Car refrigerator with my own hands for 1000 rubles
2. So, let’s start with a container-thermos. We will need one sheet of polystyrene foam with dimensions 1200×600 mm, 50 mm thick, a clerical knife and a tape measure. The cost of such a sheet at any construction store – 160 rubles. We cut the sheet on a template, take the foam mounting and glue a container here.
3. Here’s the scheme of cutting the sheet. The sheet has 20 mm thick edges, they need to cut off all sides except the bottom. Sheets are glued to each other with foam. The technology is simple. Apply a bit of foam on the bonding area, wait 1 minute, press the sheets to each other and then within 5 minutes manually control that they have not moved due to expansion of the foam. The main thing is not to leave unattended. Only a small piece of styrofoam, marked in gray in the diagram, will remain unnecessary.
4. Pay attention to the design of the lid, one of the large sheets from the diagram above I cut into 3 parts on the spot when gluing to ensure a tight fit. After that, the outside of the box can be painted. The paint corrodes the styrofoam a bit, so it is better to paint in two steps. The resulting container weighs 820 grams and has an incredible performance on heat loss. You can put several kilograms of frozen food in such a box and transport it for several hours without any problems. The main thing is not to mix frozen and refrigerated foods. You can supplement the design with a battery of cold.
5. Or you can modify the design to get a full-fledged refrigerator. For this purpose, we will use a Peltier element – a thermoelectric transducer, which operates based on the appearance of a temperature difference when an electric current flows. Exactly such elements are used in commercially available automobile refrigerators, as well as car seats with ventilation.
The cost of one element of Pelte maximum power of 60 watts on aliexpress – 130-150 rubles. Model TEC1-12706. During operation, one side of the element is heated, the other – cooled. to element does not burn requires intensive heat removal from the hot side. To do this we will need a CPU cooler with a radiator from a computer store, which costs 250 rubles. To improve air circulation inside the cooler and to avoid freezing of the radiator, I decided to install fans on both sides. We also need a thermoregulator with an external temperature sensor and a relay for 170 rubles, which allows us to control the set temperature inside the container. And an extension cord with a car cigarette lighter jack for 100 rubles.
So, let’s proceed to assembly.
6.Install the Peltier element between the two aluminum heat sinks using thermal paste (supplied with the cooler). Here it is worth noting that it is possible to increase the temperature gradient of the installation by making an assembly of 2 or 3 Peltier elements installed in series. So that one Peltier element cools the other. In such a variant, it is realistic to get a negative temperature of up to -18 degrees Celsius in the container. Along the perimeter between the elements we put a piece of foam insulation.
7. We connect the radiators to each other with the standard motherboard mounting plates, connecting them with plastic clamps. This also allows for thermal insulation of the cold and hot sides. Test run the installation. The more we cool the hot side, the lower the temperature will be on the cold side. Here the fans are aimed at bringing air into the radiators, it’s less efficient than if you flip them to blow them out. The improvised box managed to achieve a temperature of -3 degrees, with an ambient temperature of +26. On the photo you can clearly see the model of the coolers, their advantage is the large area of the radiator support pad. And as an insulating pad I used a piece of thermal insulation for round pipes.
8. Now let’s deal with integration of thermoelectric converter into the new lid for the container. For the convenience of placing the whole structure we will increase the thickness of the lid to 100 mm (2 sheets of styrofoam). In this photo you can clearly see the perimeter gasket between the two radiators.
9. Artistic cutting of the styrofoam and sandpaper processing. Painting again. After painting, the outer shell of the styrofoam becomes stronger.
10. Seams are put through with sealant, both fans are blown out. For potential modifications we should probably decrease the speed of the fan on the cold side (now both fans are working at maximal speed).
11. Next to the case install the thermostat board and fix the power wire in this unpretentious way. First press the plate with self-tapping screws, then fix it with sealant.
12. Assembly of the container. Weight of the container without a lid – 800 grams, the same weight of the lid with a thermoelectric converter assembly. Total cost – 1000 rubles and a couple of hours of time. Tests with chilled food in the trunk of the car showed the ability of the system to maintain the temperature at the bottom (!) of the container to +5 degrees Celsius, at an ambient temperature of +29 degrees (yes, it is much warmer in the trunk, even with air conditioning) and current consumption – 3 Ampere. I think it’s an excellent result.
I plan to make my next container out of 3 Peltier elements installed in series to get a full freezer.
The refrigerator in the car with their own hands (3 variants, photo, step by step)
I do not know if I chose the right section, but decided that this topic is appropriate here. I suggest everyone share their experiences here HOME MADE.
I want to share with teammates experience of building a self-made, mobile mobile fridge. The thing very necessary, for trips on the nature and on the sea, naturally.
This year we will definitely go to the sea. “Brakes” and drinks, so they do not go bad, it is better to keep in the cold. And for this purpose the refrigerator is necessary. The “greed” doesn’t let me buy a car cooler from the cigarette lighter for 4500 r. Therefore, even for the old car, it was decided to make a new, capital refrigerator with “accumulators of cold” in the form of frozen water cans. The old refrigerator from the packaging cardboard has served 3 trips to the south, and was ruthlessly thrown away at the dumpster (picture attached below (not a dumpster and a refrigerator)).
