A satsuma. The penultimate element of my lunch.
The ultimate will be a banana, in a few minutes.
The 1983 UK general election.
However, since I lived in a Tory safe seat (taking boundary changes into account, the last time that location had been anything except tory was a Whig in the C19th) I spoiled my ballot - writing some pithy comment across it about how meaningless the process was. That showed them!
Checking now, I see that it has continued as a Tory safe seat up to the present day.
If these were lab conditions with known airflow and volumes and window sizes and air temperatures and solar gain and so on and so on maybe someone could give you a useful answer, but without any of that, I’ve no idea and I doubt that anyone else will be able to tell you either.
Cold air will enter the stairwell at the bottom. If it is cold outside, it will probably be at least a bit warmer in the stairwell, so the air will warm and rise to the top of the well. It’s probably still cooler than in anyone’s room, though so that will be what the 4th floor residents are noticing.
To air the well most effectively, I’d suggest opening a window at the bottom and at the top and maybe putting a heater at the bottom as well. That would cause the cold air entering at the bottom to rise more rapidly and then exit through the top window. This may not be particularly efficient from an energy use POV though.
With the top window open and the warmer air in the well the 4th floor may even get less of a draft doing this, as the air would be getting out that way instead - unless there was a wind blowing in through that top window.
