Here is what I learned with having a tent AC.....
I thought I would wait until we got down to Orlando and pick a A/C up at
WalMart to cut down on weight on the way down. well since most homes in FL have central air, room A/C units are not big sellers and Walmart didn't carry them. Luckily Kmart up the street had some.
Make sure that your tent is not "to vented"
We bought a huge cabin tent and one of the features is the way it is vented.... not good if you are trying to cool it off with a AC, our old tent would work much better with the A/C since it is not as vented.
A good silver vinyl tarp over the top of the tent helps keep the cool in the tent, and makes the tent much more resistant to wind, and vertually rain proof.
Most tents nowdays have a shoe door, this is what I used for the A/C vent, was big enough luckily without having to cut or modify the tent.
If we used the room dividers, we could keep half of our 10' by 14' "vented" cabin tent pretty cool. It was nice if you did get to hot and just needed to cool off for a bit, and I did sneak in a afternoon nap or two. If the tent wasn't vented the way it was we could of easily kept the whole tent cool. Next trip we might break out the Dome tent and use it since it is more airtight.
Oh yea, bring a big roll of duct tape!
Good Luck!
Mouse Brain