Circulating air between floors
I don’t see a lot of air mixing between floors in my (partly finished) house. We had a hot day here yesterday (34C / 93F), and by sunset the first floor was 22C / 72F while the upstairs was around 24.5C / 76F. This doesn’t surprise me, as hot air obviously rises, plus the 1st floor has the benefit of the slab heat sink. What surprised me is that this morning the temperatures were the same. I would have thought with minimal heating going on during the night, they would have equalized at least somewhat. (There was no cooling last night, it never went below 24C and I woke up at 6:45 to a temperature of 27C).
We have a wide, straight stairway in the centre of the house. Would it be worthwhile to put a duct between two communal areas of the two floors and a duct fan? Or would this be a lot of work for minimal benefit?
Note: we don’t have the HRV running yet, but my understanding is that wouldn’t mix enough air to make a lot of difference.