Ecology of consumption Science and technology: Imagine a solar collector made of plastic bottles. It can help disadvantaged communities find a reliable source of energy and, at the same time, a waste recycling system.

Imagine a solar collector made from plastic bottles. It can help disadvantaged communities find a reliable source of energy and, at the same time, a waste recycling system.

Such a project was implemented in Garina, a town 40 kilometers north of the Argentine capital, Buenos Aires. A group of volunteers from Sumando Energias is working here, trying to equip poor people with solar energy systems for heating water.

“This is a poor area and sometimes we don't have electricity. No water. This solar panel made from recycled material helps a lot because we have children ... This is how we get warm water when we have no electricity, ”says a local resident.

How does this system work? She is brilliant and simple at the same time. It is made from used beverage bottles, plastic containers and milk bags after they have been processed.

The sun heats up the solar receiver, hot water flows into the container. Volunteers painted the pipes black to attract solar radiation. The collector maintains the temperature of the heated water throughout the night, without gas or electric heating.

“In my opinion, sustainable environmental development is an important trend in which we must develop. We are throwing away too much today, and not only in developing countries. I believe that developed countries should also follow the path of thoughtful development. Developed countries are the biggest polluters, ”says Julien Laurenson, participant of the Sumando Energias project.

A third of Argentines live below the poverty line. Nearly 17% of the population lacks water, says a study by the Argentine Statistics Agency last September.

The project provides access to renewable energy to poor people and can significantly improve the living conditions of the South American people, who have abundant natural resources. With more and more volunteers, Sumando Energias hopes to build panels for 3,000 families a year.

“Argentina has a huge potential to harness solar and wind energy. To explain better: if we had the same opportunities as in Germany, in the province of Santa Cruz - in Buenos Aires or in the north, where there is a lot of sun, we could produce energy and provide it not only to Argentina, but also to neighboring countries, ”says Pablo Castano, co-founder of Sumando Energias.

Since 2014, the nongovernmental organization has installed 36 panels and offers a two-day training course for those who want to learn the technology of recycling scrap materials into solar heaters. Volunteers involve local families in the process of building the mechanism and train them in recycling.

“There are such things, garbage that we throw away, and it pollutes the environment, but we can use it for practical purposes, for example, for hot water in the house. It is very good to recycle garbage. I've never done this before. I just threw everything away, bottles and stuff. Previously, the garbage was kept in plastic bags for a long time, because the public service did not come to pick it up, ”says Angel Guelari, a resident of Garin.

Argentina seems to be on the right track. In 2005, Buenos Aires became the first Latin American city to vote for the No Trash policy. The Argentine capital has pledged to recycle between 4 and 5,000 tons of garbage that people throw away every day. published by

PLASTIC BOTTLE SOLAR WATER HEATER

About solar water heaters (solar water collectors) in general ...

The overwhelming majority of summer residents would like to have a shower with solar water heating at their dachas. But things usually don't go further than a primitive barrel installed on the roof of a shower stall. 99% do not know to build even the simplest frame around this barrel and cover it with plastic wrap (which would increase the use of solar energy by 2 times, at least! Try to enter a closed plastic greenhouse on a sunny day!). The most advanced people insert a heating element (thermoelectric heater) into this barrel and diligently warm the atmosphere with it.
Meanwhile, probably every student knows that for every square meter of the surface perpendicular to the sun's rays, 600-1000 watts of energy fall per hour! Well, it's just a sin not to use it in the summer! When it is especially pleasant to take a shower before going to bed after a hot day, and it will not hurt to freshen up during the day. But it’s not ice cold water from a well or a well.

Those who have been to Greece or Italy probably noticed that almost every house has a solar collector-water heater. Although they are arranged in principle, quite simply, there are many nuances in their work. For example, constant water back-pressure, thermal insulation of the storage tank, organization of water circulation between the tank and the collector itself, etc.

