Introduction: Building a Tiny Fridge for My Tiny Dorm Room.
I'm just finishing up my first year studying abroad in Australia. I'm currently living in the most basic student housing, which is great socially, but has a few minor drawbacks. Mainly, I'm sharing a fridge with about 20 other people, which is doesn't offer a lot of space. Plus, we all know food has a tendency to disappear on you when living in community. My inspiration for this project is mainly frustration with my having my food stolen.
- Eskie/Cooler/Icebox (alternatively any container with good insulation)
- 12v Peltier Cooling plate
- 2 Passive Heat Sinks
- 12v PC Cooling Fan
- Electrical Tape
- Various Screws
- 12V 5A DC power supply ~Please note that the power supply I'm using is only 500Ma. This is only a placeholder to run the unit for a few minutes at a time. It will be replaced as soon as the 5A power supply arrives in the post.
I have limited tools in my dorm, so I'll only be using a Leatherman and splicing wires instead of soldering, If you are able to solder, that would definitely be the better option.
Step 1: Test & Visualize
There are a couple things to consider when plotting out the design of the project. Firstly the amount of cooling units needed is based on the size of the eskie you're using. My eskie is 6L, and the peltier plate surface cools to about -3C ; so I'm confident one will be adequate. Secondly positioning of the cooling units. I wanted mine to be integrated into the lid to keep a lower profile, and to allow the heat to rise and vent away from the rest the unit.
When testing the circuit, its important to take note of which side of the peltier plate is the "Hot Side" and the "Cold Side." Keep in mind that reversing the polarity will change the orientation of each side. The Peltier plate will be sandwiched between the two heat sinks, with the "Cold Side" facing downwards. The 12V PC fan will be used to ventilate the the "Hot Side."
Step 2: Cutting & Mounting
This step may be more or less complicated based on design. For me, it was probably the most time consuming step, as I only had a pocket knife to do the cutting and filing. I started by tracing the smaller heat sink on the bottom of the lid, and cutting from that side. I did the same on the other side with the larger heat sink, being sure to line up the screw holes on both. I then drove 4 mounting screws up from the bottom to hold the smaller heat sink in place. I finished by filing the screws down.
Step 3: Wiring & Splicing
My peltier plate came with a little piece of adhesive foam to insulate it between the 2 heat sinks, however this isn't absolutely necessary. I had a bit extra, so I put it around the smaller heat sink also.
The wiring is super simple. I started by running the power supply lead into the lid through a small hole, and up through the large hole I cut earlier. This is just so I the wiring will be mostly contained within the lid. Again, I don't have a soldering iron in my dorm, so I'm going to be splicing instead. I spliced the the red lead from the peltier plate with the red lead from the 12V PC Fan. I did the same with the black leads. I then spliced the corresponding leads from the power supply. A useful technique for this is called the "Lineman Splice." I finished by insulating any exposed wiring with a hardy amount of electrical tape.
Step 4: Gluing & Assembling
My peltier plate also came with a little bit of heat resistant glue, again its not necessary, but i decided to use it anyways.This step is really just a matter of securing the peltier plate in place, and adding the finishing touches. The heat sinks sandwich the peltier plate(ensuring that it is orientated correctly), and are secured with two screws. The PC fan is held in place with a couple more screws.
That's pretty much it.
Thanks for checking out my project, feedback is always appreciated.