How to make a car refrigerator with your own hands?

Do you urgently need a car refrigerator, but are you currently short of money or are you under pressure? Assemble a car refrigerator with your own hands and enjoy the comfort.

Imagine you and your friends are going fishing, hunting, or just out of town. A trip with a large group requires a considerable supply of provisions that you need to take with you. And the question immediately arises - how to maintain a supply of food and drinks for a long time. Only a car refrigerator can help you. By purchasing this modern unit, you will immediately solve all your food storage problems. In addition, on the way back you can put caught fish or small game in it. I began to decide what was better - to design a car refrigerator with my own hands or buy it in a store. If you have extra money and no free time, choose the second option. A refrigerator designed by yourself will cost a ruble, but will bring a lot of benefits.

DIY car refrigerator assembly

All the materials we need can be purchased at the nearest building materials store.

Thermal insulation material (foam plastic, penoizol, expanded polystyrene);
A roll of thick foil;
Plywood box.

The size depends on what you want to get - a refrigeration unit that fits the entire trunk or a small refrigerator that can be installed on a seat in the car.

Then everything is very simple. Take a box and line it with heat insulator from the inside. This must be done carefully, without leaving any cracks or gaps. Through them all the cold will go out. The lid of the box is also treated with foam plastic and fits well to the body. For better thermal insulation, you can treat the outside of the box. Then insulate the entire structure, inside and out, with foil. In this simple way you can make a basic refrigerator. By placing cold “cold accumulators” (plastic water bottles) inside, you can keep the stored food fresh for 24 hours. This box is very convenient for a short trip. If you are going on a long trip, you will need to make a car refrigerator of larger volume and power.

Watch the video below on how to make a car refrigerator with your own hands.

1st method. Do-it-yourself passive auto thermos

To create such a solution, we select refrigerator dimensions in the area of 40x40x30 cm, which, however, can be varied depending on the dimensions of the car trunk. For average cars, this size is better, since a refrigerator that is too large would take up a lot of space, and there would be no place to put things.

Insulation, namely thermal insulation using foam insulation with foil on one side, should have a thickness of ten millimeters. Width 1.2 meter, length 1 meter. The price tag is currently 90 rubles per meter. The body materials used are furniture waste, or, to be more precise, ten-millimeter fiberboard. Buy two aluminum corners 1.5×1.5 mm for 120 rubles. Blind rivets of the 4×16 type are purchased “one hundred pieces for 50 rubles” and a pair of furniture hinges for 30 rubles each. Total expenses can be about 300 rubles.

DIY car refrigerator from the cigarette lighter

The body of a car refrigerator powered by a cigarette lighter is no different from the body of a refrigerator box. The same plywood box, polystyrene foam and foil. Only your own cooling element is added. Its role will be played by Peltier elements and a small fan (can be taken from a computer). The higher the cooling temperature is needed, the more Peltier elements will have to be installed. By connecting your creation to the cigarette lighter, you will get a full-fledged car refrigerator that will help you out on vacation and fishing.

Read how to choose a gas car refrigerator.
And also about how to choose a car refrigerator.

DIY compressor refrigerator

If you need a more serious unit with faster and more reliable freezing, it is better to make a compressor auto-refrigerator. It is quite difficult to assemble it, but, in principle, it is possible. You will need a compressor, condenser and evaporator, all of which can be purchased at the store. With some electrical knowledge, it is quite possible to install these items in the refrigerator box and your compressor refrigerator is ready

A self-made car refrigerator has considerable advantages:

The most important advantage is the price;
With some skills, you can make almost any car refrigerator with your own hands;
Will preserve food supplies no worse than a purchased unit;
If necessary, a self-made car refrigerator can always be improved;

Published: November 15, 2021

2nd method. Passive car thermos

To create another option, you need to buy a box for children's toys for three hundred and fifty rubles. You should also choose a couple of sheets of polystyrene foam for a total of one hundred rubles, a couple of rolls of metallized adhesive tape, universal glue for eighty, you will also have to resort to mounting foam for 120 rubles. All the necessary material is unlikely to exceed the amount of 900 rubles.