But the independent manufacture of such systems is extremely and laborious, and expensive, and in general, with an amateurish approach, it promises more trouble than benefits.
In fact, it is necessary to make a sealed collector, organize the circulation of water and its regular replenishment, avoid mixing the already heated water with fresh cold water. And for the winter to drain the whole thing (we have here not Greece with +12 in January). And what for? Tolya is a dear iron barrel! I poured it - warmed up, poured it out for the winter - no problem. So what if she works only 10-15 times a year. But no hassle.

All these problems are keeping summer residents from creating a normal and efficient solar water heater collector.
But it seems to me that when using plastic bottles, many problems are solved. All the "charms" of the simplicity of a primitive "barrel" solar water heater remain and the advantages of a real collector with water circulation are added. And these advantages will become apparent in the course of the description of the water heater.

Solar water heater collector made of plastic bottles.

You don't need to explain what a plastic PET bottle is. Any transparent from under sparkling drinking water is suitable for the solar collector. I don’t know, I haven’t experimented with dark bottles.
If you pour water into such a bottle and put it in the sun, the water in it heats up pretty quickly. But the bottle has a very limited volume! 2-2.5 liters maximum. And in order to decently take a shower, you need at least 50-60 liters, preferably more than 100.
The main problem in creating a solar water heater is to combine many plastic bottles into a single container and organize their flow! So that cold water can flow into them, and warm water can flow out. Having solved this problem, we simply get a small transparent tank that perfectly heats water using solar energy. Taking, for example, 100 such mini-tanks, i.e. bottles, we will get 200 liters of warm water!

At the beginning, I wanted to organize the flow of the bottle by creating a special cork. For example with coaxial tubes. It flows into one, flows into the other. But making a mass of such tubes (for example 100 or 200) is no easier than making a normal classic solar collector. Therefore, I decided to go the other way - by connecting the bottles and creating a kind of transparent pipe from them, which will be both a reservoir and a collector itself. Well, like a barrel, only flat and transparent.

After measuring the diameter of the thread on the neck of the bottle, I picked up a drill that drills a hole in the bottom of another bottle. The best fit was a drill - a circular saw for drilling large-diameter holes in wood by 26 mm (sets of such files are available in abundance and cost 70-100 rubles). With this diameter, the neck of the bottle is screwed rather tightly into the hole in the bottom of the other. Sometimes you have to work with a round large file. Yes, and it is advisable to pre-drill a hole strictly in the center of the bottle with an ordinary 6-8 mm drill. I will say that this is not easy to do, because it is in the center of the bottom that there is a very hard and smooth tide - a pimple. Therefore, for mass accurate drilling, it will be better to make a simple template so that the drill does not prowl.

The next problem was the issue of sealing. Generally speaking, nothing seems to stick or stick to PET. But it turned out not quite so. Even with a drilled hole, the bottom of the bottle retained absolute rigidity, which gave hope for the use of silicone sealants. Having thoroughly degreased the surfaces with acetone, I smeared the thread of the bottle and screwed it into the bottom. And then he abundantly covered the joint with sealant and outside. For reliability, left the bottles immobile for 3 days (the fermentation rate of the sealant is 3-4 mm / day, as stated in the instructions).


Since I was just going to work out the technology and conduct an experiment, I limited myself to serial connection of only 3 bottles. The tightness of the joints turned out to be absolute! In the photo, the water bottles are on the cardboard and, as you can see, no water drips! By the way, silicone is so stuck to PET - you can't pick it off with a knife!
During a day in the sun (or rather, in just a few hours), the water heated up magnificently, even without any additional tweaks. Thus, a certain conventional collector cell was obtained - a water heater, with dimensions of 0.1 meter (bottle diameter) by 1 meter (bottle length approx. 35 cm). Those. collector area was 0.1 sq. meter, and the capacity is approx. 6 liters. It is easy to calculate that 1 sq. meter will fit about 10 such modules, the capacity of which will be 60 liters of water. On these 60 liters of water, the sun will pour out almost a kilowatt of energy every hour! Yes, this water is not just heated - you can boil it! Of course it will never boil, if only because of heat loss. But you can heat 60 liters of water to 40-45 degrees 2-3 times exactly. Which is more than enough for summer cottage needs.

Now about the water heater project itself.

