Today I have only one zone on (as a test), up stairs sitting room which when that's on, a vent (exit) in the void entry comes on as well. It flows over the indoor balcony and down into the living which has a void ceiling (double height). Linked to the living (open plan) = dinning, kitchen, scullery and the games room. One lower bedroom door open as well, for the cat
Despite only one zone, all these areas are at a good cool temp. We have around 6 zones. 2 controllers, one downstairs and one up stairs in the passage leading from the master B/Room to the ensuite.