That really looks like a nice tent air conditioning arrangement. I may try to do something similar. We have a Little Guy with the attached screen room tent. The tent snaps on around the passenger side door. One problem is the side of the tent around the door is a screen mesh material open to the outside. The tent is not made with a way to close up that side when it is attached to the trailer. So the tent temperature is pretty much always the same as outside. There is a solid flap, but it needs to stretch over the trailer to keep rain out of the tent and it cannot drop down past the trailer door.
I might try to Velcro on a solid piece of tent fabric to seal up that side, if I can find a source for that type of fabric. Then an A/C setup like yours or a heater could do some good. We usually leave the trailer door open on the tent side because our cat, Paige the camping kitty, likes to go back and forth between the tent and trailer.
There is a photo of the trailer and tent in my album, page 2. I would appreciate any ideas on sealing up the trailer side of the tent.
Bill
PS My response is two years later, I wonder if anyone is watching this topic now. Still a great idea!