How to make your own car refrigerator. Which car refrigerator is better or how to make it yourself

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Option #1. Do-it-yourself passive thermos

I don’t know if I chose the right section, but I decided that this topic would be appropriate here. I invite everyone to share their HOME MADE experience here...

This year we will definitely go to the sea. It is better to keep the “brake” and drinks in the cold to prevent them from spoiling. And for this you need a refrigerator. Buy a car refrigerator from a cigarette lighter for 4,500 rubles. “toad” doesn’t give me any. Therefore, also for old car, it was decided to make a new, major refrigerator with “cold accumulators” in the form of frozen one and a half buckets of water. Old refrigerator made from packaging cardboard, it lasted 3 trips to the south, and was mercilessly thrown into the trash (I attached a photo below (not the trash, but the refrigerator)).

So, what was done and how. The size of the refrigerator was chosen 400*400*300 mm, based on the size of the trunk in the previous car (too large would take up a lot of space and there would be nowhere to put things).

I decided to insulate, or rather thermally insulate, using foam insulation with foil on one side, 10 mm thick. Width 1.2 m, length 1 m. Price today is 90 rubles/1 m.

The body material was waste from our furniture production- MDF (or, to be clearer, fiberboard) 10 mm thick. Purchased 2 aluminum corners 15*15 mm for 120 rubles. for both. Also purchased were rivets 4*16 (100 pieces - 50 rubles) and 2 furniture bar hinges for 30 rubles each. each. That's all the expenses - 295 rubles. Tools and equipment were borrowed from work (where the refrigerator was assembled).

Cutting off the corners in place, we slowly begin to assemble the box of the future refrigerator.

As a result of the “titanic” labors we got this nice little box.

I installed a snap lock and a folding wire handle on the lid of the box. So that the finished refrigerator along with packaged food can be carried in your hand. Otherwise, full of water and food, it becomes very heavy! But, as they say, you don’t carry your own burden...

Now we proceed to pasting the inside of the box with insulation. I decided that the bottom and lid would be covered with 2 layers of insulation, and the walls with 1 layer. I used liquid nails for gluing. Having smeared the insulation blank with “nails,” I glued it to the wall and pressed it down with a weight. It stuck well, but then I tried to tear it off - the glued seal did not give in.

As a result, after 3 days of working in my free time from my main job (of which there is not so much), I got this nice refrigerator with a hinged top lid with a latch.

4 and a half will be fixed or placed in the corners or on the bottom liter bottles with water, or 6-8 half-liters, previously frozen in the freezer. Can be used mineral water, cold, but with gas, in the heat it’s so invigorating. It is better to take half-liter mineral water, this volume is the most practical. Bottles are not filled with water full, otherwise, when the water freezes, the ice will expand and tear the bottle, and the food will float in the thawed water. To save space in the refrigerator, you can buy a branded “cold accumulator” in the store - these are special bags or flat boxes with liquid inside, which are used instead of bottles (one large one costs about 120-150 rubles). Only bottles with spring water are free! And even when the water in them begins to melt (and this happens in about a day), it can be used for cold washing or drinking.

Using the previous cardboard refrigerator, food and drinks not eaten or drunk along the way reached the sea cold. We even brought our own ice in the new refrigerator at sea, but it didn’t melt completely! This refrigerator can also be used as a stool. I didn’t paint it on purpose, so that it would be visible if something happened to the MDF (for example, if it started to warp from water). I am completely satisfied with the refrigerator; it justified the time and small money spent on its production. And there are a lot of benefits from it!!!

Option #2. Do-it-yourself passive thermos

I’ll say right away that this thermos auto-refrigerator was invented by my friend Valera!! For which we are very grateful to him. He lives in the south, it’s hot here, so there’s a catastrophic shortage of auto-refrigerators for food on vacation, especially if we’re traveling. big company. Valera made such a thermos auto-refrigerator with her own hands several years ago, so she decided to do something similar.

In total, having bought a box for children's toys– 350 rubles, 2 sheets of polystyrene foam 2x50 rubles=100, 2 two rolls of metallized tape 2x100+200, universal glue 80 rubles, mounting foam 120 rubles TOTAL 850 rubles and 2.5 hours of my precious time.

