I just saw an interview with one of the people transferred from the Grand Chancellor for a second 14 day quarantine when he and his wife only had 1 hr to go of their original quarantine.
However as part of that story they showed the Grand Chancellor and many sitting and standing on their balconies with the sliding doors all open and the trees in the street being blown about. People in adjoining rooms , including rooms above or below another room are to be seen maskless within metres of one another which is hardly prudent if an of them are infectious..
Now the HVAC (AC) system may or may not be a contributing factor depending on its design, and how well it is maintained and operated (humidity and fresh air settings etc).
However I do know enough about HVAC and wind pressure to know that HVAC and open doors/widows means that HVAC will not work as it is meant to.
The room doors are not airtight and so open balcony doors with wind pressure will mean that at times that air will move from the guest room into the hallways. Multiple floors and then liftwells and possibly stairways (doors may or may not be airtight) could lead to flushing of air between floors.
Now that may be acceptable when you are only concerned about a bit of extra energy used and that temperatures may be off a little, but for aerosol containment it is a no no as you want all the air to only travel through the ducting and to then be subject to appropriate humidity control and fresh air venting.
Open windows and HVAC is not really a prudent mix. A balcony makes the stay more comfortable, but it increases risk of aerosol diffusion both through rooms and from balcony to balcony and then into other rooms.
So for aerosol control balconies and open widows/doors are not a good idea for a building with HVAC that services all rooms.
With the mining camps hopefully all the cabins will have room AC so that people can sit on their balcony and also enjoy a cool room. Room AC is not a problem as long as people are not mixing with other people from other rooms. I personally have avoided restaurants that use room type AC units. ie the Smile Buffalo in Blackrock which help to fuel the recent Melbourne outbreak.