I used circular vents for the ceilings, simply because I thought they were nicer looking than the square floor-style vents mounted upside down. There are two 5″ vents in the main room, one 5″ vent in the laundry room, and a smaller 3″ vent in the bathroom. For all but the bathroom, I just used the previously existing vent lines, but cut them shorter and used 5″ flexible duct to connect them to the vent in the ceiling tiles. This made it easier to hook up, and possible to move the tiles later without having to disconnect everything.
You can see the completed vents in yesterday’s post.
Since the bathroom didn’t exist as a separate room before I started, I had to add a new vent line for it. I thought this was necessary, just because of the way I split up the rooms – the only remotely close vent to the bathroom is around the corner in the laundry room, and if the door is closed then there is nothing.
The main ducts run just outside the bathroom door, so it was relatively easy to add a new line for the bathroom. I just added a 4″ collar into the side of the duct, and then used a reducer and flexible 3″ vent tube to bring it into the bathroom. I’m using relatively rigid pipe for this, not the thin flimsy stuff you’d find on the back of a dryer. The below pictures are older, obviously, and are from in the bathroom, looking out at the top of the doorway.