yeah, most anabatoids prefer warm moist air, cold dry air can lead to infections even in adult fish, but to be honest the humid air will settle in the area above the water, it really only becomes a problem when you have them in a freezing cold shed or something. Never seen those tanks before, but look cool, would like to take a gander to see how they are set up, if you like that sort of look the Aquaone nano cubes are pretty good with a descent filter system all hidden away in the back. I would recommend a lid anyway, better than finding you betta on the ground.
good to drag another lurker out of the shadows