Here is an easy cheap air conditioner that anyone can make.
Step 1: Inline Vent Fan
Use an inline vent fan from your local hardware store. You don't want the fastest fan as more time the air circulates in the box the cooler it becomes.
Step 2: Exhaust Vent
For the exhaust vent use a 90 degree vent pipe as it can be redirected in almost any direction by easily spinning the sections.
Step 3: Cut Holes for Vent
Cut the holes in your lid to your chosen tub by placing the fan and the exhaust vent on the top and tracing it with a felt marker. Cut the holes slightly smaller so the vent and exhaust pipe fit tight. Using a Rubbermaid bin makes the cutting and fitting much easier as the lid is made of rubber and not plastic so it can be easily cut with a utility knife where a plastic lid would be a bit more difficult but still possible.
Step 4: Insulate the Tub
I used 2" pink styrofoam insulation to insulate the tub bottom, 1" insulation for the walls as I wanted the most space possible for ice. Cut the styrofoam bottom first and wedge it tight in the bottom, then cut your long sides to fit tight and finally when you cut the short sides you will force them in and it will wedge the sides open and become strong and solid. You can use any type of styrofoam insulation. I found the pink type to be the most ridged and has an R value of 10 for 1" and 20 for 2"(bottom).
Step 5: Install the Piping
Fit the vent pipe and the exhaust vent pipe into the holes your cut and use some hot glue to secure and seal the connection to the lid.
Step 6: Put in Your Ice Containers
Use jugs of any type to fill and freeze water. Have lots of extras in the deep freeze to exchange with.