For example, we make 10-20 such modules and are not 3, but 5-6 bottles long (in general, as much as the roof area facing south allows). You can, of course, use hoses to organize the full flow of all modules, but I think this is pointless. Since all the same, all the water is heated at the same time and receives the same amount of heat at any point in the collector. Therefore, we will connect our modules in parallel! And we will use it in barrel mode: poured - heated - used (or poured into a thermally insulated drive).
To connect all our modules in parallel, you need a pipe of a sufficiently large diameter (50 millimeters, or better 100, for example, polypropylene). All the modules cut into it in the same way as the bottles fit together in the module. Perhaps it would be easier to do it. After gluing or screwing the bottle cork to the pipe with a self-tapping screw and ensuring tightness, drill a hole in the cork (and the pipe, at the same time), just screw the module into the cork.


The modules, of course, must be inclined (the lower side is facing south, the common pipe is at the lowest point of the collector). A small hole, 2-3 mm, must be drilled in the topmost bottle of the module. Install a valve on both sides of the pipe. Supply water to one of them (for example, from a pump or a water tank, in Figure Vent. 2). And the other valve will be collapsible, warm water will drain through it (in Figure Vent. 1).
Works solar collector water heater as follows. Valve 1 is closed, and we begin to fill the collector with water by opening valve 2. Water fills the bottles “from bottom to top”. At the same time, air escapes from the openings at the top of the modules. Of course, as in communicating vessels, the water level in the modules is the same. Having visually determined that the bottles are full, we close valve 2 and the water heater starts its work.
If we need warm water, we open valve 1 and the heated water begins to drain from the collapsible pipe.

That's all.
Everything is exactly the same as in a barrel, only such a collector will heat water an order of magnitude more efficiently than a barrel, due to its large area.

A little about the design.
Of course, it is advisable to put the modules in a "box" to make the structure rigid. It is advisable to make the bottom of the box from a dark material that absorbs the sun's rays. For example, smoke a sheet of iron. It would be nice to place a heat insulator under the sheet, for example, thin foam or expanded polyethylene ("Penoplex"). Tighten the top of the box with plastic wrap or glass so that the wind does not cool the bottles.

The angle of inclination is minimal, degrees 10-20-30, not more.
Firstly, in summer this is the most optimal angle of inclination in relation to the Sun (almost perpendicular), and in winter this collector is not used.
Secondly, this will ensure a minimum water pressure drop (height of the water column), which is important in the presence of many bottle joints. Although during the tests I put my 3-bottle module even vertically and it "kept" the pressure of 0.1 atm., During the work I would not risk it.

The size of the entire water heater is to the taste of the creator. For 200 liters, approx. 110 bottles, which will occupy an area of ​​approx. 3 square meters. True, the power of such a heater will already be about 3 kW!
The heater can be used in pour-pour mode. Or you can arrange a thermally insulated storage tank for warm water next to it. On a good sunny day, 2-meter long, sorry, a 2-kilowatt water heater will heat you half a ton of water.

Such a water heater is not afraid of frost (except for water shut-off valves), it is not afraid of the sun either (PET does not decompose poorly in the sun).
Of course, such a solar water heater also has disadvantages (for example, poor automation), but a lot is paid off by its almost free cost. Judge for yourself what the money will be spent on. Well, a pipe, a pair of valves and 2-3 tubes of silicone sealant at 45-50 rubles / piece. And you will get water bottles as a bonus when you buy water in the store. By connecting your acquaintances to their collection, by the next season you will collect several dozen or even hundreds of bottles and you will be able to make yourself a very worthy and efficient solar water heater. Total: 300-500 rubles maximum (!!!), and you are with hot water all season!
* * *
Experimenting with the elements of a flow-through storage solar water heater made of plastic PET bottles, I once noticed that the temperature of a dark (brown) beer bottle is even higher to the touch than that of a transparent one from under water. This gave me the idea to conduct a simple experiment with bottles of different colors and types, in order to identify the most efficient ones in terms of heating.
At the very beginning, I thought that there is no better bottle for water heating than a transparent one. The sun heats the water directly, without intermediaries. How wrong I was! The very first experimental results scattered my theories to smithereens.

