How can I build a homemade refrigerator?

Summary:There are many types of refrigerators. Dismiss all the ones using poisonous gases like ammonia. If you want a modern ref...
There are many types of refrigerators. Dismiss all the ones using poisonous gases like ammonia. If you want a modern refrigerator, all the parts are manufactured already and all you would be doing is putting together a kit to make a Franken-fridge. NO benefit. It's cheaper to buy the finished product. You could make an icebox, the forerunner of the refrigerator. That seemed to work OK to keep food cold until people wanted to actually have a freezer. For just an icebox, you needed a block or two of ice about a foot measure each as cubes. In an insulated cabinet natural convection caused the cold air to fall from the top, where the ice was located, cooling the produce on the wire racks.
Today, where do you get such ice cheaply? Did you ever use a can of Duster spray, a spray can that has carbon dioxide compressed until it is a liquid, then released as a stream of carbon dioxide gas to blow dust off of computers and electronic devices when you pull the trigger ? That is essentially a refrigerator. When you spray the carbon dioxide gas, it forces it through a small orifice at the nozzle. When you feel the top of the can, you feel it extremely cold. I would estimate that it is little lower than freezing temperature. Problem is, that while this is interesting in showing how a modern refrigerator turns gas into liquid then releases the pressurized gas through a tiny orifice in order to create extreme cold, there isn't enough to do anything with except perhaps spray on a bottle of medicine that needs to be kept cold in an emergency, by keeping it in a foam ice chest and hitting it with the spray periodically (with the can held upside-down so that the liquid, not the gas squirts out). Problem here is that a lot of dusters have embitterment chemicals in them to keep useless people from inhaling the concentrated vapors to get 'high'. It makes it horrid to use as the embitterment gets all over everything.Car Cooler Box Suppliers
You have thermoelectric coolers, but moist electronics tend to kill off the modules or the electronics especially if used in high humidity environments. You can get the modules, and you can attach them to heatsinks, and you can get a power supply and a thermostat, but after you've spent for all this, including the insulated cooler to mount it in, all told - it's cheaper to buy the finished product. While you can make a fridge, either it will be very limited usefulness or it will be a clunky, ugly Franken-fridge with poor insulative properties which will ultimately cost you more money through daily operation inefficiencies than if you bought the real-deal. If you need the challenge of accomplishing it, I won't dissuade you, although there are regulations now for the use of Freon gas that are beyond you or I when the government prohibits non-licensed people to fill or drain refrigerant.