The entire work will take two and a half hours of your time.

2 Connection of electrical elements

To make a full-fledged 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 of thermal insulation material around the perimeter between the element and the radiators (pipe insulation is suitable). Radiators can be connected with plates that are attached to the motherboard, and the plates can be connected with plastic clamps.

Installing a Peltier element in a homemade car refrigerator

Thus, the more intensely 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, if installed correctly, 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.

Advantages and disadvantages of thermoelectric cooling devices

Thermoelectric cooling air conditioner based on the Peltier effect has the following advantages:

High specific cooling power. With dimensions of 40x40x3.8 mm, one element can remove thermal energy with a power of up to 57 W.
Quiet operation.
Low cost. One element costs no more than $3.
High reliability. The time of continuous operation before failure reaches 200 thousand hours.

Disadvantages of Peltier coolers:

Low efficiency. Therefore, with a large cooled volume, it is difficult to achieve a significant temperature difference between opposite surfaces.
The air conditioner consumes relatively more power. The current consumed by one element reaches 6 A.
Part of the power consumption is spent on heating the radiator, which releases heat to the atmosphere.

A self-made refrigerator, of course, will not notice air conditioning or climate control, but in any case it will make traveling in hot weather easier.

Compressor

This is a thermally insulated metal freezer equipped with a compressor and evaporator. The operating principle is similar to that of a traditional home unit. The liquid refrigerant becomes a gas in the evaporator and takes away heat. Using a compressor, the substance is removed, condensed, and becomes a liquid again under pressure.

Advantages of assembling a compressor auto-refrigerator with your own hands:

saving. Industrial analogues of equipment are expensive;
cooling products to 18°C degrees below zero;
rapid achievement of the desired cold characteristics inside the chamber;
efficiency;
capacity;
versatility.

Drivers often refuse to manufacture cooling equipment that works on this principle, but choosing a type based on price is a mistake. If you just need to have a cool bottle of water nearby, you can settle for inexpensive options. When you need to transport quickly perishable food, baby food, or have a long journey ahead, it is better to use a compressor.

A comparative analysis of the types of car refrigerators allows us to conclude that compressor devices are the best option. Although they are more expensive than thermoelectric ones. This is compensated by operational efficiency, cost-effectiveness and the ability to freeze food, regardless of the heat outside. Absorption systems cost the same as compressor systems. However, they are inferior in the degree of cooling.

Comments:

Which car refrigerator is better to choose?

If preference is given to purchasing a ready-made car refrigerator, then after determining the main purchase criteria (volume, duration of trips, free space inside the car) and choosing the type of refrigerator, they usually study customer reviews about the experience associated with the sale and operation of goods with similar parameters.

The most famous manufacturers of car refrigerators are:

WAECO is a German company founded more than 30 years ago. It enjoys well-deserved authority both for the high quality of its products and a wide range of auto-refrigerators of various types, as well as a fair price level in terms of quality. Acquired by DOMETIC in 2007 and sometimes produces products with a double name: Waeco Dometic.
DOMETIC is the world leader in mobile refrigeration equipment (rebranding of the famous Electrolux). The products of this company have only one drawback - the high price.
Ezetil is another German brand that produces high-quality products at an affordable price (with the exception of absorption-type refrigerators).
Camping World is a Russian brand that produces refrigerators made of safe food-grade plastic. The low cost of goods is achieved through the use of Chinese components and Chinese assembly. The latter is rather a disadvantage of refrigerators.

And finally, we suggest watching a video with reviews of the most popular models of car refrigerators on the domestic market.

Airbrush

Let's start with the most difficult one. For this type, a special airbrush tool is used, and the artist also uses brushes for detailed drawing of small details. If you have talent and experience, and also have the necessary tools and special paint, you can create this design yourself. However, it is better to entrust the matter to a professional. The procedure is expensive, but you will get a real work of art that fits perfectly into the overall design of the room.