The experimental conditions were simple. I just put a row of bottles against the side of the barn, which faces roughly southeast. Since the conditions for all the bottles were exactly the same, I did not insulate and orient them in any way. Those. just like that, in Spartan conditions, this used PET container had to show its true character.

The bottles were prepared according to the list in the table. In doing so, I used the following considerations.

1) It was assumed that shielding the back (unlit part of the bottle) with aluminum foil would reflect IR rays not absorbed by water and reflect them back into the bottle.

2) Blackening of the back of the bottle (rubber-bitumen mastic from an aerosol can) will allow to "absorb" the infrared rays passed through the bottle. One of the bottles was completely blackened, i.e. on all sides and became black and matte.
Everything was done the day before and the next day all the bottles greeted dawn at the site of the experiment. The temperature of the ambient air (in the shade nearby) and the wind blowing over the bottles were taken into account.

The sun on this day shone through a small haze, i.e. did not give a full glow, but since everyone was on an equal footing, this can be ignored.
The results of this experiment are shown in the table. By the way, if someone thinks that water at 52 degrees is "so-so" - try to hold your hand in it for at least 2 minutes ... Just stock up on afterburn ointment more ... And at the same time measure the temperature of hot water from the tap in the apartment. It is unlikely that it will be much higher.


What conclusions can be drawn?

1. Actually transparent water is a very poor absorber of infrared rays. They practically pass through it without stopping. As you can see, the transparent bottle remains the coldest. Heating can be safely attributed to the non-absolute transparency of the bottle itself, and not the direct heating of the water in it.

2. The presence of foil on the back wall of the bottle also has little effect on heating. I don’t know why. Perhaps heating occurs only on the front wall of the bottle, perhaps the foil, in addition to the reflector lens, also plays the role of a radiator - cooler.

3. Transparent with a blackened bottom looks much better (by 8%). But obviously, a change in the angle of illumination by the sun began to affect here. As the angle of illumination changed, the area of ​​the rear absorbing surface also changed.

4. It was the completely blackened bottle that proved to be the best. The matte black surface absorbed almost all infrared rays. And since the PET bottle is round, the angle of illumination is not critical.

5. The bottles made of dark plastic also performed well. This suggests that the heat absorption of PET bottles is mainly the side facing the sun. And very weakly - by the actual "insides" of the bottle (water). And absolutely nothing - the back side.

This allows us to conclude what exactly should be a solar collector made of plastic PET bottles.
It should be a box with a well-insulated bottom, where PET bottles are placed.

The side of the bottles facing the sun should be blackened with some kind of matte paint (the same Kuzbass-lacquer or rubber-bitumen mastic). From above, close the box either with thin glass, or tighten it with plastic wrap to protect it from the wind.
Such a design of a solar flow-through or storage heater made of PET bottles will be the most efficient. By the way, the same results allow us to estimate the design of the most efficient "classic" water heater. It is quite obvious that his "mirror" does not have to be transparent at all. And if it is transparent, then the “bottom” must be absolutely heat-absorbing.
Now let's talk about the "place" of such a heater in the hot water supply system for summer cottages.
Of course, the presence of such a heater on the roof does not guarantee that you will have hot water. There are also long-term bad weather, and at night, especially in the demi-season, the water in such a heater will cool down a lot.

It seems to me that such a water heater performs 2 functions.

A) Allows you to make sure that solar water heating is possible and real for "mere pennies". After all, not everyone decides to build a solar collector out of the blue, investing in solid money for the sake of the still ephemeral saving of electricity, firewood, money. This water heater for 500 rubles will pay off in a season and let you feel the beauty of the moment.

B) This water heater will REALLY save you money in the form of firewood, electricity, gas, etc. working as a water treatment system for ANY industrial water heater.

Hot water consumption in each family is different. But in any case, it should be and always. Therefore, as soon as the heating of the water in the solar collector ends, it should immediately be sent to a well-insulated storage tank, from which hot water is consumed. In the same storage, a heating element must be installed, which will allow you to get hot water during a period of prolonged bad weather. Or you can bring a wood-burning water heater to it.
But in any case, the solar water heater itself is only part of the hot water preparation system. Then hot water will be in the house or shower always and around the clock. Although of course it can be used on its own. Just hot water will be ready for dinner.

