Build your own Air Conditioner

You can start with pretty much any cooler you may already have as long as it does not leak.
I started with a 28 quart cooler which I purchased for about $20.    I think I would reccommend using one just a little larger in order to hold more block ice.   This will help it to cool longer.  I am getting about 1 hour and 10 minutes out of a 10lb block of ice, but this will vary with the air temperature.  I like this size as it is easy to get in and out of my Cherokee.  I flew with it today for the first time and it is cold.  The air temp was about 88 and I turned it off once I reached altitude.  I then turned it back on when I started my descent.   NICE  !!!
               If you fly a low wing then you know what a greenhouse they can be.  They get hot. 
List of Materials
1-28qt or larger cooler
1 -4 inch bilge blower 240 CFM 12 Volt ( Mine is a Seachoice  41841 )
1/2 inch styrofoam sheet ( old foam ice chest or house insulation )
1-3 inch thin wall PVC pipe coupling
1-lighter plug
8 OZ fiberglass cloth
resin ( I like West System but use what you have )
1-auto heater core
1-Rule 500 gph 12 volt bilge pump
6 feet bilge pump house ( cheap plastic )
3 inch flexible aluminum dryer vent hose ( length to suit )
1 tube 5 minute epoxy
1- small can minimal expanding foam
8ft-2 conductor wire 16GA

Finished Cooler
Finished Cooler

To begin ,cut out a rectangular hole in the top of the cooler , both the outside and the inside.  this will leave you a hollow frame about 2 inches wide all the way around.  A sabre saw works well for this.  The dimensions of your heater core will some what determine the dimensions of the hole.   Heater cores come in all sizes and your auto parts store should have a book which gives pictures and dimensions.  Pick one that fits your needs. Cover the fins of the coil with duct tape on both sides and then foam it in place using the spray foam.  The tape will keep any excess from getting into the coil and make it easy to clean off.  Once the foam is cured remove the tape.   Using the foam sheet build a box over the coil about 3 to 4 inches tall . Use the 5 minute epoxy and tooth picks to hold it together until the glue dries. One edge of the box should be right over the end of the coil in the middle of the lid and should just touch the coil.  This will be the divider between the inlet and outlet sides and needs to be sealed to force all the air through the coil.  Butted up to it, build a foam box to cover the rest of the opening in the lid, making sure the 2 - 3 inch pvc couplings will have enough room to fit in the top of it.  Looking at the pictures will help you see what I am speaking of.  Cover the Lid of the cooler with duct tape and place the boxes in place on top of it.  Glue both boxes together with a couple of very small dabs of glue holding them to the top of the cooler.   Place some weight on top and let the glue dry. Caution, do not solidly glue the boxes to the lid as you will need to remove them later.  After the glue dries use a rasp or sanding block to shape the foam to your taste.  Rounding the edges helps the fiberglass to lay down better.