I've been studying dead vents today. It looks like I could add one to the rear center of the HT room, about a foot shy of the ceiling so a projector can be placed on top of it. A vent either high or low in the HT room, with the other end venting towards the HT door on the outside of the room. Perhaps it could be wired so the built in fan would come on/off with the furnace fan, with a bypass switch that would allow you to either add or expel air at will, or to shut it off. I don't know if that's possible or not, but it seems like it should be.

At least that should solve my problem of how to get an HVAC return installed.

https://docs.google.com/spreadsheet/ccc?...amp;usp=sharing