The Tundra Freeze is not an AC unit as they claim. The so-called portable AC unit is a swamp cooler. They operated on "water curtains" which had to be filled with water and then placed in the freezer before inserting into the unit, rather than filling the unit with water as advertised.
The Tundra Freeze Portable AC
Once inserted in the unit, the frozen water curtains last only about 30 minutes before they need replacement, and the cooling effect is not adequate.