So, what and how was done. The size of the fridge was selected 400 * 400 * 300 mm, based on the size of the trunk in the previous car (too big would take up a lot of space, and there would be nowhere to put things).
Insulate, or rather insulate, decided foam insulation with foil on one side, a thickness of 10 mm. The width of 1,2 m, the length of 1 m. Price today 90 p / m.
Material body was used as waste products from our furniture production – MDF (or, more clearly, fiberboard) thickness of 10 mm. Bought 2 aluminum corners 15 * 15 mm for 120 p. for both. Also bought rivets 4*16 (100 pcs. – 50 p.) and 2 furniture bar hinges for 30 rubles each. That’s all the costs – 295 rubles. Tools and equipment were borrowed at work (where the refrigerator was assembled).
Cutting off the corners on the spot, we slowly began to assemble the box of the future refrigerator.
As a result of this titanic effort we got such a nice-looking box.
I put a lid with a latching lock and a folding handle made of wire. So that the ready fridge with food can be carried in a hand. Otherwise, it becomes very heavy, loaded with water and food! But, as they say, one’s own burden is not heavy…
Now we are going to glue inside of the box with insulating material. I decided that the lid and bottom will be glued in two layers of insulation, and the walls in one layer. For gluing I used “liquid nails”. I smeared a piece of insulation with “nails”, glued it to the wall and pressed it with a weight. It glued well, then tried to tear it off – glued sealant did not give in.
As a result, after 3 days of work in my spare time (which is not very much), I got such a nice fridge with a flip top lid on the latch.
In the corners or on the bottom will be fixed or stacked 4 and a half liter bottles of water, or 6-8 half-liter bottles, pre-frozen in the freezer. It is possible to use mineral water as it is cool and with gas and it is very invigorating in hot weather. It is better to take half-liter mineral water as this volume is more practical. Otherwise, when the water freezes, the ice will expand and break the bottle, and the food will float in the thawed water. To save space in the refrigerator you can buy in a store brand “accumulator of cold” – these are special bags or flat boxes with liquid inside, which are used instead of bottles (one large costs about 120-150r.). Only bottles with spring water we have free! And even when the water in them begins to melt (which is after about a day), it can be used for cold washing or drinking.
Using the previous, cardboard refrigerator, foods and drinks not eaten or drunk on the way, reached the sea cold. In the new fridge we brought even our still ice to the sea, it did not melt completely! This fridge can also be used as a stool. I didn’t paint it on purpose, to be able to see if something happens to the MDF (for example, if it starts to warp from water). I’m completely satisfied with the fridge, it was worth the time and the small amount of money it took to build it. And the usefulness of it is very much.
Variant №2. Passive auto-thermos with my own hands.
I will say right away that this thermos auto cooler was invented by my friend Valera! For what we are very grateful to him. He lives in the south, we have hot weather, so auto coolers for products on vacation catastrophically lacking, especially if we go out with a large company. Valera made such a thermos-auto-refrigerator with his own hands a few years ago, so I decided to make a similar one.
Total, bought a box for children’s toys – 350 rubles, 2 sheets of foam 2×50 rubles = 100, two skeins of metallic adhesive tape 2×100 + 200, universal adhesive 80 rubles, foam mounting 120 rubles TOTAL 850 rubles and 2.5 hours of my precious time.
After two days of compote from a thermos on the Spit Dolzhanskaya, on board about 40 degrees, normal flight:
Option № 3. the active refrigerator on the Peltier element with my own hands
Consumables: 1) Peltier element (rarely used for cooling computer processors) 2) Old ESKY box 3) A pair of heat sinks from computers 3) A wire and a dick in the cigarette lighter.
Prelude: One boring evening, gently stacking computer jewels from one place to another. As fate would have it, I had Peltier elements in one hand and radiators in the other. And by some miracle, an old ESKY came into my sight.
In general, after beer beer came to mind a crazy idea. I built a fridge out of computer stuff.
Two radiators were taken, holes were drilled. Made a hole in ESKY for the radiator. I bolted everything together and got what I had. CPU cooler on the outside, natural convection on the inside.
Pros = 1) it works. Cons = 2) one element is small. 3) The cigarette lighter gets warm. 4) When it works, the cell not only moves heat from the inside – outside, but also generates heat itself. That is, (let’s assume) when the temperature of the internal radiator drops by two degrees, the temperature of the external radiator increases by four, five degrees … something else was, now I do not remember.
Conclusions: The elements should be placed on the cover (easier to install, the cold itself will go down). There should be several elements for at least some cooling. Use either “crocodiles” or T-shaped sockets. Cigarette lighter has not enough area for this (which causes heating). Radiators need a much smaller size (2/3 should be sawn off unequivocally), use a monoblock thinner, and wider (and if also copper . ). Well, I used what I had, actually.
Anyway. It was a pilot project, too, will be fine-tuned in the future for capacity.
Tip: Should combine the effectiveness of autothermos and Peltier elements instead of, or in addition to, cold batteries.
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