We have very wide ducting on the ceiling of our kitchen which runs as a square around the inside portion of the cabinets rather than along the walls above the cabinets. We would like to minimally reduce the duct size in this area to fit above the cabinets snug against the walls so that we have an open ceiling above. Was this just poorly planned originally, or is there a reason we should not change this ducting? It will open up our kitchen above much more if we move it.

We have been remodeling our 1950's rambler. We took down a 8 foot section of wall between the living room (24'x12') and 3rd bedroom (aka dining room 10'x12'), This has now made an "L" shaped room 24' long by 12 foot wide on one end and 24' wide on the "L" end. In removing this wall we lost two cold air returns (one vent in each of the two former rooms. The simple soultion of placing a vent in the floor is a non-option as it would put a vent right in the middle of the new room. There are now 3 heating/cooling grills in the room and only one air return. The one return is located at the far end of the room in what was a small hallway but is now more open due to the remodel. My investigation shows that the return air duct runs under the floor of what was the smaller room about 26 inches inches into the "L" and on the other side of the wall above the furnace. So the return would tap into a main duct about 20 inches from the furnace. Is this the right option? I guess the other option would be to run a duct from the far "L" wall to that duct using the floor joists as the former ducts were but that would place the return close to the heating/cooling register. We're clueless as to what is the best option. We'd be happy to do nothing, but are pretty sure that one cold air return isn't going to cut it in such an open space. Any help would be appreciated. Thanks!