Two days later, compote from a thermos on the Dolzhanskaya Spit, about 40 degrees outside, the flight is normal:

Option #3. Do-it-yourself active refrigerator based on a Peltier element

Consumables:
1) Peltier element (rarely used for cooling computer processors)
http://www.ebay.com.au/sch/Industrial-/170769/i.html?_nkw=Peltier&_catref=1&_fln=1&_trksid=p3286.c0.m282
http://ru.wikipedia.org/wiki/Peltier_Element
2) Old ESKY box
3) A pair of radiators from computers
3) Wire and crap into the cigarette lighter.

Prelude:
One boring evening, I was gently putting computer jewelry from one place to another.
As fate would have it, Peltier elements ended up in one hand and radiators in the other. And providence had to happen, the old ESKY caught my eye.

In general, after the beer garden a crazy thought came to mind. Make a refrigerator out of computer junk.

Two radiators were taken and holes were drilled. I made a hole in ESKY for the radiator. I bolted everything together and what happened was what happened. A CPU cooler is installed outside, with inside natural convection.

Pros = 1) it works.
Cons = 2) one element is too small. 3) the cigarette lighter gets hot. 4) During operation, the element not only moves heat from the inside to the outside, but also generates heat itself. That is, (suppose) when the temperature of the internal radiator drops by two degrees, the temperature of the external radiator increases by four, five degrees.
... there was something else, I don’t remember now.

Conclusions:
The elements should be placed on the lid (easier to install, the cold will go down on its own).
You need several elements for at least some cooling.
Use either crocodile clips or T-shaped sockets. The cigarette lighter area is too small for this (which is what causes heating).
Radiators are needed much smaller in size (2/3 definitely need to be cut down), a thinner and wider monoblock should be used (and if it’s also copper...). Well, I used what I came across, my own.

All in all. It was pilot project, everything will also be finished off in the future for capacity.

Advice: It is necessary to combine the efficiency of an autothermos and Peltier elements instead of or in addition to cold accumulators.

We are not talking about a box, which a fisherman also uses as a seat in the winter, but about a refrigerator, which today can be purchased for reasonable money in almost any home, tourism and recreation store.

For me, a portable car refrigerator modified with my own hands at home (see photos 1 and 2) became a simple technical device that would brighten up the “loneliness of a fisherman” in nature and add comfort in my favorite pastime of fishing. I managed to purchase such a refrigerator for just a couple of thousand rubles, and in July I already did a crash test (wear test) modified do-it-yourself refrigerator V field conditions fishing.

How can it help in nature or fishing? Obviously, by cooling everything you want that fits into the volume of the refrigerator compartment - 30 liters; Moreover, this cooling can be carried out far from civilization and energy sources - using a portable battery.

But first, let's look at the operating principle of a car refrigerator so that it becomes clear how to modify it. The operating principle of the cooling system is based on the use of Peltier technology, which is completely safe from a chemical and electrical point of view and does not use CFCs or coolants.

What do we know about the Peltier system? The operation of the Peltier element is based on an effect discovered by the French watchmaker Jean Peltier. In 1834, during an experiment, he discovered that during a constant electric current in a circuit consisting of dissimilar conductors, heat is absorbed or released at the contact points (junctions) of the conductors, depending on the direction of the current. The amount of heat is proportional to the current passing through the contact of the conductors.

Almost the same cooling principle operates in car refrigerators and water dispensers (coolers): a supply voltage of 12-14 V is supplied to a flat Peltier element in accordance with the polarity. The cooler, just like a car refrigerator, has a solid-state a heating element flat shape, mounted on a cooling radiator with an area of 20 cm². A fan is attached to the radiator for additional cooling (see photo 3). As can be seen from photo 3, the design has a fan model RDH9025S-APF; blade diameter 12.5 cm, current consumption 0.35 A, rated voltage 12 V (operable in the range 9-24 V)

The fan and Peltier element (see photo 4) are connected by appropriate connectors to the electronic control board. The cross-section of the connecting wires to the heating element is at least 2 mm in order to minimize losses (voltage drop) in the wires from the power source. On the one hand, the Peltier element heats up (due to the applied voltage), and on the other hand, it releases cold to its surface.