"Encyclopedia of Technologies and Techniques" Patlakh V.V. 1993-2007

Project concept

The essence of the solar collector is that cold water from the reservoir flows by gravity into the collector. The heated water rises through the channels and goes back to the reservoir. Thus, natural circulation is created in a closed system.
The manifold is made from a sheet of polycarbonate or other plastic with hollow squares running along the inside. To increase the absorption of sunlight and improve the collector's performance (the rate at which the water heats up), the plastic can be painted black. But here it is important to remember that the sheet is made of rather thin polycarbonate, therefore, with strong heating in the absence of circulation, it can soften or deform, which will entail water leakage.
It is also worth noting that this device is not suitable for installation in residential premises for the purpose of hot water supply. This experimental project is more suitable for equipping a summer shower in a summer cottage.

Tools and materials

Of the tools you will need:

• Circular and hand saw.
• Electric drill.
• Roulette.
• Screwdriver.
• Silicone glue gun.
• Construction stapler.

Materials for the collector:

• Polycarbonate sheet with hollow channels.
• ABS tube.
• 4 caps for tubes.
• 2 ½ inch plastic nipples with thread and hose connection.
• Silicone sealant tube.
• Spray paint, if painting is planned.

Frame materials:

• 1 sheet of plywood.
• Expanded polystyrene sheet. You can also use Styrofoam squares.
• Wooden beam with a section of 100 × 100 mm.
• Plastic wrap, scotch tape.
• Bolts, nuts, washers, brackets for fastening.

Materials for organizing water circulation:

• A suitable water tank or container.
• To connect the tank, you will need a garden hose, the length of which depends on the distance of the water tank from the collector itself.
• Several hose clamps.

For clarity of testing the performance of the water-heating collector, I used a digital thermometer.

Step-by-step technology for assembling a solar collector

First of all, you need to cut the polycarbonate sheet to the required dimensions. I planned to make a collector measuring 1 × 2 meters, and proceeded from this fact. The order of work is as follows:

In order for the sealant to dry well, the assembled structure must be left stationary for about a day, after which you can proceed to the tightness test. To do this, hoses are connected to the input and output adapter, one of which is connected to the water supply. After the manifold is completely filled with water, all seams and connections are checked for leaks. If a leak is detected, the water is drained and, after drying, the problem joint is sealed again.
To be able to calculate the productivity and efficiency of the reservoir, you need to know its volume. To do this, the water from the collector must be drained into a container. For example, my dashboard contains 7.2 liters (including hoses).

Frame fabrication and panel assembly

In principle, the collector can already be used by placing it on a roof or other flat, fixed surface. But I decided to make a kind of case for the plastic panel in order to reduce the likelihood of damage when lifting / lowering from the roof of the shed, in which I decided to equip an outdoor shower, since I am thinking of removing it for the winter.
The phased assembly of the case is described below:

Thus, I got a heat collector in a reliable "case", thanks to which the plastic panel is protected from mechanical stress.
Note! I used regular transparent polyethylene, but in the photo it looks as if it is white - these are highlights.

Filling the system

Now you can fill the manifold with water and test the functionality of the system. I set it tilted and the tank (empty) a little higher. One hose connects to the bottom fitting, the other to the top. To fill the system with water, I connected the lower hose to the water supply and opened the valve slightly so that the system is filled with water gradually. This is necessary so that the water gradually displaces all the air. When water came from the second hose (the collector was completely filled), I opened the valve all the way so that the remaining air would come out under the water pressure. I also filled the water tank.

When air bubbles ceased to be observed in the flow of water leaving the outlet hose, I shut off the water, and immersed both ends of the hose in water in the tank (they should always be under water so that air does not enter the system).