Before applying the design to the surface, it is modeled using computer graphics. Your help will be needed here. To avoid disagreements regarding small details, location and colors, it is better to create a layout of the future image together with the master.

Landscape stickers look very beautiful

You can put these fun stickers on your refrigerator:

See alsoStudio kitchen design: what to pay attention to?

On Peltier elements

Refers to thermoelectric type of equipment. The Peltier element, which forms the basis of the cooling system, uses the principle of the temperature difference between the upper (heated) and lower (cooled) parts. The device transfers heat from the chamber to the outside. The efficiency of the equipment depends on the air temperature around, the effectiveness of the thermal insulation of the housing, and the volume of the chamber.

Making a car refrigerator with your own hands using Peltier elements is justified by saving money and the versatility of the equipment. It can be connected to a standard 12V car system, 220V AC network. The first option does not require the installation of additional power supplies or fans, and will cost much less.

Advantages of a Peltier refrigerator:

small size and weight;
ease of use;
durability;
economical operation;
constant maintenance of temperature.

Minuses:

air cooling 10-15 degrees below ambient temperature;
it takes more than one hour to achieve the specified cooling parameters.

Cooling without compressor

The Peltier effect is that when an electric current flows through the contact of two semiconductors with different types of conductivity (pn junction), depending on the direction of the current, it either cools or heats up. This is explained by the interaction of electrons with thermal vibrations of the atoms of the crystal lattice. And when current passes through series-connected junctions, the thermal energy absorbed by one pn junction is released on the other.

If you arrange the Peltier element so that one pn junction is inside a container with good thermal insulation, and the other outside, you will get a small refrigerator that is sufficiently powered from a car cigarette lighter. Another refrigerator that operates without a compressor is absorption. You can make a refrigerator for your car from such an old unit. But in this case, the design will depend on what you got, so you will definitely need to change the heaters and thermostats to 12 volt ones.

Making the body

To make the case you will need materials:

MDF 10 mm thick.
Aluminum corner 1.5×1.5 cm.
Blind rivets 3×15 mm.
Furniture hinges – 2 pcs.
Frog type latch lock.
Foamed foil thermal insulation 10 mm thick.
Oilcloth on a fabric basis.
Glue "liquid nails".
PVA glue.
Sealant.
Foam seal for windows.

One Peltier element will not be able to significantly cool a large volume, so for one thermoelectric element do not make the housing larger than 40x40x30 cm.

To cut hardboard, use an electric jigsaw or circular saw; if you don’t have them in your arsenal, a regular hacksaw with a fine tooth will do. From MDF sheets, using corners and blind rivets, assemble a box that will be the body of your mini-fridge. Place the corners from the inside so that the rivets are held more securely. Fill all cavities in the joints between structural parts with sealant. After the sealant has dried, cover the inside surface of the resulting box with insulation. Use “liquid nails” for this.

Apply foam rubber seal to the upper ends of the walls. MDF is very hygroscopic, so it must be primed before gluing the body. Instead of a primer, dilute a little PVA with water (add 2 parts liquid to 1 part glue). Prime the body, let it dry and cover it with oilcloth. Do not tape the door, as it is a radiator, and tape will worsen its heat transfer.

Cooler installation

For this you will need:

Peltier element.
Electric fan with operating voltage 12 V and mount for it.
4 screws M 3×15 with nuts.
Connector for connecting to the cigarette lighter socket.
Two copper, stranded, insulated wires. Determine the cross section based on the total power of the Peltier element and the fan.
Thermal paste.
Sheet aluminum 3–4 mm thick.

First you need to make two radiators from aluminum, mount a cooling element between them and separate them from each other with a sheet of thermal insulation. This design will double as the refrigerator door. With the outer dimensions of the case being 40x40x30 cm, the top radiator should be 40x40 cm, since it will cover the box, and the bottom one should be 38x38 cm, because it should go inside. Cut a 38x38 cm square from a sheet of insulation, cut a hole in its center the size of the cooling element and glue it to the smaller radiator using “liquid nails”. Solder the power wires to the terminals of the element (the red terminal should be “+”, and the black terminal should be “ground”).