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In practice, the heating element and fan can work for several hours at a time (especially in summer, when ambient temperature+25 °C or more). It is necessary to take into account both the inertia of temperature cooling and its natural approach to room temperature (despite the fact that the heat chamber is sealed, but still does not have two walls, like a good thermos), and the fact that when opening the lid, uncooled air will enter the tank, corresponding to the surrounding conditions; therefore, the overall temperature in the heat chamber will immediately increase in summer.

Inertial dependence in in this case inherent in all devices of similar model range. In table 1 shows the “cooling” characteristics of the car refrigerator I tested. Some models of car refrigerators are equipped with a built-in electronic display (inducing the temperature inside the thermal chamber) and an automatic electronic device for preserving (protecting) the battery. However, these multifunctional car refrigerators will cost much more than the one I listed (above) real price the simplest of their brethren.

Making a car refrigerator autonomous

To do this, you just need to supplement it with an appropriate battery. The power consumption of a car refrigerator is calculated by the formula (applied voltage x current consumption), 12 V x 0.35 A = 4.2 W. Based on this calculation, an AGM VRLA CT1207 battery (see photo 5) with a rated voltage of 12 V and an energy capacity of 7 A/h was selected. It's multi-purpose accumulator battery(hereinafter referred to as the battery), filled with electrolyte with the possibility of adding distilled water to the battery banks, is designed for an active service life of up to 5 years. Its weight in a ready state (filled with battery) is 1.6 kg.

The recommended battery (or its equivalent in terms of electrical characteristics) is fully charged from the car's generator (provided the engine is running) in 4-5 hours (depending on its newness and degree of discharge). That is, if you go fishing in a car, simply connect the connector of the car refrigerator to charging using wires, without turning on the fan of the car refrigerator (to make charging go better). We secure the battery in any convenient way (I secured the battery to the body of the refrigerator using a metal bracket and two self-tapping screws, but you can also use regular tape). The refrigerator is powered electrically in the “standard” way - using a car cigarette lighter socket and an adapter for 220 V.

By the way, the second option for “charging” the autonomous battery of an advanced refrigerator for fishing is preferable: from any charger at home, charge the battery separately or the battery already connected to the refrigerator, and then take it fishing. Charging time from 220 V lighting network voltage (via adapter direct current) of the same battery at home it took me 5 hours.

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The undoubted advantages of a modified refrigerator for fishing

Considering the low price refrigerator and its simple modification (so that it serves the fisherman in offline mode), today there is no reasonable alternative to such a device. After all, even after turning off the power to the refrigerator compartment, its contents will remain frozen (remain cold) for a long time (according to my tests, if you do not open the lid, the accumulated negative temperature down to 0 ° C can remain for 12 hours or more).

What can you store? Bait, fish, crayfish (including live ones - to do this, fill the thermal chamber with water within reasonable limits), medicines, snow, ice and much more. The rotation noise of the refrigerator fan is low, which is also confirmed by a special test. I carried out the “noise test” using a special professional sound level meter DVM401, which showed a level of 71.2 dB when the microphone sensors directly approached the operating refrigerator fan (see photo 6). For comparison: the fan of my laptop makes approximately the same sound if this noise is recorded with the same device in the immediate vicinity of the noise source. Thus, for fishing and tourism this device can be considered quite acceptable.

Conditions for long-term operation of a fishing refrigerator

To fishing refrigerator served for a long time and with high quality, it will be necessary, if possible, to fulfill several simple conditions. Connection to the device must be made in compliance with polarity (+ and -). So the car refrigerator will serve the fisherman for an unlimited number of years. In order to preserve the cold in the thermal chamber even more, I recommend putting 2-3 sealed isothermal cold accumulators inside (flat flasks measuring 10x20 cm, with filler from any manufacturer), you can purchase them in the same stores for a symbolic price of 150-200 rubles.

