Why is it best practice to avoid installing roof louvers or wind turbines on multiple sides of a roof above a common attic?
It is best to keep roof louvers or wind turbines on the same side of the roof.
The reason it is best practice to keep roof louvers (sometimes called box vents) or wind turbines on the same side of the roof (above a common attic) is because of wind dynamics. Depending on the direction of the wind at any given moment/time of day it's possible that the roof louvers on one side of the roof could perform as intake vents while the roof louvers on the other side of the roof could perform as exhaust. That is not efficient airflow for the attic and risks weather infiltration through vents that are not designed to ingest anything.