Place the large radiator down, and the small one on top of it, with the insulation facing up, so that their centers coincide. A centimeter from each corner of the cutout in the thermal insulation, drill a Ø 3 mm hole simultaneously in two radiators. Lubricate the cooling element on both sides with heat-conducting paste and place it on an area of the smaller radiator free of insulation with the cooling side facing the metal. Cover it with a large radiator so that the previously made holes coincide, and tighten the resulting sandwich with screws and nuts until the thermal insulation is compressed and the radiators touch the cooler. Monitor compression using a caliper by measuring the distance between the radiators. The thickness of the element is 3.8 mm. After reducing the gap to this value, tightening the radiator plates should be stopped.

Attach the resulting door to the hinges, and them to the body so that when it closes, the smaller radiator fits inside the body. To remove the wires from the housing, place a piece of rubber tube of suitable diameter on them. In the top plate, next to the cooler power connection contacts, drill a hole slightly smaller than the outer diameter of the tube. Route the wires through it, leaving the tube in the hole so that the wire does not rub against its edges. Attach the fan to the door so that it points towards it and connect it to the same pair of wires. All that remains is to attach a latch and some kind of handle for carrying the device and the cold generator is ready.

Selecting wire cross-section

To find out the current consumed by the built air conditioner, add the rated current of the fan with the same parameter of the cooling element. After this, all that remains is to select from the directory the wire cross-section corresponding to this current. We provide below a fragment of the reference book sufficient to make a decision in this case. For connection lengths up to 2 m:

current up to 1.5 A, wire cross-section – 0.3 mm2;
current – 2.5 A, cross-section – 0.5 mm2;
current – 3.5 A, wire – 0.7 squares;
current - 7.5 A, wire 1.5 square;
current – 10 A, wire – 2 mm2.

With a connection length of 3 m:

Inom up to 1.5 A, wire – 0.4 mm2;
Inom – 2.5 A, wire – 0.8 mm2;
Inom – 3.5 A, wire – 1.1 square;
Inom – 7.5 A, cross-section – 2.3 mm2;
Inom – 10 A, cross-section – 3.2 square.

If your air conditioner draws more current than the cigarette lighter fuse is designed for, you will have to connect it to the battery terminals through its own fuse link. But you will save on the connector for connecting to the cigarette lighter socket.

The cross-section of a single-core wire S after measuring its diameter d can be calculated using the formula – S=π*(d/2)2. To determine the cross-section of a stranded wire, you need to count the number of veins under the insulation, calculate the cross-section of one and multiply by their number.

If you don't have a caliper, you can determine the diameter of a single-core wire using a regular ruler. To do this, wind 10 turns of wire around a screwdriver, turn to turn, and measure the length of the resulting winding with a ruler. Divide the result by 10 to get the wire diameter.

Power Requirements

The device must be powered by a direct current voltage of no more than 15 V. Small ripples do not interfere with operation. This means that a homemade air conditioner does not need special conditions and can simply be connected to the on-board network of a car with 12 volt electrical equipment. For owners of cars with a 24 V on-board voltage, it is recommended to connect two cooling elements in series.

Film

Another alternative to painting and stickers is decorative film. It will be even easier with her. There is no need to create a combination of stickers and figure out how to place them. It is enough to purchase a film of the appropriate size and cover the refrigerator with it, placing it over the entire area.

There are also many options for vinyl wrap. You can choose an existing plot, purchase a plain film, or with some kind of pattern. You also have the opportunity to order large-format printing on film, applying your favorite pattern or your own photographs to it.

There is also a practical side to the option of completely covering the refrigerator with film. This coating is dense and will protect the surface from scratches. Periodically, you can change the film or remove it completely, and your refrigerator will have a new look without scratches or chips.

You can put special stickers on the doors

You can decorate your refrigerator with magite

You can put special stickers on the refrigerator door

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