Solar Water Heater Testing and Testing

When the system is full, under the influence of solar heat, the water in the thin channels of the plastic panel heats up and gradually moves upward, forming a natural circulation. Cold water comes from the tank through the lower hose, and the heated water in the manifold enters the same tank through the upper hose. Gradually, the water in the container heats up.

For clarity of the experiment, I used a digital thermometer with an external temperature sensor. First, I measured the temperature of the water in the tank - it was 23 ° C. Then I inserted the sensor into the outlet hose, through which the water heated in the manifold enters the reservoir. The thermometer showed 50 ° C. The solar water heating system is working!

Conclusion

According to the results of testing the operability of the collector system for 1 hour, I got 20.2 liters of water heating (7.2 liters in the collector itself and 13 liters in the container for the experiment) from 23 to 37 ° C.
Of course, the performance and efficiency of the system depends on solar activity: the brighter the sun shines, the more the water will heat up and you can heat up a larger volume in less time. But for a summer shower, I think this collector is enough.

Every year, the problem of providing your country house or summer cottage with hot water becomes more and more urgent. Especially often the owners of the cottages in which they live permanently reflect on this problem. After all, the cost of heating and hot water supply takes a significant share in financing the life support of the home. And the search for opportunities to reduce the cost of maintaining a house is a normal and natural desire of any person. Of course, the most realistic option is to reduce the cost of heating a house, to study and start making devices from the field of alternative energy with your own hands.

The fact that a selective renewable energy device used for heating a house has many undeniable advantages has been known for a long time, and almost every adult knows about it. However, in practice, not every one of these adults, who want to become more autonomous in matters of water heating, decides to shell out a decent amount of money to purchase a factory-made selective home heating device. Of course, you can find a way out of any situation, and even more so from this. You can make a solar collector for heating a house with your own hands. You can easily assemble a flat, air solar collector yourself. These self-made solar water heating devices can be made from beer cans and plastic bottles by connecting them with a hose and vacuum tubes. As a result, you will get an absorber of solar energy for heating your house by heating water, the manufacture of which will require almost no financial investment from you (especially when choosing the option from cans).

What materials will you need to make a homemade absorber

It seems to the average man in the street that it is incredibly difficult to make a solar-powered absorber for heating your home on your own, having carried out your own production of every detail that makes up the device. However, in order to make such an absorber, which will act as a device for heating water in the heating system of a house, you do not need to purchase or search for some exotic materials. You don’t have to go around a bunch of stores looking for the right hose, looking for vacuum tubes. Do not worry - this is all speculation of lazy people and people who are afraid to get down to business. The main thing is to take a balanced approach to solving the problem, plan everything correctly, draw a diagram and select the necessary materials.

A homemade Selective Coated Flat Air Absorber can be made from common HDPE materials and components. Polycarbonate vacuum tubes and other parts can be purchased at low prices at any hardware store or supermarket. The assembly diagram is quite simple; for training purposes, you can watch a video on the World Wide Web (there are more than enough such videos). In fact, on the global network, you can find a lot of specialized literature on this problem. If you decide to do the intended work at a high-quality level, reading a certain amount of literature will not be superfluous.

The main difficulty in the assembly process is how exactly to make the coil (this is a tube in a tortuous shape through which fluid circulates, carrying out the accumulation of energy). There are several options based on which the assembly diagram will be drawn up. The easiest option is to assemble an absorber based on a ready-made coil (you can try to look for something suitable for these purposes, it is important that it is vacuum). Alternatively, the circulation system located on the back of the refrigerator may be suitable. The second option is to pick up the necessary vacuum tubes, two or three hoses, a couple of plastic water bottles (the coolant is collected from them). Watch the tutorial video again for more confidence. It is better to use copper pipes for heating water. Next, you need to do the soldering of the coil itself.

The second very important element that goes into the absorber is the upper side made of transparent polycarbonate. In industrial conditions, polycarbonate coating is not used, the front coating is cast from a tempered glass alloy. However, in our case, a homemade air manifold is considered, the thermal circuit and the required efficiency of which allows the use of polycarbonate, since we will assemble the device from available inexpensive materials. It is worth noting that there are assembly schemes where materials are used from beer cans to the use of plastic bottles.

