I have dogs. It’s hot in Arizona. I’m thinking of getting a truck. I heard last week that it’s possible to install an air conditioner on top of a truck shell. Yes? No?
I’ve never heard of a standalone 12v air conditioner, and it would take a monster invertor to run a 120v one. I believe the big air conditioners for RV’s run on AC power and you have to have the generator going to run them.
What you could do, if your truck’s AC is in good condition, is get a well insulated shell with sliding glass and put weatherstripping between the back of your cab and the shell so there’s a good seal. With the shell well insulated and the windows sealed, your vehicle’s AC should be able to keep your dogs somewhat comfortable. A small fan placed in the sliding window may help circulate the cool air back, as well.
I’ve known people who’ve heated a truck shell thusly, with good results, though I’m not so sure about air-conditioning it. The way I figure it, though, your truck probably has identical AC equipment to the SUV version of it, which adequately cools a similiarly-sized area as your cab and shell.