, magnetic environment and 1-50 Hz seismic environments at Virgo and LHO.  One of the issues at Virgo is that the HVAC drives acoustic noise at the end stations that, in the 10-30 Hz band is about 10 times greater than ours.  They are concerned that the acoustic pressure fluctuations may limit A+ through Newtonian coupling. To help with attempts to reduce this noise, the log contains my rough estimates of LIGO duct air velocities and Reynolds numbers, our HVAC diagrams etc.