Recommendations for using a refrigerator for fishermen

Clean after each use (storage of fish or bait). damp cloth the insides of the heat chamber and the outer walls. Since the device accumulates cold relative inert, at an external ambient temperature of 20 °C, inside the heat chamber the temperature of +3 °C will be reached only after 35 minutes of operation; to maintain the cold inside the chamber, the lid of the refrigerator should be opened as little as possible during operation.

Additionally, you can carry out an event to maintain the temperature in the heat chamber. To do this, the lid of the car refrigerator will have to be opened to step illustrated in photo 3. And along the perimeter of the inner lid, self-adhesive insulating sealing tape, used for sound insulation in car repair shops (to reduce the noise and vibration of contacting plastic parts). This tape is freely sold in auto supply and/or home improvement stores. How to do this correctly is shown in photo 7. After laying the tape around the perimeter, the lid is assembled in the reverse order, tightening 6 screws until they stop. Now your new thermal saver is ready for fishing and outdoor recreation.

Cautions

There is a limitation based on electrical characteristics built-in fan - active continuous operation for no more than 36 hours. However, this time is quite enough for a trip to nature. For those cases when outdoor living conditions and operation require more time, it is enough to turn off the car refrigerator for 2 hours and then turn it on again for another 36 hours. It is not advisable to keep the refrigerator box near an open fire, so as not to damage the integrity (deform) of the sealed chamber.

You should also not completely immerse the refrigerator in water, since it contains electrical parts and components (fan, cooler with Peltier elements, battery), so as not to damage the refrigerator and harm the environment. Covering (either unwittingly or intentionally) the ventilation grille will cause the cooling efficiency to be greatly reduced. For the same purpose, it is not advisable to operate the refrigerator in the desert, on the beach or in places with a lot of dust. On the other hand, practical tests have shown that modified car refrigerator serves well both in summer and winter and can keep not only frozen fish for you for several hours, but even ice and snow (see photos 8 and 9).

Do-it-yourself refrigerator for a car (3 options, photos, step by step)

Option #1. Do-it-yourself passive thermos

I don’t know if I chose the right section, but I decided that this topic would be appropriate here. I invite everyone to share their HOME MADE experience here...

This year we will definitely go to the sea. It is better to keep the “brake” and drinks in the cold to prevent them from spoiling. And for this you need a refrigerator. Buy a car refrigerator from a cigarette lighter for 4,500 rubles. “toad” doesn’t give me any. Therefore, for the old car, it was decided to make a new, major refrigerator with “cold accumulators” in the form of frozen one and a half cups of water. The old refrigerator made of packaging cardboard lasted 3 trips to the south, and was mercilessly thrown into the trash (I attached a photo below (not the trash, but the refrigerator)).

I decided to insulate, or rather thermally insulate, using foam insulation with foil on one side, 10 mm thick. Width 1.2 m, length 1 m. Price today is 90 rubles/1 m.

The body material was waste from our furniture production - MDF (or, to be clearer, fiberboard) 10 mm thick. Purchased 2 aluminum corners 15*15 mm for 120 rubles. for both. Also purchased were rivets 4*16 (100 pieces - 50 rubles) and 2 furniture bar hinges for 30 rubles each. each. That's all the expenses - 295 rubles. Tools and equipment were borrowed from work (where the refrigerator was assembled).

Cutting off the corners in place, we slowly begin to assemble the box of the future refrigerator.

As a result of the “titanic” labors we got this nice little box.

As a result, after 3 days of working in my free time from my main job (of which there is not so much), I got this nice refrigerator with a hinged top lid with a latch.

4 one and a half liter bottles of water, or 6-8 half liter bottles, previously frozen in the freezer, will be fixed or placed in the corners or on the bottom. You can use mineral water, cold, and with gas, in the heat it’s so invigorating. It is better to take half-liter mineral water, this volume is the most practical. Bottles are not filled with water full, otherwise, when the water freezes, the ice will expand and tear the bottle, and the food will float in the thawed water. To save space in the refrigerator, you can buy a branded “cold accumulator” in the store - these are special bags or flat boxes with liquid inside, which are used instead of bottles (one large one costs about 120-150 rubles). Only bottles with spring water are free! And even when the water in them begins to melt (and this happens in about a day), it can be used for cold washing or drinking.

