My wife has been asking me why there hasn't been a portable AC we can use in our trailer that runs on 12v. Did some searching and found couple that were an arm and a leg until the other day a Kickstarter campaign advertised itself on my FB feed. So I figured... Might be worth a risk. Figured someone else might be interested as well
60.8°F Maximum Cooling | Bluetooth Speaker | Emergency Light | Power Bank | Indoor&Outdoor Use
chilfeed-4-in-1-portable-air.kckb.st
Btw, had anyone ever did a Kickstarter purchase? Kinda intrigued by the process.
Let's talk basic thermodynamics. For starters, you are not necessarily adding cool air, but rather you are removing the heat energy from one area, and must move it to another. This process involves compressing an energy absorbing gas, the compressed gas is passed through a condenser, and has air blown accross it releasing its heat load, this is done OUTSIDE of the space to be cooled. The big box outside of your house for example. The gas, at this point in a liquid form flows further along the lines through an expansion valve, sort of like a spray nozzle, that turns the refrigerant back into a gas, dropping pressures, and temperatures massively, the refrigerant is now COLD. It then goes through the evaporator. Air from the space to cool is blown accross the evaporator, where heat exchange takes place, the heat is pulled from the air, and goes into the refrigerant, where it cycles back to the compressor and the circle starts over again.
In this process, the compressor uses the most energy, the fans blowing the air accross the coils, condenser, and evaporator, are lesser, but they all pull a fair amount of energy.
To be blunt, you could in theory convert an AC to 12v, the amperage draw would be so massive, you would be pulling at minimum 40 amps. NOT something you would want to run that very long off of a battery setup.
So long story short, the tech isn't there for an effective, efficient 12v air conditioner system. Now there are some technologies that are not in production that MIGHT help out with this. Rotary compressors instead of piston compressors may require less energy, I really don't know for sure... And even at that point, how to make a rotary design efficient and reliable. They tried it with engines and failed due to the weak point, the apex seal. AC compressors are a similar problem...
Every single unit you see on the market that does NOT have one side inside, and one side outside of the space to be cooled, is NOT going to work efficiently.