Homemade solar water heater from plastic bottles. Plastic bottles - material for creating a solar collector Collector from plastic bottles

C solar collector made of PET bottles

Konstantin tymoshenko
Source: delaysam.ru

Two years ago, I experimented with PET bottles to make a solar water heater out of them - a collector that would holiday season would supply my family hot water both for washing and for household needs. And finally, this year, his hands reached him.

Having accumulated a lot of PET bottles over the winter drinking water, I decided to make a solar collector out of them - a water heater. I also bought a pipe made of polypropylene with a diameter of 50 mm, a pair of plugs - plugs and set to work. The length of the pipe fit 20 PET bottles of 2 liters each. Thus, the volume of the solar collector had to be about 40 liters of water. The volume is quite sufficient for daily needs in terms of washing dishes and bathing.

Drilled in a pipe right amount holes for bottles, I ran into the problem of sealing the junction of the bottle and polypropylene pipe. silicone and acrylic sealants flatly refused to stick to it and flew off like leaves from a cabbage head. It seems to hold tight, but a little pressure - it leaves entirely. The solution was found in the use of hot glue. But even here there were some surprises. The glue seemed to adhere well, but also peeled off in layers. I had to take a soldering iron and carefully rub (fuse) the glue into the polypropylene around the perimeter of the hole. I had to do the same with bottles. Glue had to be melted into their necks. After that, it was possible to glue the bottles firmly and securely into the pipe.

In one of the end caps, I cut a fitting for connecting to the water supply. The water heater was supposed to be storage. Those. with the opening of the tap, it was filled with water (40 liters), the water was heated and drained into a thermos storage tank. The bottles were supposed to be at an angle of about 20-30 degrees, neck down. So that the air in the bottles does not interfere with filling them with water, a small hole (2-3 mm) was made in the very top of all the bottles.

In order to prevent the collector from “driving around” under the weight of the water that filled it, a box was made of a board 150 mm wide. A layer of 50 mm expanded polystyrene was laid on the bottom of the box and covered with household foil on top. This is done to insulate the PET bottles and to improve the efficiency of the solar collector.

So, the whole system was packed in a box and connected to the plumbing system. I covered the bottles with black matte spray paint, remembering my experiments with PET bottles for heating water (Solar flowing- storage water heater read below). After filling the solar collector with water, I inserted a sensor from an electronic thermometer into one of the bottles to monitor the temperature of water and air.

The body of the solar collector itself was oriented to the east (alas, the roof was already ready ...). But since its slope is quite small (about only 20-25 degrees), the efficiency loss should have been small. In fact, it could be considered that the collector is located almost horizontally.

The first day of work of the collector turned out to be "partly cloudy". But there was a lot of sun and the water warmed up by 48-50 degrees by 14 o'clock. The body of the collector was not closed by anything, and since the wind was of medium strength, I understood that the bottles were both heated by the sun and cooled by the wind. Yes, and 50 degrees for hot water - not so much. Washing up, washing dishes is fine. But without a “reserve”, even such water drained into a thermos will quickly cool down even the next day.

So I decided to windproof the bottles with a few pieces of glass that I have had from time immemorial. I glued the glass at several points with silicone sealant, but left micro-slits for ventilation in case it was fogged up.

The day was not clear, but also partly cloudy. But the air was clear, almost without haze. Therefore, the sun shone brightly, although not "100%". With the installation of glasses, heating began to occur much more intensively than without them ... The temperature was 50 degrees ( initial temperature water temperature of about 15 degrees) was reached by about one o'clock in the afternoon and then continued to rise, although the sun crossed the "perpendicular" to the plane of the solar collector.

At about 4 p.m., “a terrible thing happened.” When the water temperature reached 65 degrees (which I never dreamed of), the collector simply began to collapse! The hot melt adhesive softened so much that it could no longer withstand even the minimum water pressure and the junctions of the PET bottles and the polypropylene pipe began to “cry”. But it's still half the trouble. The PET bottles themselves began to warp! It is clear that the temperature of their "case" exceeded the limit for PET and was higher than the temperature of the water. I knew that PET warped at high temperatures, but I did not expect that this temperature would be reached in a solar collector of a primitive design. Thus, my solar collector - water heater ceased to exist during the "tests".

What conclusions can be drawn from this experiment?

1. Can be made simple and extremely cheap solar water heater- a collector from PET bottles. Its cost will not exceed $10! Bottles - shareware, pipe 2 meters 50 mm - 60 rubles, a pair of plug caps - another 40 rubles. A pair of hot melt adhesive rods - 30 rubles. fitting for connecting to the water supply, cutting foam, boards, glass or plastic film ...

The only drawback is that the temperature of the water heated by it should not exceed 50-55 degrees. Otherwise, the solar collector will be destroyed. The hot melt problem can be solved by making fittings. For example, take a tube (aluminum or copper), and cut into it outside carving. And with a pair of nuts, fix the bottle cap on the water supply manifold. And the bottle is simply screwed into its own cork.

In principle, this water temperature (50 degrees) is sufficient for household needs. Perhaps in the hottest months of summer, it is not worth increasing the efficiency of a solar water heater. Let it be a little underheated than melt. And in the demi-season months - it is worth covering the collector with glass.

