We bought a really clean and nice 20'er with doors on both ends. W/o the double doors there's no air movement inside and it's hot and muggy to be inside. They have waterproof air vents so I'm not sure why guys are mentioning running out of air if locked inside.
We store seldom used items like Christmas, Halloween, Easter stuff plus lawn and garden chemicals, tools, mower, spare air handler, etc. They'd make a great watertight workshop if you parked it in the shade and installed a little air conditioner in one. Little woodstove for burning scraps, recliner and some LED lights and momma would have to bring you sammiches to keep you alive.
