Various solar collectors have appeared on the market for a long time. These are devices that use solar energy to heat water for household needs. But their high cost prevents them from gaining popularity among users; this is the problem with all alternative energy sources. For example, the total cost of purchasing and installing an installation that will meet the needs of an average family will be $5,000. But there is a way out: you can make a solar collector with your own hands from affordable materials. How to implement this will be discussed in this material.

How does a solar collector work?

The principle of operation of the collector is based on the absorption (absorption) of the thermal energy of the sun by a special receiving device and transferring it to the coolant with minimal losses. Copper or glass tubes painted black are used as a receiver.

After all, it is known that objects that are dark or black in color absorb heat best. The coolant is most often water, sometimes air. By design, solar collectors for home heating and hot water supply are of the following types:

• air;
• water flat;
• water vacuum.

Among others, the airborne solar collector is distinguished by its simplicity of design and, accordingly, the lowest price. It is a panel - a solar radiation receiver made of metal, enclosed in a sealed housing. For better heat transfer, the steel sheet is equipped with ribs on the back side and laid on the bottom with thermal insulation. There is clear glass installed in front, and on the sides of the case there are openings with flanges for connecting air ducts or other panels, as shown in the diagram:

The air entering through the opening on one side passes between the steel ribs and, having received heat from them, exits on the other.

It must be said that the installation of solar collectors with air heating has its own characteristics. Due to their low efficiency, several similar panels combined into a battery must be used to heat rooms. In addition, you will definitely need a fan, since the heated air from the collectors located on the roof will not go down on its own. The schematic diagram of the air system is shown below in the figure:

The simple device and principle of operation allow you to make air-type manifolds with your own hands. But you will need a lot of material for several collectors, and you still won’t be able to heat the water with their help. For these reasons, home craftsmen prefer to work with water heaters.

Flat-plate collector design

For self-production, flat solar collectors designed for heating water are of greatest interest. A rectangular-shaped metal or aluminum alloy housing houses a heat receiver - a plate with a copper tube coil pressed into it. The receiver is made of aluminum or copper coated with a black absorption layer. As in the previous version, the bottom of the plate is separated from the bottom by a layer of heat-insulating material, and the role of the lid is played by durable glass or polycarbonate. The figure below shows the structure of a solar collector:

The black plate absorbs heat and transfers it to the coolant moving through the tubes (water or antifreeze). Glass performs 2 functions: it transmits solar radiation to the heat exchanger and serves as protection from precipitation and wind, which reduce the performance of the heater. All connections are made hermetically so that dust does not get inside and the glass does not lose its transparency. Again, the heat of the sun's rays should not be ventilated by the outside air through the cracks; the efficient operation of the solar collector depends on this.

This type is the most popular among buyers because of the optimal price-quality ratio, and among home craftsmen because of its relatively simple design. But such a collector can be used for heating only in the southern regions; as the outside air temperature drops, its performance drops significantly due to high heat losses through the housing.

Vacuum manifold device

Another type of solar water heaters is manufactured using modern technologies and advanced technical solutions, and therefore belongs to a high price category. There are two such solutions implemented in the collector:

• thermal insulation using vacuum;
• using the energy of vaporization and condensation of a substance boiling at a low temperature.

The ideal option to protect the collector absorber from heat loss is to enclose it in a vacuum. A copper tube filled with refrigerant and covered with an absorbent layer is placed inside a flask made of durable glass, the air from the space between them is pumped out. The ends of the copper tube fit into the pipe through which the coolant flows. What happens: the refrigerant boils under the influence of sunlight and turns into steam, it rises up the tube and, from contact with the coolant through a thin wall, turns into a liquid again. The working diagram of the collector is shown below:

The trick is that in the process of turning into steam, the substance absorbs much more thermal energy than during normal heating. The specific heat of vaporization of any liquid is higher than its specific heat capacity, and therefore vacuum solar collectors are very effective. Condensing in a pipe with a flowing coolant, the refrigerant transfers all the heat to it, and itself flows down for a new portion of the sun's energy.

Thanks to their design, vacuum heaters are not afraid of low temperatures and remain operational even in the cold, and therefore can be used in northern regions. The intensity of water heating in this case is lower than in summer, since in winter less heat from the sun reaches the ground, and clouds often interfere. It is clear that making a glass flask with evacuated air at home is simply unrealistic.