Option #2. Do-it-yourself passive thermos

I’ll say right away that this thermos auto-refrigerator was invented by my friend Valera!! For which we are very grateful to him. He lives in the south, it’s hot here, so there’s a catastrophic shortage of car refrigerators for food on vacation, especially if we go with a large group. Valera made such a thermos auto-refrigerator with her own hands several years ago, so she decided to do something similar.

Total, having bought a box for children's toys - 350 rubles, 2 sheets of polystyrene foam 2x50 rubles = 100, 2 two rolls of metallized tape 2x100 + 200, universal glue 80 rubles, mounting foam 120 rubles TOTAL 850 rubles and 2.5 hours of my precious time.

Two days later, compote from a thermos on the Dolzhanskaya Spit, about 40 degrees outside, the flight is normal:

Option #3. Do-it-yourself active refrigerator based on a Peltier element

In general, after the beer garden a crazy thought came to mind. Make a refrigerator out of computer junk.

All in all. This was a pilot project, everything will also be completed in the future for the capacity.

Advice: It is necessary to combine the efficiency of an autothermos and Peltier elements instead of or in addition to cold accumulators.

In order to make a car refrigerator with your own hands, there is no need to purchase expensive materials and come up with complex assembly schemes. In this article we will look at a simple and effective method make a car refrigerator minimum costs time and money.

1 Homemade refrigerator - assembling the body

The body of the future refrigerator can be assembled from various materials, however it is best to use construction material, namely extruded polystyrene foam. This material has many advantages and is inexpensive. Expanded polystyrene is actively used for insulation various designs and buildings, it has excellent thermal insulation properties and resistance to external influences.

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To model the body of the future refrigerator, you will need one or two sheets of polystyrene foam standard sizes and width (1200x600 and 50 mm), the cost of one sheet in a hardware store does not exceed 450 rubles. To glue the container, you will also need several cylinders of polyurethane foam. To work, you will also need a tape measure for measurements and a stationery knife, with which you need to cut a sheet of polystyrene foam according to a pre-prepared template.

It is best to make the walls of the container double by gluing the sheets together polyurethane foam. To do this, apply a little foam to the surface, connect the sheets and wait 5-10 minutes until completely dry, making sure that the sheets do not move due to the expansion of the foam. The size template can be taken as usual wooden box, only in our case, instead of wood, insulation material is used.

Double wall container

Once the container is created, the outside can be painted any color using regular paint. It is better to paint in several stages, as the paint eats up the polystyrene a little. As for the lid, it is necessary to cut a piece of material so that it fits as tightly as possible to the surface and closes tightly. Even without electrical elements, such a box is capable of preserving very frozen foods for several hours, since the material has low performance heat loss

To obtain full refrigerator, it is necessary to connect a Peltier element to the housing. The operating principle of a thermoelectric conversion device is based on the occurrence of a temperature difference depending on the flow of electric current. This device is also used for industrial production car refrigerators, and you can buy it at a hardware store.

2 Connection of electrical elements

To make a full homemade refrigerator, and not just a thermal container, in addition to the Peltier element, you also need to purchase a computer cooler (in any specialized store). A cooler is necessary to actively remove heat from one of the parts of the refrigerator, since during operation one side will heat up and the other will cool, due to this a certain temperature will be maintained inside the box. To control this temperature, you also need a thermostat with a special sensor, and to connect the refrigerator to the car's on-board network, you need an extension cord with a cigarette lighter connector.

Computer cooler First you need to install a Peltier element between two aluminum radiators. At this stage, you can use thermal paste for the cooler, and lay a small piece around the perimeter between the element and the radiators thermal insulation material(pipe insulation is suitable). Radiators can be connected by mounting plates to motherboard, and the plates - with plastic clamps.

