Beating the heat and humidity with 5K btu window AC

Due to high daily temps and near complete saturation of humidity in my area I'm forced to create my own little micro climate....I envy you guys up north in this aspect.

The area I have available to me is in the garage where there is no heat or airconditioning. Temps will range 0-100 and the humidity will likely do near the same.

I had thought about a tent, but I couldn't imagine getting the control over the climate needed for a good grow. Instead I opted for a resin shed similar to this. Mine is a little larger, measuring 6'6" x 10' x 6ft tall inside.

Today the the interior of it was 93 degrees and 92% humidity! Nice eh...lol
Anway, I ran a little test to see just what a 5k btu window AC would do. I sat the AC in the doorway on a small file cabinet and put up plastic sheeting to cover the opening around the unit.

I ran it for 1 hr and the temp and humidity were considerably better.

This little test was far from a nice controlled "Myth Busters" experiment, but I think it shows there is hope for this type setup. My thoughts are that by insulating the shed I will see a marked improvement, and by putting the AC through the shed wall and out a hole in the garage wall, where it can vent it's heat away, I will see even better results.

Share your thoughts on this please. Really, share your thoughts preferrably before I cut a new hole in the garage wall!

Also, I have seen window AC units in the past that have a lever or switch to allow the user to decide to vent or recirculate the air....mine doesn't have one of those nifty gadgets. Is there any way to figure out if it is exchanging air outside or recirculating?

Maybe spray some airfreshener or cologne on the outside of ithe ac unit and then run inside to start sniffing? That has the potential of becoming one of my "hold my beeer and watch this" stories.

Any and all advise, thoughts, links, or pix appreciated.

This setup should work just fine and help you control your temps. I used the foam that you can pick up at any home improvement store in sheet form and tacked it to my walls and had a special exhaust built cause my room was in my basement wish I had pix cause it was one crafty setup. My setup didn't last long due to some sky rocketing electrical bills, so I went for the reducting of the HVAC system instead but you are on the right track and this should work fine for you as for the reciruclating sorry but dont know much about that.

I was thinking the 2 inch foam panels. Tacks won't work in my situation, but maybe some thin plastic strips laid at top and bottom and then drywall screws through both the plastic and the foam.
Maybe taking apart the AC unit itself will show the course the air takes through it. I'll give that a try and take some pics to share for any interested.