2. The potential of the solar collector - water heater even in middle lane Russia is! And the potential is huge! From April-May to September inclusive (in fact, the entire summer season), a solar collector - a water heater of the proper size and design can provide hot water to an ordinary family, while saving hundreds (or maybe thousands) of rubles family budget that are spent on electric water heaters and their operation.

Of course, you should come up with something more reliable and heat-resistant than PET bottles for use in a solar collector - water heater. And of course - the budget. Take aluminum cans for example.

Solar instantaneous storage water heater from PET bottles

While experimenting with the elements of a flow-accumulative solar water heater made of plastic PET bottles, I somehow noticed that the temperature of a dark (brown) beer bottle is even to the touch higher than that of a transparent one from under water. This gave me the idea to do a simple experiment with bottles. different colors and types, in order to identify the most efficient of them in terms of heating.

At the beginning, I thought that no better bottles for water heating, rather than transparent. The sun heats the water directly, without intermediaries. How wrong I was! The very first results of the experiments dispelled my theories to smithereens.

The conditions for the experiment were simple. I just lined up a row of bottles against the wall of the shed, which faces roughly southeast. Since the conditions for all the bottles were exactly the same, I did not thermally insulate and orient them. Those. just like that, in spartan conditions, this used PET container was supposed to show its true character.

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 the IR rays not absorbed by the water and reflect them back into the bottle.

2. Blackening the back of the bottle (with rubber-bitumen mastic from an aerosol can) will allow you to “absorb” the infrared rays that have passed through the bottle. One of the bottles was completely blackened, i.e. from all sides and became black and matte.

Everything was done the day before and the next day all the bottles met the dawn at the place of the experiment. The ambient temperature (in the shade nearby) and the wind blowing over the bottles were also taken into account.

The sun that day shone through a small haze, i.e. did not give full heat, 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 holding your hand in it, at least for 2 minutes ... Just stock up on more post-burn ointment ... And at the same time measure the temperature of hot water from the tap in the apartment . It is unlikely to be much higher.

What conclusions can be drawn?

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

2. The presence of foil back wall bottles also have 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 acts as a radiator-cooler.

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

4. It was the completely blackened bottle that showed itself best of all. The black matte surface almost completely absorbed IR rays. And since the PET bottle is round, the angle of illumination does not matter.

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

This allows us to conclude that what actually 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 plastic wrap, for wind protection.

Such a design of a solar flow or storage heater made of PET bottles will be the most effective. By the way, these same results allow us to estimate the design of the most efficient "classic" water heater. It is quite obvious that its “mirror” does not have to be transparent at all. And if it is transparent, then the “bottom” should be absolutely heat-absorbing.

Now let's talk about the "place" of such a heater in the country hot water supply system.

Of course, the presence of such a heater on the roof does not guarantee that you will have hot water. There are also prolonged bad weather, and at night, especially in the demi-season, the water in such a heater will cool down greatly.

I think that such a water heater performs 2 functions.

A)Allows you to make sure for “mere pennies” that solar water heating is possible and a reality. After all, not everyone will decide to build a solar collector like this from the bay, investing in solid money for the sake of the ephemeral saving of electricity, firewood, and money. This water heater for 500 rubles will pay off in a season and will let you feel the charm 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.

But in any case, the actual solar water heater 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.

The concept of alternative energy for many owners of private houses and summer cottages is associated with expensive solar panels, windmills or heat pumps. No one even realizes that in just a few hours, for mere pennies, you can build a solar collector from plastic bottles to supply yourself with hot water throughout the warm season.

We will tell you how from waste materials do effective system preparation of sanitary water. In our article, you will find detailed description designs and methods of manufacturing systems, the operation of which has been tested in practice. Taking into account our recommendations, you will assemble a device useful in the household without any hassle.

The main difference between a solar collector and various types generating heat is the cyclical operation. In other words, in the absence of the sun, there will be no thermal energy.

It is obvious that in dark time days, the performance of an autonomous hot water supply with a solar collector is reduced to zero. The production of heat by a solar collector is determined by the length of daylight, which depends on geographical latitude and time of year.

A self-made solar collector will solve not only the issue of supplying hot water to a house that is not connected to central networks, but also heating problems

The climatic features of the area also have a significant impact on the level of performance of the solar collector. If the area is characterized by frequent fogs or the sun is often hidden behind clouds, then the performance of the solar collector is significantly reduced.

However, in this case, and / or water heating remains effective, due to the ability to capture even scattered rays.

Design features and principle of operation

main element standard variant The solar collector is an adsorber in the form of a copper plate with a tube. The plate quickly warms up under the action of sunlight, transferring heat to the tube and the liquid in it. Thanks to free or forced circulation The resulting heat is then transported throughout the system.

Under the action of sunlight, the copper plate is heated, from which heat is transferred to the coolant in the tube

To increase the efficiency of the adsorber, it is necessary to provide it with the necessary physical properties. First of all, it is necessary to increase the absorption capacity of the adsorber and minimize the reflection of sunlight. by the most simple solution black paint will be applied to the adsorber.

To increase the efficiency of the adsorber, it must be covered clear glass. Ordinary glass reflects some of the sun's rays.

Best to use special glass with a low content of iron in its composition or apply an anti-reflective coating. To avoid contamination of the glass, the body of the solar collector should be sealed.

Despite the mass of ways to improve the performance and increase the performance of the solar collector, yet due to the imperfection of the design this indicator far from ideal. Taking into account the principle of operation of the solar collector and methods for increasing its efficiency, we will try to create a primitive and inexpensive model from improvised materials.

Assembly of the unit from improvised materials

In addition to being cheap and easy to assemble, the plastic bottle option differs from standard solar devices in that flat solar collectors do not work well in the morning and evening hours.

The convex shape of the bottles provides an almost vertical penetration of the rays even during sunset and dawn, thereby ensuring the efficiency of the device, both in the morning and in the evening.

There are several distinctive ways to build a perfectly working hot water system from plastic bottles:

solar collector plays the role of a storage tank in which water is heated and then drained;
The solar collector is connected to a storage tank to ensure water heating and its natural circulation;
The plastic bottles of the collector act as a water reservoir;
Plastic bottles play the role of airtight containers to keep warm.

Also, solar collectors can differ in their design features. First of all, this is due both to the way the bottles are attached and the way they are located.

Hot water storage option

For the manufacture of a solar collector, a diameter of 50 mm is required, to which plastic bottles will be connected, the number of which is determined by the diameter of the pipe. For the template, 15 plastic bottles were taken, so the working capacity of the solar collector was 30 liters.

To connect bottles into a single system in propylene pipe intended for hot water supply, it is necessary to drill holes. The ideal solution was use pen drill on wood with a diameter of 26 mm.

With such dimensions, the maximum tightness of the connection is ensured, and the bottle is screwed into the hole with force along its thread. To ensure maximum sealing of the joint, the joints can be coated with silicone sealant, but it is better to use hot melt adhesive.

To achieve the effect of communicating vessels in the upper part of each of the bottles, it is necessary to make holes with a diameter of about 2 mm.

After connecting the bottles, a fitting is cut into one side of the pipe, which will later be connected to the water supply system for water supply. On the other hand, a tap should be inserted through which the heated water will drain into the storage tank.

However, under the weight of the filled water, such a device for domestic use may lose its integrity. Therefore, a box device would be appropriate. For its manufacture, a board with a width of 150 mm is required.

To increase the efficiency of the solar collector, 50 mm thick polystyrene foam or expanded polystyrene can be laid on the bottom of the box and covered with foil.

After installing the solar collector in its place further exploitation plastic bottles must be painted black to absorb sunlight more effectively.

Paint is best used matte and applied by spraying from an aerosol can. It remains to cover the box with glass, thereby increasing its tightness and connect it to the cold water supply system and the drain system prepared for use warm water into the storage tank.

It is known from practical experience that plastic does not tolerate impact well. high temperatures leading to its deformation. On bright sunny days, the temperature of the heated water can exceed 65 degrees, which will lead to deformation of the plastic.

In this regard, it is better to refuse additional sealing of the box with glass in general, or use it exclusively in cloudy weather.

Hot water circulation method

The solar collector device system is similar to the first option, but has a number of structural differences.

To create a collector, you will need the following tools and materials:

Pipe PVC diameter 20 mm with corners and tees;
Roller pipe cutter;
Chamfer cutters;
Primer (cleaner);
Plastic bottles;
Tetrapacks from under milk or juice;
Stationery knife;
Cardboard;
Heat-resistant matte black paint;
Storage tank.

For installation, we need a PVC pipe with a diameter of 20 mm. The horizontal part of the pipe should be cut into segments into which, by cold welding corners and tees will be attached. Bottom part solar collector will look exactly the same. In the end result, we get a closed system, but first things first.

Features of gluing PVC pipes

To obtain a high-quality cut, it is better to use one equipped with rollers. After cutting, the inside of the pipe must be chamfered using special chamfer cutters.

After measuring the depth of the tees and angles, you need to set a mark on the end of the pipe to be connected and treat the ends of the pipes and fittings with a primer (cleaner).

The next step is to apply and spread the adhesive over the outside of the pipe and the inside of the fitting. The adhesive must be applied with a brush, while its size should be smaller than the diameter of the pipes. It remains to insert the pipe into the prepared tee or corner and turn it a quarter of a turn to evenly distribute the glue.

It should be noted that the work on gluing one corner or tee should be completed in no longer than 30 seconds. After fixing, it is necessary to remove the remaining adhesive.

The procedure for manufacturing a solar collector

After preparing the top pipe and attaching vertical pipes to it, you can begin to prepare plastic bottles. In the presented solar collector model, there are 4 vertical pipes 105 cm long, 5 plastic bottles can be placed on this pipe length. That is, to assemble the collector, you will need 20 identical plastic bottles.

The bottom must be removed from each bottle. To do this, make a simple template from a 30 cm long piece of cardboard rolled into a tube. Using a template and a clerical knife, remove the bottom on the bottles. After preparing the bottles, you can begin to manufacture an absorber that will absorb solar energy.

Usage simple template from cardboard makes it possible to quickly cut and get bottles of the same size

As an absorber, we use used tetra packs from juice or milk. They must be cut, washed and dried thoroughly. To improve their absorbency, matte black paint should be applied. The easiest way to do this is using spray paint by spraying.

Consistent stringing of plastic bottles makes it easy to place folded tetra packs in them

After preparing the bottles and tetrapacks, you can begin to assemble the solar device. First, you need to string a plastic bottle with the neck forward onto a vertical tube and insert a tetrapak into it. In a similar way, all bottles are strung on vertical tubes, which then must be connected to the tees and corners of the lower tube, similar to the upper one.

To give rigidity to the manufactured solar collector, it is necessary to make a support for it.

It is possible, as in the first case, to place the collector in wooden box, but it is no longer necessary to insulate it. Since each of the plastic bottles is a kind of small insulated reservoir, which, warming up from the inside, transfers heat to the water circulating through the tubes.

Features of placement and connection

For the maximum possible absorption of sunlight, the collector must be oriented in a southerly direction. Enough small angle tilt of 10-15 degrees, so that the collector works effectively in almost any position of the sun.

The lower part of the pipe must be connected to the bottom of the storage tank, and the upper part to approximately its central part. Cold water from the polymer tank will flow through the lower pipe to the collector, where it will heat up and rise through the upper pipe to the tank.

Thus, the natural circulation of water through a makeshift system will be carried out. To provide high intensity water circulation, the tank should be placed just above the solar collector at a distance of at least 0.3 m from it.

It should be taken into account that when cold water enters the tank from the water supply system, it is actively mixed, which reduces the efficiency of the collector. This can be avoided by equipping the inlet to the tank with a turbulent reducer, which is a plugged tube with multiple holes.

Water flows smoothly through the reducer, which allows cold water to remain in the lower layers, from where it is drawn into the solar collector.

Obviously, the solar collector provides water heating only in daytime in sunny weather. Therefore, it is important to save hot water for use during the day and in the evening. To do this, it is necessary to insulate the storage tank.

Conclusions and useful video on the topic

Video 1. This is how the first solar systems from plastic bottles appeared:

Video 2. A practically free water heater in action:

solar collector from plastic containers for drinks - a cheap solution for obtaining hot water. However, in case of prolonged bad weather, especially in spring and autumn, it is advisable to install a heating element in the storage tank. In this case, the solar collector will become part of a complete system that allows favorable conditions save money.

Tell us about your experience in building a homemade solar system from plastic bottles. It is possible that in your arsenal there are information and design options that may be useful to site visitors. Please write comments in the block form below, ask questions, share photos and useful information.

SOLAR WATER HEATER FROM PLASTIC BOTTLES

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

The vast majority of summer residents would like to have a shower with solar water heating in their country house. But things usually do not go further than a primitive barrel installed on the roof of a shower stall. 99% have no idea to build even the simplest frame around this barrel and cover it with plastic wrap (which would increase the use solar energy 2 times at least! Try to enter a closed film greenhouse on a sunny day!). The most advanced ones insert a heating element (thermoelectric heater) into this barrel and diligently heat the atmosphere with it.
Meanwhile, probably every student knows that for every square meter surface perpendicular to the sun's rays, falls 600-1000 watts of energy per hour! Well, it's just a sin not to use it in summer time! When it is especially pleasant after a hot day to take a shower before going to bed, and it will not hurt to refresh yourself during the day. But not ice-cold water from a well or a well.

Those who have been to Greece or Italy have 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 supply, thermal insulation of the storage tank, organization of water circulation between the tank and the collector itself, etc.

But self-manufacturing such systems are extremely laborious and expensive, and in general, with an amateurish approach, it promises more trouble than benefit.
In fact, it is necessary to make a hermetic collector, organize the circulation of water and its regular replenishment, avoid mixing already heated water with fresh cold water. And for the winter, the whole thing is drained (we don’t have Greece here with +12 in January). And what for? Tolya is dear iron barrel! Poured - warmed up, drained for the winter - no problem. So what if it works only 10-15 times a year. But no hassle.

These are all problems that keep 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 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 from plastic bottles.

What is a plastic PET bottle, you do not need to explain. For a solar collector, any transparent from under carbonated drinking water is suitable. Although 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 max. And in order to take a decent shower, you need at least 50-60 liters, preferably more than 100.
The main problem of creating a solar water heater is to combine many plastic bottles into a single container and organize their flow! To cold water could flow into them, and warm - flow out. Having solved this problem, we simply get a small transparent tank that perfectly heats water due to solar energy. Taking, for example, 100 such mini-reservoirs, i.e. bottles, we will already get 200 liters of warm water!

Initially, I wanted to organize the flow of the bottle through the creation of a special cork. For example with coaxial tubes. It flows into one, flows out into the other. But the manufacture of a mass of such tubes (for example, 100 or 200) is no easier than the creation of a normal classical 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.

Having measured the diameter of the thread on the neck of the bottle, I picked up a drill with which a hole is drilled in the bottom of another bottle. Best fit drill - hole saw for drilling holes large diameter on wood by 26 mm (sets of such files are commercially available in abundance and cost 70-100 rubles). With this diameter, the neck of the bottle is screwed quite tightly into the hole in the bottom of the other. Sometimes you have to work with a large round file. Yes, and it is advisable to pre-drill a hole strictly in the center of the bottle with a conventional 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 - pimples. Therefore, for mass precision drilling, it would be better to make a simple template so that the drill does not scour.

next problem There was a sealing issue. Generally speaking, nothing seems to stick or stick to PET. But it turned out not quite so. Even with drilled hole, the bottom of the bottle retained absolute rigidity, and this gave hope for the use of silicone sealants. Having carefully degreased the surfaces with acetone, I smeared the threads of the bottle and screwed it into the bottom. And then abundantly smeared the joint with sealant and outside. For reliability, I left the bottles motionless for 3 days (sealant fermentation rate 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 a series connection of only 3 bottles. The tightness of the joints turned out to be absolute! In the photo, water bottles are on 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 superbly even without any additional tricks. Thus, a certain conditional cell of a collector - a water heater was obtained, with dimensions of 0.1 meters (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 per 1 sq. meter will fit about 10 of these 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 only heated - you can boil it! Well, 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 country needs.

Now about the water heater project itself.

For example, we make 10-20 such modules and not 3, but 5-6 bottles long (in general, as much as the south-facing roof area allows). It is possible, of course, with the help of 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 storage tank).
To connect all our modules in parallel, you will need a pipe with a sufficiently large diameter (50 millimeters, and preferably 100, for example, polypropylene). All modules crash into it in the same way as the bottles are joined to each other in the module. It might be easier to do it. After gluing or screwing a bottle cap to the pipe with a 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, should be inclined (the bottom side is facing south, the common pipe is at the lowest point of the collector). In the topmost bottle of the module, it is necessary to drill a small hole, 2-3 mm. Install a valve on both sides of the pipe. Connect 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 the figure Vent.1).
The solar water heater collector works as follows. Valve 1 is closed and we start filling the manifold with water by opening valve 2. Water fills the bottles from the bottom up. The air then escapes from the holes 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 the 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 actually all.
Everything is exactly the same as in a barrel, only such a collector will heat water much more efficiently than a barrel, due to its large area.

A little about the design.
Of course, it is desirable to put the modules in a "box" to stiffen the structure. The bottom of the box is preferably made of 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 polyethylene foam ("foam"). 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, no more.
Firstly, in summer this is the most optimal angle of inclination with respect to the Sun (almost perpendicular), and in winter this collector is not used.
Secondly, it will provide a minimum water pressure drop (water column height), which is important in the presence of many bottle joints. Although during the tests I put my 3-bottle module even vertically and it “held” the pressure at 0.1 atm., I would not risk it during work.

The size of the entire water heater is up to the taste of the creator. For 200 liters you need 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!
You can use the heater in the "poured - poured" mode. Or you can arrange a thermally insulated storage tank for warm water next to it. On a good sunny day, a 2-meter, excuse me, 2-kilowatt water heater will heat you half a ton of water.

Such a water heater is not afraid of frosts (except for water shut-off valves), it is also not afraid of the sun (PET does not decompose well in the sun).
Of course, such a solar water heater has its drawbacks (for example, poor automation), but a lot pays off with its almost free. Judge for yourself what the money will be spent on. Well, a pipe, a couple of valves and 2-3 tubes silicone sealant for 45-50 rubles / piece. And you will get water bottles as a bonus when buying water in the store. By connecting your acquaintances to their collection, you will collect several tens or even hundreds of bottles by the next season and will be able to make yourself a very worthy and productive solar water heater. Total: 300-500 rubles maximum (!!!), and you have hot water for the whole season!
* * *
While experimenting with the elements of a flow-accumulative solar water heater made of plastic PET bottles, I somehow noticed that the temperature of a dark (brown) beer bottle is even to the touch higher than that of a transparent one from under water. This prompted me to do a simple experiment with bottles of different colors and types, in order to identify the most effective ones in terms of heating.
At the very beginning, I believed 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 results of the experiments dispelled my theories to smithereens.

The conditions for the experiment were simple. I just lined up a row of bottles against the wall of the shed, which faces roughly southeast. Since the conditions for all the bottles were exactly the same, I did not thermally insulate and orient them. Those. this is how, in spartan conditions, this used PET container was supposed to show its true character.

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 the IR rays not absorbed by the water and reflect them back into the bottle.

2) Blackening the back of the bottle (with rubber-bitumen mastic from an aerosol can) will allow you to “absorb” the IR rays that have passed through the bottle. One of the bottles was completely blackened, i.e. from all sides and became black and matte.
Everything was done the day before and the next day all the bottles met the dawn at the place of the experiment. The ambient temperature (in the shade nearby) and the wind blowing over the bottles were also taken into account.

The sun that day shone through a small haze, i.e. did not give full heat, 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 holding your hand in it, at least for 2 minutes ... Just stock up on more post-burn ointment ... And at the same time measure the temperature of hot water from the tap in the apartment. It is unlikely to 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 remained the "coldest". Heating can be safely attributed to the non-absolute transparency of the bottle itself, and not to 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 acts as a radiator-cooler.

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

5. Dark plastic bottles also performed very well. This suggests that heat absorption by PET bottles occurs mainly on the side facing the sun. And very weakly - actually the "insides" of the bottle (water). And absolutely nothing - the back side.

This allows us to conclude that what actually 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 or storage heater made of PET bottles will be the most effective. By the way, these same results allow us to estimate the design of the most efficient "classic" water heater. It is quite obvious that its “mirror” does not have to be transparent at all. And if it is transparent, then the “bottom” should be absolutely heat-absorbing.
Now let's talk about the "place" of such a heater in the country hot water supply system.
Of course, the presence of such a heater on the roof does not guarantee that you will have hot water. There are also prolonged bad weather, and at night, especially in the demi-season, the water in such a heater will cool down greatly.

I think that such a water heater performs 2 functions.

A) Allows you to make sure for “mere pennies” that solar water heating is possible and this is a reality. After all, not everyone will decide to build a solar collector like this from the bay, investing in solid money for the sake of the ephemeral saving of electricity, firewood, and money. This water heater for 500 rubles will pay off in a season and will let you feel the charm 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.

The consumption of hot water in each family is different. But in any case, it should always be. Therefore, as soon as the heating of water in the solar collector ends, it should immediately be sent to a well-thermally insulated storage tank, from which hot water is consumed. A heating element should also be installed in the same storage tank, 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 actual solar water heater 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 Methods" Patlakh V.V. 1993-2007

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

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 after a hot day to take a shower before going to bed, and it will not hurt to refresh yourself during the day. But not ice-cold water from a well or a well.

But the independent production of such systems is extremely laborious and expensive, and in general, with an amateurish approach, it promises more trouble than benefit.

In fact, it is necessary to make a hermetic collector, organize the circulation of water and its regular replenishment, avoid mixing already heated water with fresh cold water. And for the winter, the whole thing is drained (we don’t have Greece here with +12 in January). And what for? Toli business native iron barrel! Poured - warmed up, drained for the winter - no problem. So what if it works only 10-15 times a year. But without the hassle.

These are all problems that keep 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 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 from plastic 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 max. And in order to take a decent shower, you need at least 50-60 liters, preferably more than 100.

The main problem of 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 due to solar energy. Taking, for example, 100 such mini-reservoirs, i.e. bottles, we will already get 200 liters of warm water!

Having measured the diameter of the thread on the neck of the bottle, I picked up a drill with which a hole is drilled in the bottom of another bottle. The best fit was a drill - a hole saw for drilling large diameter holes in wood by 26 mm (sets of such files are commercially available in abundance and cost 70-100 rubles). With this diameter, the neck of the bottle is screwed quite tightly into the hole in the bottom of the other. Sometimes you have to work with a large round file. Yes, and it is advisable to pre-drill a hole strictly in the center of the bottle with a conventional 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 - pimples. Therefore, for mass precision drilling, it would be better to make a simple template so that the drill does not scour.

The next issue was sealing. Generally speaking, nothing seems to stick or stick to PET. But it turned out not quite so. Even with the drilled hole, the bottom of the bottle retained absolute rigidity, and this gave hope for the use of silicone sealants. Having carefully degreased the surfaces with acetone, I smeared the threads of the bottle and screwed it into the bottom. And then abundantly smeared the joint with sealant and outside. For reliability, I left the bottles motionless for 3 days (sealant fermentation rate 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 a series connection of only 3 bottles.

The tightness of the joints turned out to be absolute! In the photo, water bottles are on cardboard and, as you can see, no water drips! By the way, silicone is so stuck to PET that 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 superbly even without any additional tricks. Thus, a certain conditional cell of a collector - a water heater was obtained, with dimensions of 0.1 meters (bottle diameter) by 1 meter (bottle length approx. 35 cm). Those. the collector area was 0.1 kiloV. meter, and the capacity is approx. 6 liters. It is easy to calculate that for 1 kiloV. meter will fit about 10 of these 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 only heated - you can boil it! Well, 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 country needs.

Now about the water heater project itself.

To connect all our modules in parallel, you will need a pipe with a sufficiently large diameter (50 millimeters, and preferably 100, for example, polypropylene). All modules crash into it in the same way as the bottles are joined to each other in the module. It might be easier to do it. After gluing or screwing a bottle cap to the pipe with a 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, should be inclined (the bottom side is facing south, the common pipe is at the lowest point of the collector). In the topmost bottle of the module, it is necessary to drill a small hole, 2-3 mm. Install a valve on both sides of the pipe. Connect 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 (vent. 1 in the figure).

The solar water heater collector works as follows. Valve 1 is closed and we start filling the manifold with water by opening valve 2. Water fills the bottles from the bottom up. The air then escapes from the holes 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 the 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 actually all. Everything is exactly the same as in a barrel, only such a collector will heat water much more efficiently than a barrel, due to its large area.

A little about the design.

Of course, it is desirable to put the modules in a "box" to stiffen the structure. The bottom of the box is preferably made of 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 polyethylene foam ("foam"). 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, no more. Firstly, in summer this is the most optimal angle of inclination with respect to the Sun (almost perpendicular), and in winter this collector is not used. Secondly, it will provide a minimum water pressure drop (water column height), which is important in the presence of many bottle joints. Although during the tests I put my 3-bottle module even vertically and it “held” the pressure at 0.1 atm., I would not risk it during work.

The size of the entire water heater is up to the taste of the creator. For 200 liters you need approx. 110 bottles, which will occupy an area of approx. 3 kiloV.meters. True, the power of such a heater will already be about 3 kW!

You can use the heater in the "poured - poured" mode. Or you can arrange a thermally insulated storage tank for warm water next to it. On a good sunny day, a 2-meter, excuse me, 2-kilowatt water heater will heat you half a ton of water.

Such a water heater is not afraid of frosts (except for water shut-off valves), it is also not afraid of the sun (PET does not decompose well in the sun).

Of course, such a solar water heater has its drawbacks (for example, poor automation), but a lot pays off with its almost free. Judge for yourself what the money will be spent on. Well, a pipe, a pair of valves and 2-3 tubes of silicone sealant for 45-50 rubles / piece. And you will get water bottles as a bonus when buying water in the store. By connecting your acquaintances to their collection, you will collect several tens or even hundreds of bottles by the next season and will be able to make yourself a very worthy and productive solar water heater. Total: 300-500 rubles maximum (!!!), and you have hot water for the whole season!

Konstantin Timoshenko, www.delaysam.ru

Alternative renewable energy sources are very popular. In some EU countries, autonomous heating covers more than 50% of energy needs. In the Russian Federation, solar collectors have not yet received widespread. One of the main reasons: the high cost of equipment. For a solar panel from a domestic manufacturer, you will need to pay at least 16-20 thousand rubles. Products of European brands will cost even more, starting from 40-45 thousand rubles.

Making a solar collector with your own hands will be cheaper, at least half. A homemade solar collector will provide enough heat to heat shower water for 3-4 people. For manufacturing you will need Building tools, ingenuity and improvised means.

What can a solar system be made of?

First you need to understand what principle of operation uses a solar water heater. In internal arrangement block contains the following nodes:

frame;
absorber;
heat exchanger, inside which the coolant will circulate;
reflectors to focus the sun's rays.

The factory collector for heating water from the sun works as follows:

Heat absorption - the sun's rays pass through the glass located on top of the case, or through vacuum tubes. The inner absorbent layer in contact with the heat exchanger is coated with a selective paint. When sunlight hits the absorber, a large amount of heat is released, which is collected and used to heat water.
Heat transfer - the absorber is located in close contact with the heat exchanger. The heat accumulated by the absorber and transferred to the heat exchanger heats the liquid moving through the tubes to the coil inside the heat storage tank. The circulation of water in the water heater is carried out in a forced or natural way.
DHW - two principles of hot water heating are used:
1. Direct heating - hot water after heating is simply dumped into a heat-insulated container. In a monoblock solar system, ordinary domestic water is used as a heat carrier.
2. The second option is to provide hot water with a passive water heater according to the principle of indirect heating. The coolant (often antifreeze) is sent under pressure to the heat exchanger of the solar collector. After heating, the heated liquid is fed into the storage tank, inside which a coil is built in (playing the role of a heating element), surrounded by water for the hot water supply system.
  The coolant heats the coil, through which it transfers heat to the water in the tank. When the tap is opened, the heated water from the heat storage tank flows to the tapping point. Feature of the solar system with indirect heating in the ability to work throughout the year.

The principle of operation used in expensive factory solar systems is copied and repeated in self-made collectors.

Working designs of solar water heaters have a similar device. Only made from improvised materials. There are schemes for the production of collectors from:

polycarbonate;
vacuum tubes;
PET bottles;
beer cans;
refrigerator radiator;
copper pipes OK;
HDPE and PVC pipes.

Judging by the schemes, modern "Kulibins" prefer self-made systems with natural circulation, of the thermosyphon type. The peculiarity of the solution is that the storage tank is located at the top point of the hot water supply. Water circulates by gravity in the system and is supplied to the consumer.

Polycarbonate manifold

Made from honeycomb panels with good thermal insulation properties. Thickness of sheets from 4 to 30 mm. The choice of polycarbonate thickness depends on the required heat transfer. The thicker the sheet and the cells in it, the more water the unit will be able to heat.

To make a solar system yourself, in particular a homemade polycarbonate solar water heater, you will need the following materials:

two threaded rods;
propylene corners, the fittings must have an external threaded connection;
PVC plastic pipes: 2 pcs, length 1.5 m, diameter 32;
2 plugs.

Pipes are laid in the body in parallel. Connect to DHW through shut-off valves. A thin incision is made along the pipe into which a polycarbonate sheet can be inserted. Thanks to the thermosyphon principle, water will independently enter the grooves (cells) of the sheet, heat up and go into the storage tank located at the top of the entire heating system. Heat-resistant silicone is used to seal and fix the sheets inserted into the pipe.

To increase the thermal efficiency of the collector from cellular polycarbonate, the sheet is coated with any selective paint. Heating of water after applying a selective coating is accelerated by approximately two times.

Vacuum tube manifold

In this case, it will not be possible to manage exclusively with improvised means. To make a solar collector, you will have to buy vacuum tubes. They are sold by companies involved in the maintenance of solar systems and directly by manufacturers of solar water heaters.

For self-produced it is better to choose flasks with feather rods and a heat-pipe. Tubes are easier to mount and change if necessary.

You also need to purchase a block hub for a vacuum solar collector. When choosing, pay attention to the performance of the node (determined by the number of tubes that can be simultaneously connected to the device). The frame is made independently, assembling a wooden frame. Savings in the manufacture at home, taking into account the purchase of ready-made vacuum tubes, will be at least 50%.

Solar system from plastic bottles

For cooking, you need about 30 pieces. PET bottles. When assembling, it is more convenient to use containers of the same size for 1 or 1.5 liters. On preparatory stage labels are removed from the bottles, the surface is thoroughly washed. In addition to plastic containers, you will need the following:

12 m hose for watering plants, 20 mm in diameter;
8 T-pieces;
2 knees;
roll of teflon film;
2 ball valves.

In the manufacture of solar collectors from plastic bottles, a hole is made at the bottom of the base equal to the diameter of the neck, where a rubber hose or PVC pipe is inserted. The collector is assembled in 5 rows of 6 bottles on each line.

On a clear day, after 15 minutes. the water will heat up to 45°C. Considering high performance It makes sense to connect a solar water heater from plastic bottles to a storage tank of 200 liters. The latter is well insulated to prevent heat loss.

Aluminum beer can collector

Aluminum has good thermal characteristics. Not surprisingly, metal is used to make heating radiators.

Aluminum cans can be used in the manufacture of homemade solar systems. Cans made of tin and any other metal are not suitable for production.

For one solar panel, the following components will be required:

jars, about 15 pcs. per line, the body fits 10-15 rows;
heat exchanger - a collector is used from a rubber hose, or plastic pipes;
glue for gluing cans together;
selective paint.

The surface of the cans is painted in dark color. The box is covered with thick glass or polycarbonate.

solar collector from aluminum cans often made for air heating. When using a water coolant, the thermal efficiency of the device decreases.

Solar system from the refrigerator

Another popular solution requiring minimal cost time and money. The solar collector is made from the radiator of an old refrigerator. The coil is already painted black. It is enough just to lay the grate in a wooden case with insulation and connect it to the hot water supply using soldering.

There is a manufacturing option from an air conditioner condenser. To do this, several radiators are connected to a single network. If there is an opportunity to purchase cheap about 8 pcs. capacitors, making a collector is quite possible.

Collector made of copper pipes

Copper has good thermal properties. In the manufacture of a copper solar collector, use:

pipes with a diameter of 1 1/4", used in the installation of heating and hot water systems;
1/4" pipes used in air conditioning systems;
gas-burner;
solder and flux.

The body of the radiator grill is assembled from copper pipes with a large diameter. Holes equal to 1/4 "are drilled in the surface. Pipes of the appropriate diameter are inserted into the grooves obtained. The radiator is covered with glass or polycarbonate. Copper is painted with selective paint.

Solar boiler made of HDPE pipes and PVC hoses

In the production of solar systems, almost any available material is used. There are solutions that allow you to make a collector from a corrugated hose, a rubber hose used for watering plants.

From metal-plastic pipe solar systems are not made due to rubber seals fittings that cannot withstand high heat. With intense solar radiation, the heating in the collector reaches 300°C. When overheated, the seals will definitely leak.

It is possible to manufacture a solar collector from corrugated stainless pipe. The popularity of the solution is due to the speed and ease of installation. The stainless steel corrugated pipe is laid in rings or a snake. The disadvantage is the relative high cost of stainless corrugated pipes.

Despite existing options described above, the most popular are solar collectors made of propylene and HDPE pipes. Each option has its own advantages:

Solar collector from HDPE pipes- for the manufacture choose a material that is resistant to heat. A large number of fittings are sold to facilitate the assembly of a heat storage radiator. Polyethylene pipes low pressure initially have a black or dark blue color, so they do not require staining.
PVC Solar Collector- the popularity of the solution in the ease of installation of the structure, carried out by soldering. The presence of a large number of corners, tees, American women and other fittings facilitates the assembly process. Using soldering, you can create a collector heat exchanger of any configuration.

Production of a solar hot water collector from PEX pipe:

All the described pipes with varying efficiency are used as a core in the manufacture of a home-made solar collector from plastic bottles and aluminum cans.

How to make selective coating

The high efficiency collector has a high degree of absorption of solar energy. The rays fall on a dark surface, after which they heat it. The less radiation is repelled from the absorber of the solar collector, the more heat remains in the solar system.

To ensure sufficient heat storage, it is necessary to create selective coating. There are several production options:

Homemade selective collector coating- use any black paint that, after drying, leaves a matte surface. There are solutions when an opaque dark oilcloth is used as a collector absorber. Black enamel is applied to the heat exchanger pipes, the surface of cans and bottles, with a matte effect.
Special absorbent coatings- you can go the other way by purchasing a special selective paint for the collector. The composition of selective coatings includes polymeric plasticizers and additives that provide good adhesion, heat resistance and a high degree of absorption of sunlight.

Solar systems used exclusively for heating water in the summer may well get by with painting the absorber black with regular paint. Homemade solar collectors for heating a house in winter should have a high-quality selective coating. You can't skimp on paint.

Homemade or factory solar system - which is better

Make at home a solar collector capable of technical specifications and indicators to compare with factory products is unrealistic. On the other hand, if you just want to provide enough water for summer shower, solar energy will be enough to operate a simple home-made water heater.

As for liquid collectors operating in winter, not even all factory solar systems can work with low temperatures. All-weather systems, these are most often devices with vacuum heat pipes, with increased efficiency capable of operating down to -50°C.

Factory solar collectors are often equipped with a rotary mechanism that automatically adjusts the angle of inclination and direction of the panel to the cardinal points, depending on the location of the Sun.

An efficient solar water heater is one that is fully consistent with the tasks assigned to it. To heat water for 2-3 people in the summer, you can get by with an ordinary solar collector made with your own hands from improvised means. For heating in winter, despite the initial costs, it is better to install a factory solar system.