Installing a Peltier element in a homemade car refrigerator Thus, the more intensively the hot side of the container is cooled, the lower the temperature on the cold side will be. With one Peltier element and a cooler at correct installation You can achieve a temperature of minus 2 degrees inside the box. To lower the temperature inside, you can use several Peltier elements, so that one cools the other, etc.

3 Installation of the structure in the lid of a homemade refrigerator

If the structure is assembled correctly and during a test run it is pumped desired temperature, you should start installing a cooler with a Peltier element in the lid. For better heat dissipation, it is recommended to double the thickness of the lid, that is, place another piece of polystyrene foam on the foam to fit the size of the lid. You should cut a hole in the insulation to fit the size of the structure (use a utility knife), then use sandpaper to level the surface and, if desired, paint it again. In this case, paint allows not only to improve the aesthetic appearance, but also gives strength to the outer shell of polystyrene foam.

Cooler with Peltier elementNext you need to install the fans and coat the seams with sealant. The fan speed can be adjusted, but it is best to leave the maximum blow speed to ensure the lowest possible temperature. You need to connect a thermostat sensor to the fan, and secure the board itself to the cover using self-tapping screws. The power cord to the cigarette lighter is also installed in the cover; you can use a plate and self-tapping screws, and seal the plate body with sealant.

Thus, at the end you will get a high-quality homemade refrigerator. The weight of the box will be approximately 800–900 grams, and the lid with an integrated fan and thermostat will weigh the same.

When using such a refrigerator in summer weather, provided that the fan is always blowing maximum speed, the temperature at the bottom will remain stable at +5 ... +7 degrees. In this case, the entire structure will consume no more than 4 amperes of current.

For a more powerful result, as we have already noted, it is necessary to integrate two or three in series installed elements Peltier, but this will be a freezer, and not a simple refrigerator. And to create such temperatures it will be necessary to use an additional radiator and antifreeze, according to the principle car air conditioner, and this is much more difficult to do. There are several more ways to make a car refrigerator with your own hands, but the presented method is the most effective and simple, in addition, the cost of all parts does not exceed 3,500 rubles, and the result is quite enough for transporting various products over long distances.

In refrigeration units, cold is produced only in two ways - freon and electrical elements Peltier ( thermoelectric converter). The first option is suitable for large units, such as two-door appliances. The second is for homemade small chests. Despite the comparative simplicity of the device and its prevalence, refrigerators remain an expensive device. That's why the topic self-assembly small freezers using Peltier elements is relevant and important.

The best materials for a homemade refrigerator

If you have the knowledge and all the necessary spare parts, making a functional homemade refrigerator is quite easy.

You should start by assembling the body of the future device. A variety of materials are used to produce chests:

pieces of laminate - thanks to the presence of special grooves, the structure is easy to assemble and is durable;
Styrofoam - brittle material, easy to process, not afraid of moisture;
MDF or fiberboard - without special processing afraid of moisture;
penoplex or technoplex is used for insulation external walls buildings;
plastic box with a lid (tool box).

In general, anyone who has something lying around in the garage or on the balcony will do just fine, the main thing is to insulate the box inside and out.

Experience shows that best option for a homemade refrigerator - extruded polystyrene foam.

Among its advantages are:

low level of thermal conductivity - only 0.031 W/(m °K);
relatively high strength (than denser material, the stronger);
resistance to moisture;
little weight.

In addition, the material is easy to process, and parts made from it are perfectly glued together using ordinary liquid nails.

How to make a homemade refrigerator box

The finished box already retains cold perfectly, but in order for it to produce it, the box must be supplemented with a cold converter and the elements necessary for its operation.

Installation of the cooling unit, calculation of the power of Peltier elements

The next step is the assembly and installation of the cooling unit of the future refrigerator. To get fully functioning equipment, you need to connect the case to a Peltier element, which can be purchased at any radio equipment and computer parts store.

The operating principle of a Peltier thermoelectric converter is the temperature difference between their upper and lower parts. When a 12V battery is supplied, the current that passes through the part is converted into thermal radiation (top side) and cold flow (bottom side).

