I don't know what you have so I don't know if my story helps, but I have done this. The original AC system in a prior TT did not have anything but the vent system. I wanted to be able to dump the air straight down without using the vents. I went online and looked up my model AC and found out you could buy a replacement AC cover that included vents (mine was solid and did not) that would allow the air to go straight down when open and thru the vent system when closed. Replacement AC cover cost about $60 and took 10-15 minutes to install. Threw the old AC cover without the vent system away. Bottom line - try to research your AC model number and see what covers may be available that have vents built in. Good luck.
