Another component that will need to be purchased in order to get the AC window unit to work in the car will be an inverter. The inverter transforms the cars 12V DC power source into AC. This component will allow us to plug in our AC Unit and run it care free. One major consideration that has to be understood before selecting the inverter is how many watts your AC unit is pulling continuously and at start up. Typically your start up wattage needs is 3-4 times that of the continuous rating. So for example the Frigidaire unit I am in the market for has an continuous output of 446 watts. The estimated start up wattage at 3X is equal to 1,338 Watts.
Knowing these figures we can now select an appropriately sized inverter that will be reliable in continuous operation during extended periods. This is one area I think overkill is probably justified. Here is a unit that would not have a problem running this AC Unit =http://www.invertersrus.com/pwrb1250.html
The Aims unit is priced at $99 and has a surge wattage of 3,500 along with a continuous wattage of 1,250. There are many inverters available for under $100 that would do the trick.
The good thing about my AC design strategy is it caters to the window units design. They are made to go into windows or walls. Since I will be building a wall separating the rear hatch from the cockpit the window AC unit is a no brainer for inexpensive AC for the Centurion. A big advantage here is that the electric AC can run even while the Kubota diesel is off
Another advantage is that we can come up with a solar power design that can help supplement the needed power for the AC.
Another major consideration will be venting the unit. This should not prove to difficult as we can take a similar approach to cars with rear mid engines like in the VW XL1.