I am removing a drop ceiling and have a heating/cooling duct to hide. I would like to reroute it across the celing in center of the room to the present upstairs vent. Right now, it angles across the room from the furnace duct coming up through the wall from the basement to the vent. Can I reroute it and have two 90 degree angles. I believe this would look nicer. I was thinking of using insulated flex duct and boxing it in with wood along one wall and the ceiling. Can I use the flex duct for ease of use and can I make the 90 degree turns without over restrictiong the air flow? The room is on the first floor and is about 10x12. Thank You.