Preparing to assemble the absorber

So, in assembling your device, you'd better resort to using cellular transparent polycarbonate. The use of this type of polycarbonate will allow you to achieve maximum heating efficiency from the device being created. It is also worth making a choice in favor of this polycarbonate because it is very durable. This is important, considering possible weather disasters, such as large hail, hurricane air flow that rips branches from trees - these accidents must be taken into account, as they can damage weak coverage. The honeycomb structure of the coating will help you create an airy greenhouse effect, resulting in an increased moment of heating the water in the tubes. Simply put, by using this material and in addition to selective coating, you will significantly increase the efficiency of the product.

For an absorbent panel, you will need a sheet of metal that is about 0.8 millimeters thick (copper is better, however). In principle, steel sheet will do. The outer surface will need to be coated with a so-called selective coating (paint with matte black paint, the paint must be resistant to high temperatures). If you do not follow these recommendations (black coating is also meant), the device will not function in the correct mode.

In addition to the listed components, purchase the mineral wool necessary for thermal insulation, it will create a kind of air trap, minimizing heat exchange with the surrounding space, transferring all the heat to the coil, and then through the hose to the heating system of the house.

You can also assemble the body of the device yourself, for this you need to use aluminum materials or use a less durable but easier to process wood material. Working with wood, you will spend significantly less time creating a heater, and plywood is even easier to work with. But still, it is better to use an aluminum frame, its durability, in comparison with wood, cannot be compared in any way.

Determining the size of the collector

Now let's summarize, we list all the materials necessary for assembling an effective home-made collector:

• Copper tubes with dimensions of 18 millimeters - from which you will form a coil (the same tubes are used when assembling heating systems);
• matt black paint, resistant to high temperatures (with its help you will apply a selective coating);
• mineral wool (thermal insulation);
• sheet of metal (copper, iron, steel), sheet thickness 0.8 millimeters in thickness;
• corner transitions 18 x 18 millimeters;
• plumbing transitions 18 mm x ¾ (needed in order to connect to the water supply system);
• cellular polycarbonate (collector front cover);
• aluminum sheet and aluminum corners to create the product body, if there are none - wooden planks and a plywood sheet for the rear wall of the heater;
• all the tools necessary for soldering work.

It is important to determine in advance the dimensions of your collector based on its dimensions, calculate in advance the required number of pipes, transitions and other materials (in other words, the overall performance of the mounted device). Calculate the amount of water that will be required to provide heat exchange throughout the system. To do this, decide in advance for what purposes the collector will be used - either it is just washing dishes, or for a shower, or to ensure that all household needs of hot water supply in your home are covered. To heat water for washing dishes or taking a shower, it will be enough to assemble a collector measuring 200 x 100 centimeters, the distance between the tubes in the coil should be from 8 to 10 centimeters.

DIY solar collector assembly process

The beginning of the assembly of this solar energy product starts with the manufacture of the coil. If you can find a complete coil, the final assembly will take much less time. The selected coil should be very thoroughly washed under running water (preferably hot) in order to wash out all blockages from the inside and get rid of freon residues. If you have not found suitable tubes, then you can purchase the required amount in the store. But in this case, you will have to make the coil itself. To make it, cut the tubes to the required length. Next, using corner transitions, solder them in the form of a coil structure. Further, so that the collector can be connected to the water supply system, solder plumbing transitions with dimensions ¾ to the edges of the coil. There are several options for the shape and design of the coil, for example, you can solder the tubes in the form of a "ladder" (if you are going to implement this option, then buy non-angular transitions, you will need tees).

Then, on a pre-prepared sheet of metal, you apply a selective coating with black matte paint, it is advisable to do this in at least a couple of layers. Wait for the airflow to dry the paint and start soldering the coil (unpainted side). The entire coil structure must be soldered along the entire length of the tubes, by doing this, you guarantee the most efficient heat exchange and, as a result, the maximum transfer of heat to the water supply system. If you do everything correctly, the solar collector you assembled will work as intended.

