During the struggle for environmental friendliness and decent existence, attention is drawn to the smallest details. Tired of the constant noise of the cooler in the processor - remember, the device requires cooling, otherwise the BIOS will simply cut down the system unit along with the operating system. And in the heat you want peace and quiet. Solution found. Previously it was said that refrigerators are not only alive by compressors, alternative models have been created. We will think that it will be possible to assemble the refrigerator with our own hands.
The history of refrigerators, or the Handbook for the inventor of
, was mentioned in reviews about adsorption refrigerators running on blue fuel. Gas, burning, causes the refrigerant to circulate and cool the compartments. The undoubted advantage of the design is noiseless. Able to hear a slight hiss from burning fuel, the flow of fluid through the tubes. But the solution is not the only one. They wrote that expensive car refrigerators work on a different principle - on Peltier elements.
In 1834, it was found that by passing a direct current through conductors and semiconductors, heat is released or absorbed. The effect was not attributed to the Joule-Lenz law: in the latter case, the heat was released, but the cooling remained unattainable. Nobody gave a scientific explanation, but it became known that when current is passed in one direction, heat is absorbed, in the other it is released!
There is a known case when a student reported to a teacher on the subject of digital technology, computers have not yet gained today's strength. Processors Pentium II just appeared on the Russian market, although in the US, of course, there are already fourths. It was a matter of feeding the brain of a computer, the desire to constantly lower the voltage.
Noticed that the processor consumes 75 watts. At the same time, the supply voltage remained in the region of 3 V. It turns out that a small crystal consumed a current. .. 25 A. Any battery when charging is not capable of such. The teacher spoke, but was not quite right.
At a specified low voltage, the processor actually consumes a giant current, some of the power goes to useful needs, and heat inevitably releases to the environment. And tangible! Without a cooler, the processor can reach the boiling point, it would warm up further, but the protection systems will turn off the power earlier. It turns out, the processor spends considerable power. Recently, Peltier elements have appeared on the market to cool the raging brain. A user noticed that the processor was cooled. .. to minus 10 degrees Celsius. Impressive?
Peltier elements can not be called cheap. How on their basis to build a homemade refrigerator: put parallel to the inside of the insulated tank, where the temperature will begin to gradually fall. But the freezing capacity of refrigerators is not measured in watts, it is calculated by the number( in kilograms) of products, the temperature of which can be reduced to a predetermined one. We do not know what is meant by the statement that the power of the Peltier element is 77 W.At a price of 300 rubles per piece, it is worth trying to calculate the cost of a home-made refrigerator, correlating these parameters. We offer a different way.
Remember, in reviews we gave a method for determining the required heating power of a room, and now we use it in reverse order. Experiment Steps:
- An ordinary thermometer will be needed. Better simple street. Thermometer put in our homemade fridge.
- Making the case. In these refrigerators polyurethane foam is used for thermal insulation. Buy spray can in the building materials store. Polyfoam will also fit, we recommend to apply insulation of reflective type Penofol or similar. For example, a box is taken, from both sides it is tightly finished with the above-mentioned material, in fact, a good homemade refrigerator is already ready. For information - the material is taken from the space industry, where it was used to create space suits. The sun's rays are deadly outside the atmosphere, and the cosmic cold will make Sauron shudder, but the cosmonaut did not cause any particular damage under the Penofol layer. Of course, gold and silver were used in spacesuits, but not aluminum, possibly without polyethylene. The fact is that the characteristics of the material are amazing.
- The cooler will first become a single Peltier element. We mount it on glue-sealant. Then we will show a technique that allows you to find the number of modules needed for the home-made refrigerator to start freezing.
The method of calculating the home-made refrigerator on the Peltier elements
We proceed from the fact that heat losses depend linearly on the temperature difference inside and outside the home-made refrigerator. We go from simple to complex:
- Suppose the temperature in the room is 20 ºС and remains unchanged throughout the experiment. Let's start the study. Obviously, in the absence of Peltier elements, the temperature inside the refrigerator will be 20 ºС.This is the first point on the line( losses grow linearly due to the temperature difference outside and inside the improvised refrigerator).Install the Peltier element with radiators on both sides, and the outer one will be blown with a cooler to enhance the effect.
- Over time, the temperature in the 30 liter compartment was 14 ºС.We affirm that by adding two more Peltier elements with radiators and coolers, anyone will get 2 degrees of heat inside a home-made refrigerator if the room has 20 ºС heat. Scheme:
- Draw two axes on a sheet of paper. At the intersection point on both - zero. Horizontal - temperature line.
- Mark a point on the horizontal of 20 ºС.This is the initial moment when zero power is wasted, and the temperature inside the improvised refrigerator is equal to room temperature.
- Now draw from a drawn point a straight line intersecting the vertical axis at any, but always positive, height.
- Mark two thirds of the origin of a point on the X axis( temperature).This is 14 ºС, and the vertical on the line is the power of one Peltier element, which has balanced losses.
- Now mark the point at a third from the beginning. Here it is 8 ºС, and Peltier elements will need two already. This is visible on the schedule.
Conclusions on the self-made refrigerator
constructionsExperience is permissible to generalize, select the optimal isolation, vary the conditions. For example, remove the coolers, so as not to make any noise or waste energy. This will simplify the design. But we want to cool the ardor of inventors: in real, not improvised refrigerators, two fans are used for the cold and hot circuits. Experiment.
The refrigerator device will sustain the computer power supply. Remember how much the processor consumes! Peltier element is not the main thing inside. The voltage has already been adapted in advance, it is not necessary to look for rare details. You buy three Peltier elements to make a refrigerator yourself, take a power supply unit from an old PC, build a box with two coolers, get the finished product. And able to work on the car battery.
The principle of operation of the refrigerator is so obvious that it is understandable to children. When changing the direction of the current, the Peltier elements work on heating. It is good to have warm food nearby when there is no heater around. In the latter case, the law works in the opposite direction. Three Peltier elements inside a home-made refrigerator will provide a temperature 18 ° C above the environment. If the car is 25, it will show 43 in the box. Enough to eat and not complain. It turns out already two devices in one person.
We want to say thanks to the author of the video on YouTube for the great idea how to make a fridge yourself. Let the idea is not too successful, but only because the volume is large. The Peltier elements of the processor are not so powerful that alone can overcome a large amount, which is not fully decorated.
