DisneyRose - What was your a/c setup like? And did you leave it on all day?
So far I have seen/heard about the McGyver version (very cool!), the boot (way too complicated/expensive) and the just zip it in the door method(which I may try, since we are new).
Wondering how yours was to get it that chilly

Any pics?
Our tents all have 2 doors, so we used the "back" door for the a/c. We stuck it on a wire outdoor end table, plugged it inside the tent, and zipped the door as far as we could. The rest of the opening we simply stuffed a couple rain ponchos around and duct taped those babies to the a/c and the table.
We did NOT leave it on all day. When we were getting ready to leave for the day, we simply turned it off, unzipped the windows a bit (not too far because of the rain factor), and went our merry way. When we turned it back on later in the afternoon, it cooled down fairly quickly. By nightfall, it was downright frigid. My glasses steamed up every blessed morning when I ran from my cot, through the maze of kids, and out the door into the heat.
We had an extra tarp over each tent, so that probably helped keep the cold air in, but who knows? I'm not all that into the physics of the thing: all I know is that, boy oh boy, did it work well.
And I do have a couple pics, but I have to figure out how to get 'em on here.

Once I figure that out (I'm hoping I can just copy and paste into a message), I'll put up a couple shots of our set-up (minus the huge lime green Mickey-head-table-cloth-sign-thing... that's THIS summer).
Anyway, I hope that helps!
Rose