Note. There are vacuum tubes for the collector that are filled directly with coolant. Their disadvantage is that they are connected in series; if one bulb fails, the entire water heater will have to be replaced.

How to make a solar collector?

Before you start work, you should decide on the dimensions of the future water heating apparatus. It is not easy to accurately calculate the heat exchange area; much depends on the intensity of solar radiation in a given region, the location of the house, the material of the heating circuit, and so on. It would be correct to say that the larger the thermal collector, the better. However, its size is probably limited by the place where it is planned to be installed. This means that we must proceed from the area of ​​this place.

The easiest way to make a body is from wood, laying a layer of foam or mineral wool on the bottom. It is also convenient for this purpose to use the sashes of old wooden windows, where at least one glass has been preserved. The choice of material for the heat receiver is unexpectedly wide, which is what craftsmen do not use to assemble the collector. Here is a list of popular options:

• thin-walled copper tubes;
• various polymer pipes with thin walls, preferably black. A polyethylene PEX pipe for water supply works well;
• aluminum tubes. True, connecting them is more difficult than copper ones;
• steel panel radiators;
• black garden hose.

Note. In addition to those listed, there are many exotic versions. For example, an air solar collector made from beer cans or plastic bottles. Such prototypes are distinguished by their originality, but require a significant investment of labor with dubious returns.

A metal sheet covering the entire area of ​​the future heater must be placed in an assembled wooden case or an old window sash with an attached bottom and laid insulation. It's good if you can find a sheet of aluminum, but thin steel will do. It must be painted black, and then the pipes must be laid in the form of a coil.

Without a doubt, the collector for heating water is best made from copper pipes; they transfer heat well and will last for many years. The coil is tightly attached to the metal screen with brackets or any other available method; 2 fittings for water supply are led out.

Since this is a flat and not a vacuum collector, the heat absorber must be covered on top with a translucent structure - glass or polycarbonate. The latter is easier to process and more reliable in operation; it will not break from hail impacts.

After assembly, the solar collector must be installed in place and connected to the water storage tank. When installation conditions allow, it is possible to organize natural circulation of water between the tank and the heater, otherwise a circulation pump is included in the system.

Conclusion

Heating your home with DIY solar collectors is an attractive prospect for many homeowners. For residents of the southern regions, this option is more accessible; they just have to fill the system with antifreeze and properly insulate the body. In the north, a homemade collector will help heat water for household needs, but it will not be enough to heat a house. The cold and short daylight hours take their toll.

Alternative sources of renewable energy are extremely popular. In some EU countries, autonomous heating supplies cover more than 50% of energy needs. In the Russian Federation, solar collectors have not yet become 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 from European brands will cost even more, starting from 40-45 thousand rubles.

Making a solar collector with your own hands will be at least half cheaper. A homemade solar collector will provide enough heat to heat shower water for 3-4 people. To make it you will need construction tools, ingenuity and available materials.

What can a solar system be made from?

First, you need to understand what operating principle a solar water heater uses. The internal structure of the block contains the following components:

• frame;
• absorber;
• a heat exchanger within which the coolant will circulate;
• reflectors to focus the sun's rays.

The factory solar water heating collector works as follows:

• Heat absorption - the sun's rays pass through the glass located on top of the body or through vacuum tubes. The internal absorbent layer in contact with the heat exchanger is painted with 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. Water circulation in the water heater is carried out by forced or natural means.
• DHW - two principles of heating hot water are used:
  1. Direct heating - hot water after heating is simply discharged into a thermally insulated container. In a monoblock solar system, ordinary household water is used as a coolant.
  2. The second option is to provide hot water supply with a passive water heater based on the principle of indirect heating. The coolant (often antifreeze) is sent under pressure to the solar collector heat exchanger. After heating, the heated liquid is supplied to a storage tank, inside of which a coil (playing the role of a heating element) is built, surrounded by water for the hot water supply system.
     The coolant heats up the coil, thereby transferring heat to the water in the container. When the tap is opened, heated water from the heat-storing tank flows to the water collection point. The peculiarity of a solar system with indirect heating is its ability to operate throughout the year.

The operating principle used in expensive factory-made solar systems is copied and repeated in do-it-yourself collectors.

The working designs of solar water heaters have a similar structure. They are only made from scrap materials. There are schemes for the production of collectors from:

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

Judging by the diagrams, modern “Kulibins” prefer homemade systems with natural circulation, thermosiphon type. The peculiarity of the solution is that the storage tank is located at the top point of the hot water supply system. Water circulates through the system by gravity and is supplied to the consumer.

Polycarbonate manifold

They are made from honeycomb panels with good thermal insulation properties. Sheet thickness 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 installation can heat.

To make a solar system yourself, in particular a homemade solar water heater made of polycarbonate, 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.

The pipes are laid parallel to the housing. Connect to the hot water supply via shut-off valves. A thin cut is made along the pipe into which a sheet of polycarbonate can be inserted. Thanks to the thermosiphon principle, water will independently flow into the grooves (cells) of the sheet, heat up and go into the storage tank located at the top of the entire heating system. To seal and fix the sheets inserted into the pipe, thermally resistant silicone is used.

To increase the thermal efficiency of a cellular polycarbonate collector, the sheet is coated with any selective paint. Heating of water after applying selective coating accelerates approximately twice.

Vacuum tube manifold

In this case, it will not be possible to get by solely 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 independent production, it is better to choose flasks with feather rods and a heat-pipe thermal channel. The tubes are easier to install and change if necessary.

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

Solar system made from plastic bottles

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

• 12 m of hose for watering plants, diameter 20 mm;
• 8 T-adapters;
• 2 knees;
• roll of Teflon film;
• 2 ball valves.

When making solar collectors from plastic bottles, a hole is made at the bottom of the base equal to the diameter of the neck, into which 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, within 15 minutes. the water will heat up to a temperature of 45°C. Considering the high performance, it makes sense to connect a solar water heater made 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. It is not surprising that metal is used to make heating radiators.

Aluminum cans can be used in the manufacture of homemade solar systems. Cans made of tin or 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 accommodates 10-15 rows;
• heat exchanger - a collector made of a rubber hose or plastic pipes is used;
• glue for gluing cans together;
• selective paint.

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

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

Solar system from the refrigerator

Another popular solution that requires minimal 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 place the grille in a wooden case with insulation and connect it to the hot water supply using soldering.

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

Copper tube collector

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

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

The radiator grille body is assembled from copper pipes with a large diameter. Holes equal to 1/4" are drilled into the surface. Pipes of the appropriate diameter are inserted into the resulting grooves. The radiator is covered with glass or polycarbonate. The 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 corrugated hose, a rubber hose used for watering plants.

Solar systems are not made from metal-plastic pipes due to rubber fitting seals that cannot withstand strong heat. With intense solar radiation, heating in the collector reaches 300°C. If overheated, the gaskets 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. Corrugated stainless steel pipe is laid in rings or snakes. The disadvantage is the relative high cost of stainless corrugated pipes.

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

• Solar collector made of HDPE pipes- for manufacturing, choose a material that is resistant to heat. A large number of fittings are sold to facilitate the assembly of a heat storage radiator. Pipes made of low-density polyethylene are initially black or dark blue in color, so they do not require painting.
• Solar collector made of PVC pipes- the popularity of the solution lies in the ease of installation of the structure, carried out using soldering. The presence of a large number of angles, tees, American females and other fittings facilitates the assembly process. Using soldering, you can create a collector heat exchanger of any configuration.

Making a solar hot water collector from PEX pipe:

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

How to make selective coating

A highly efficient collector has a high degree of solar energy absorption. The rays hit a dark surface and then heat it up. The less radiation is repelled from the solar collector absorber, the more heat remains in the solar system.

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

• Homemade selective collector coating- use any black paints that leave a matte surface after drying. 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. Selective paints and varnishes contain polymer 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 summer can easily get by by painting the absorber black using regular paint. Homemade solar collectors for heating a house in winter must have a high-quality selective coating. You can't skimp on paint.

Homemade or factory solar system - which is better?

It is unrealistic to make a solar collector at home that can be compared with factory products in terms of technical characteristics and performance. On the other hand, if you simply need to provide enough water for a summer shower, solar energy will be enough to operate a simple homemade water heater.

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

Factory solar collectors are often equipped with a rotating 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 effective solar water heater is one that fully meets its intended purpose. 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 materials. For heating in winter, despite the initial costs, it is better to install a factory solar system.

Video course on making a panel solar water heater

The concept of an energy efficient home involves the creation, implementation and operation of renewable energy sources. Do-it-yourself solar collectors, which were extremely rare not so long ago, have become increasingly common.

