Building a mini fridge

[Mutant Funk Drink]

I'm getting tired of my sister and parents eating the shit that I buy from the grocery store, even when I tell them that I don't want them to eat it. I need a place to put some of these food items. Preferrably a fridge.

When I'm talking about a mini fridge, I'm not talking about one of those 1' by 1' fridges that can only hold a soda can. Those suck balls. I want to build a small refrigerator that will hold a few drinks, some jars of stuff, a loaf of bread, and some other snacks. That way I can have this stuff readily available in my lair where nobody can touch it but me.

I've found something similar to this, but it's smaller than I want it to be.

http://www.instructables.com/files/deriv/FG6/1UQH/F9AZJTBH/FG61UQHF9AZJTBH.MEDIUM.jpg
http://www.instructables.com/id/5-Mini-USB-Fridge!/

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Apparently I'd need to buy a cheap peltier off ebay. The thing is, I'm not sure if it will get cool enough for the size that I want it to be. Should I try using a peltier or should I build it a different way?

EDIT: I don't plan on making it USB powered. The fridge in the video just happens to be for a USB fridge.
I'd also like to make it around the size of a dorm fridge.

[MunkeyQ]

Don't bother making it USB powered - since each port can only supply 2.5 watts, that isn't enough power to make an inefficient Peltier actually move a decent amount of heat...

...and inefficiency is where the Peltier falls down. It's fine for a small thing like a cooler as the current needed is within practical limits, but if you're wanting something larger, it gets impractical. You'll be looking at using multiple high powered elements, a huge power supply and a lot of heatsinking on the hot side with forced cooling. To get the fridge to a decent temp. below ambient, the elements need to be in a cascade configuration...basically stacking them up. Otherwise, a number of single elements will only be able to get 10 degrees C or so below ambient.

It is possible, but the power supply will be expensive - say you have four 12v elements rated at 150w input (about the most powerful you can commonly get), that's 50 amps needed in total! Other drawbacks are that it'll be very noisy from the fans cooling the hot side. Only around 50 watts of the input power actually translates into work done as a heatpump, so in addition to the heat moved, there's 100w of heat to get rid of.

So in short yes, it will get cool enough but it'll be noisy and the power supply will have to be massive.

The other way of making a heatpump is a phase-change system like what a normal fridge and AC uses. This is much more efficient but it isn't really practical to make at home as you need to get the system charged with refridgerant and keep it there. Bad silver-solder joints will show up rather well.

[Christ puncher]

You should skip the whole making it yourself and get one off of craigslist or something of the like. Then add a lock or electrify the handle.

[IIIII]

Tell your sister or parents to hold whatever close to their cold cold heart to chill it for you.

[Mantikore]

just get an icebox/esky and store ice in it. constantly make the ice in your freezer. im sure they wont eat your ice

[MunkeyQ]

EDIT: I don't plan on making it USB powered. The fridge in the video just happens to be for a USB fridge.
I'd also like to make it around the size of a dorm fridge.
If it's that big, you'll need a serious amount of Peltier power and you probably won't be able to sleep with all the fans needed to cool the hot side.

You're best off buying a fridge and protecting it as the others mentioned.

IIIII - you've just made me laugh, welcome to my signature.