Q5. Our hospital uses HEPA filters in its HVAC system. Should we also install the crosswind solution?

Yes, definitely.  All hospitals should consider installing this solution in a hands-free distributed configuration [view here in Part 3] in all patient rooms immediately.  It is very clear that HEPA filtering and outside air in one local hospital alone did not prevent infection in October 2020.  The fact that there were at least 7 infected in two different units at St Mary’s Hospital and an outbreak at the Montreal General Hospital supports the airborne infection paradigm:
https://montreal.ctvnews.ca/montreal-s-st-mary-s-hospital-reports-two-covid-19-outbreaks-in-two-units-1.5162703
https://montreal.ctvnews.ca/admissions-suspended-on-15th-floor-of-montreal-general-hospital-after-covid-19-outbreak-1.5174531