Skooter, I LIKE your "Cool" box. What if, you visited the nearest precious metal yard (Junk Yard to some) and rescued a air to air intercooler from say a Subrua WRX. Pipe the intake outside the cooler, outlet tied to the directional pvc fitting. Cover the intercooler with dry ice (I used to get it free from the back dock of a local big chain grocery). Dry ice is -109 F, pretty stinking cold. Plumb a vent pipe from the upper part of the cooler to the outside and seal the cooler so ALL the CO2 vents to the outside. Turn on the blower and Chill.
Only flaw in the above is you would have to be pretty anal about controlling the CO2 released by the melting dry ice. Gotta vent it outside and gotta seal the ice chest. It's not poisonous like CO, carbon monoxide, but CO2 like any gas that displaces the oxygen we need can produce very serious results in a small space.
The big plus with dry ice is it should last much longer and produce much cooler/colder air.
Last idea, build the cool box with a intercooler, fill it with water, stick the whole thing in the freezer and freeze. When hitting the road throw it in the truck and enjoy. By totally encasing the heat exchanger with ice it would be super effective I'd think.
Fun project, thanks for the ideas.
Good Luck,
RonR
I build dry ice manufacturing plants for a living. We have to vent them to replace the air in the entire plant every 15 minutes. It is dangerous stuff. I would not put in in your truck under any circumstances. You cannot smell it and won't know you have a problem until it's to late. When I was young and lived in the Sol-cal desert I used to put my 6 pack cooler under the cowl vent full of ice. It wasn't great but it helped.