Responsible assembly stage

The final step is to assemble the case, which will hold all the components of the device together into a single structure. Using a sheet of plywood and wood blocks, knock down a sturdy box. In the used wooden blocks, cut the grooves in advance, into them you then insert a polycarbonate screen (the groove depth is about 0.5 cm). Tubing outlets can be made after all major components have been installed. Next, in an already assembled wooden box to create an air pocket, you put mineral wool insulation. Fasten a panel with a coil on top of the mineral wool. Tuck the edges of the cotton so that the coil does not touch the walls of the box. The heating panel and the polycarbonate panel must also have a distance between them and not touch each other.

The final stage consists in treating the case with a special solution with a water-repellent ability and covered with enamel (except for the front part).

That's all, the solar collector is ready with your own hands. In order to activate it, place it on a support structure, facing the sun in such a way that the rays fall on the front at the most right angle. Install a water storage tank on the roof; it will serve as a reservoir. From the top of the tank, run the hose from the top pipe of the manifold to the bottom of the bottom pipe. By connecting the water according to this scheme, you will ensure operation in the natural circulation mode. According to the laws of physics, hot water will rise up towards the tank, and the displaced cold water will enter the manifold for heating in the coil. Do not forget that a hose and a valve must be connected to the tank for taking water from the tank, as well as filling it with a new one.

When it's hot outside, the amount of rubbish such as plastic bottles increases dramatically in the world. These are bottles from mineral water, from juices, beer and much more. One author suggested a way how this material can be used to create a very useful homemade product. We are talking about a device such as a solar collector, which allows you to get free hot water from solar energy.

The author of this homemade product was a Brazilian named Jose Alano. Its peculiarity is that such a collector is able to actively work both at sunrise and sunset. The thing is that the sun's rays penetrate the bottle and heat the water. If we talk about collectors with glass, then there the sun's rays are reflected from the surface, if they do not pass at an angle close to 90 degrees.

DIY materials and tools:
- plastic bottles (their number depends on the scale of the collector);
- tetra paka from juice or milk;
- PVC pipe with an outer diameter of 20 mm and tees (you can use a copper pipe, but this is an expensive material);
- cardboard;
- stationery knife;
- black heat-resistant paint;
- scissors;
- storage tank.

Manifold manufacturing process:

Step one. Preparing bottles
To create a collector, you need bottles of the same shape, so you need to try a little and find the right amount of them. This is necessary so that you can insert bottles into each other, thus forming a chain of bottles.

When the bottles are found, you need to wash them and remove the labels. Next, cardboard is taken and a template is made from it. Subsequently, using this template, the bottoms of the bottles need to be cut off at a given level. It is convenient to do this with a clerical knife.

Step two. Making an absorber
To make an absorber, you will need a container for milk or juices (tetra paki). The bags need to be rinsed thoroughly, as the contents will sour when heated and give off an unpleasant odor. After drying, the material is cut as shown in the pictures. After that, it must be painted with black paint (heat-resistant).

Step three. We collect the collector
The heat exchanger is assembled from PVC pipes with a diameter of 20 mm. For these purposes, you need to use only those pipes that are intended for hot water supply. The corners and tees at the top are connected with PVC glue. To improve the efficiency of the collector, the pipes must be painted black.

The structure is assembled as follows. First you need to take the bottle and put it on the bottle with the neck first. Then an absorber (tetra pack) is taken and inserted into the bottle until it stops. The length of the pipe is about 105 cm, while the number of bottles collected in this way should not be more than five.

Step four. Installing the manifold
You will need a wooden or metal support to install the manifold. It needs to be turned so that the sun falls on it, you need to focus on the south.

In order for water to circulate naturally, the tank must be placed at a level above the collector. Now cold water will go down, as it is heavier, and hot water will expand and flow into the tank. The distance from the collector to the tank should be at least 30 cm, then the circulation will take place with the required intensity. Thanks to this approach, no pumps are needed. The tank needs to be insulated to reduce heat loss.

The system can also be equipped with a turbulent gearbox. It is needed so that hot water flows into the tank smoothly and without pressure, while smoothly mixing with cold water. It is made from a bottle with a closed bottom, you need to make a number of holes in it.