The advantages of the Peltier element are the absence of moving parts, gas or liquid. In addition, their work is not accompanied by noise. The part is used both in mini-refrigerators and in drinking water coolers.

The main disadvantage of the element is its relatively high cost.

The lower edge of the Peltier element becomes the source of cold for the homemade refrigerator. The main technological task at this stage is to transfer cold to inner part refrigerator, where the radiator is installed and, conversely, heat energy is removed outside. From the point of view of physical processes, the following design is effective:

An aluminum beam is mounted into the side wall of the refrigerator at a right angle. Metal surface will ensure the supply of cold inside the housing.
On the chamber side, a radiator is connected to the beam, which distributes the cold.
WITH outside To aluminum part a Peltier element is attached, which releases thermal energy.

You can take the easier route and place the cooler on adhesive-sealant, but this is less effective.

How to calculate a refrigerator operating on Peltier elements

In order for a homemade refrigerator to fully perform the functions assigned to it, the correct calculations must be made.

Please note that the heat loss of a refrigerator depends on the temperature difference between inside and outside the appliance. For example, the temperature of the room where the chest is located is 25 degrees. Accordingly, if a cooling element is not installed on the refrigerator, it will be the same 25 degrees inside. If you add one Peltier element with radiators on the sides and reinforce it with a cooler, then after some time the temperature in a sealed compartment of 30 liters will drop to 19 degrees. What it looks like on paper:

Draw two axes on a piece of paper. At the point of their intersection, put the number 0. In this case, the horizontal line is the temperature, and the vertical line is the power of one Peltier element, which balances heat loss.
for clarity, place a dot on the horizontal line that will indicate the temperature without the element equal to 25 degrees;
from this point, begin to draw a straight line towards the vertical axis;
on section 2/3, place a dot that will indicate the temperature of 19 degrees;
if you mark another 1/3 of the segment, the temperature will decrease to 13 degrees and for this indicator you will need two elements. Each subsequent part lowers the temperature by 6 degrees.

To cool the air in a small home refrigerator, you will need three Peltier elements. Suitable for providing energy to the device. In addition, it can be powered by a car battery (you will need an extension cord with a cigarette lighter connector).

In order for your refrigerator to generate cold, it is important to adhere to a number of rules and recommendations when installing a Peltier element.

Observe the polarity of the wires. If you do not do this and change the polarity, then when the element operates, the opposite parts of the part will heat up and cool down.
Provide constant air cooling to the top part of the element, which heats up. For this purpose, both a specially purchased cooler and a fan from the system unit are suitable. The power of the Peltier element largely depends on the strength of the air flow.
An important detail in uninterrupted efficient work The cooler is an insulating gasket. It removes heat from the upper side of the element so that the lower cooling radiator can uninterruptedly perform its task.
It is recommended to fasten the working element between the upper and lower radiators like a “sandwich”. First comes the top radiator. Next, a small layer of thermally conductive paste is applied using a syringe. This substance sticks to ceramic surface Peltier element. On bottom part The parts are again coated with heat-conducting cream, onto which the lower cooling radiator is attached. To connect all the components, they should be pressed firmly and the structure should be allowed to dry for five hours.

Additionally, another one can be attached to the lower radiator. This will allow the device to better distribute cold throughout the area of the chest. The refrigerator will also reach the required temperature faster. The cooler eliminates the formation of condensation on the walls of the device, so that the products placed in it will always be dry.

The process of reaching the temperature required to cool food depends on how warm it is in the place where the refrigerator is located. The warmer it is outside, the longer it takes to cool down. An important aspect is the heat-insulating qualities of the refrigerator itself and its volume. A good homemade refrigerator should be airtight and have a tight-fitting lid.

To summarize, we can conclude that for self-creation A small refrigerator that will freeze and keep cold will need three Peltier elements and two coolers for a cooling and heating radiator. The body will be a box pre-coated with insulation or a hand-assembled structure made of polystyrene foam, polystyrene foam or any other material. If you have all the listed items, minimal skills in working with equipment, time and desire, anyone can repeat the experience of assembling a refrigerator on their own.

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