The author needed a small refrigerator that could be used in a car. After going over the shops and finding out the prices for such appliances, he was struck by the idea that it would be possible to create a homemade mini fridge would be much more preferable than buying a branded device. Therefore, evaluating the materials he had that could be useful for creating a home-made auto-refrigerator, I decided to proceed with the assembly of such a device.
Materials:
- a water cooler that has failed
- the Peltier element
- heat-conducting paste KPT-8
- radiator
- fan
- computer power supply
- polyurethane foam
- metal mounts with bolts
- foil
- switch and additional wires.
- fan thermostat
Description of the manufacture of a car refrigerator do it yourself.
Step One: Choosing a Refrigerator Case
As the main part of the case of the future refrigerator, the author decided to take his existing case from a non-working cooler, or rather its lower part.
Here is the whole cooler photo:
This car cooler will be made from this part of the cooler:
This is his front view, and this is how he looks from behind:
Step two: finalization of the refrigerator body.
Choosing a case for the future refrigerator, the author began to modernize it to fit his needs. To begin with, the cooler was disassembled. The top of the plastic shell was removed. Since the standard door fasteners were there, he had to make his own fasteners. For this, several bolts and a pair of metal plates were used. As a result, we got such unique loops on which the door of the refrigerator chamber is held.
Step three: selecting and installing a cooling element.
As a cooling device for the refrigerator’s chamber, the author decided to use the Peltier element. In general, almost all modern models of refrigerators, for use in car, work on just such a principle.
Fourth step: creating a cooling system for the element.
It is very important to attach the Peltier element as tightly as possible to the cooling radiator. To better transfer the heat generated by the reverse side of the Peltier element to the radiator, the use of heat-conducting paste can help, he used KPT-8 paste. and attached both the upper and lower parts, for a more gentle operation of the element.
Step Five: Connect the power to the refrigerator.
As a power supply for this device, I used a computer power supply, or rather a power supply for a laptop, as it is quite convenient and can be brought out. The main thing is that this power supply is able to supply a voltage of 12 V, as well as a current strength of 5 A.
During operation, the power supply can become quite hot, therefore, the author considered that it would be more expedient to bring the power supply out of the chamber of the future refrigerator to preserve the cold in the chamber.
Step six: work on thermal insulation.
In order to minimize heat transfer from the device to the inside of his refrigerator, I decided to fill the back wall of the refrigerator with a mounting foam.
And also, in order to maximize the preservation of the cold environment inside the refrigerator and to avoid heat transfer from the outer walls, I covered the inner walls of the chamber with foil.
Seventh step: installing a fan and creating a thermostat for its operation.
A fan was mounted on top of the radiator to which the Peltier element is attached. Thus, active cooling of the radiator and the element itself will be carried out, respectively. And in order to regulate the fan speed, the author found a temperature regulator circuit, which, depending on the temperature of the radiator, can reduce or increase its rotation speed.
Thermostat diagram for controlling the operation of the fan:
You can also watch the video that you shot, there you can find out a few additional nuances, as well as fragments of work on the refrigerator during its assembly.
Video of the author about the creation of this refrigerator: