fix is this. Buy a big window unit.16kbtu at least. Frame up the side door. Make a sliding rack sturdy well made. When you get to track slide out have a little tarp hanging down on lower half of door. Yeah you have to duck into door but that ac works good. The 2 ac way uses the mess out of a big generator. The best thing to do is roof unit save all the trouble. Park the trailer outside. Heck that is why I have trailers to free up garage space lol. To each his own. I wish the best for you there are some videos out there showing the problem you will have. I thought I could overcome them buy building an insulated box around ac unit. It didn't work. Mine is a double hose 18k btu unit. When you get it all set up you will notice it only works if you never open a door. Put unit in my house it cools it down no problem. Like I said this is not a new discussion and sounds like you are like me got to prove it to yourself. Out of 15 20 times using this method only 1 time actually cooled and I found myself worried about making trailer cool rather than race. I wish you luck. Let us know how it goes and went.
no sir, and you can put something over it if you want to
Another answer would be exhaust vents for garage doors with swing covers for when not in use.
