I am planning to run an 8" round conduit from basement to attic and in attic - split that into four 6" conduit and take it into the middle of 4 bedrooms in the 2nd floor.
An inline duct fan near the bedroom ceiling vent will pull and an 8" duct fan in the basement will push. I will need to figure out how to have a valve system in place so that only the valve to the 6" duct will only open when the fan on that duct works. Then I can time (take turns) to run the fans in each bedroom. Basement push fan always runs.
This will bring the cold air from basement into the 2nd floor and keep the house cooled.
In winter I will reverse the process so that hot air is brought down to the basement and will naturally rise again to keep the house warm (rather than escaping through the attic
is this a good plan.