The constant improvement of solar systems and a significant drop in prices for them have led to their even greater appearance in everyday life. The cost of factory models today is comparable to the costs required to install a classic heating system. However, anyone can do this technology on their own.

The principle of operation of the solar collector

To briefly describe the principle of operation of the collector, it is necessary to capture solar thermal energy. Subsequently, it is concentrated and used by humans.

The collector system consists of the following components:

• Thermal accumulator (regular container for liquid)
• Heat exchange circuit
• Directly collector

Liquid or gaseous coolant circulates through the collector. The resulting energy heats it and, through a mounted storage tank, transfers heat to the water.

The heated liquid is stored in the tank until it is used. The scope of its application is very wide - from ordinary household needs to home heating. To prevent the water from cooling quickly, it is necessary to properly insulate the container.

Water circulation in the collector is done in one of two ways: or forced. An additional element that heats the liquid can be mounted in the storage tank, which will turn on when low ambient temperatures are reached and maintain the water temperature, for example, in winter, when the solstice is short.

Introductory video about the design of a water heater

Types of solar collectors

When planning to install a solar collector with your own hands in the house, you need to decide on the type of design:

Models in which air is the coolant are used extremely rarely. This is due to the properties of the liquid - it conducts heat much better than gas. Air collectors are often made flat in shape so that the air, in contact with the absorption device, naturally heats up.

air solar collector diagram

Vacuum solar collectors

Vacuum models are the most complex. Instead of a box that is covered with glass, it uses large glass tubes. Inside them there are tubes with a smaller diameter, which contain an absorber that collects thermal energy. There is a vacuum between the tubes, it acts as a heat insulator.

Flat-plate solar collectors

The most common is a flat solar collector, inside of which there is a special absorbent layer placed in a glass box. It is connected to tubes through which the coolant liquid (usually propylene glycol) moves.

flat solar collector diagram

But when deciding to make a solar collector with your own hands, you need to understand that it is impossible to make such complex devices, similar to industrial ones. In addition, their efficiency will be significantly lower, their service life will be shorter, but so will their material investments.

Structural drawings

Let's get started

Before building a solar collector, it is necessary to make the appropriate calculations and determine how much energy it should produce. But you shouldn’t expect high efficiency from a homemade installation. Having determined that there will be enough of it, you can begin.

The work can be divided into several main stages:

1. Make a box
2. Make a radiator or heat exchanger
3. Make a front camera and storage device
4. Assemble the collector

To make a box for a solar collector with your own hands, you should prepare an edged board of thickness 25-35 mm and width 100-130 mm. Its bottom should be made of textolite, equipped with ribs. It should also be well insulated using polystyrene foam (but preference is given to mineral wool), covered with a galvanized sheet.

Having prepared the box, it’s time to make the heat exchanger. You should follow the instructions:

1. It is necessary to prepare 15 thin-walled metal tubes 160 cm long and two inch pipes 70 cm long
2. In both thickened tubes, holes are drilled with the diameter of the smaller tubes into which they will be installed. In this case, you need to ensure that they are coaxial on one side, the maximum step between them is 4.5 cm
3. The next stage is that all the tubes need to be assembled into a single structure and welded securely
4. The heat exchanger is mounted on a galvanized sheet (previously attached to the box) and fixed with steel clamps (metal clamps can be made)
5. It is recommended to paint the bottom of the box in a dark color (for example, black) - it will better absorb solar heat, but to reduce heat loss, the external elements are painted white
6. To complete the installation of the collector, it is necessary to install a cover glass near the walls, while not forgetting about reliable sealing of the joints
7. A distance of 10-12 mm is left between the tubes and the glass

All that remains is to build a storage tank for the solar collector. Its role can be played by a sealed container, the volume of which varies about 150-400 l. If you cannot find one such barrel, you can weld several small ones together.

Like the collector, the storage tank is thoroughly insulated from heat loss. All that remains is to make a fore-chamber - a small vessel with a volume of 35-40 liters. It must be equipped with a water-falling device (a swivel valve).

The most responsible and important stage remains - to assemble the collector together. You can do it this way:

1. First you need to install the front camera and storage. It is necessary to ensure that the liquid level in the latter is 0.8 m lower than in the front chamber. Since a lot of water can accumulate in such devices, it is necessary to think about how they will be reliably shut off
2. The collector is placed on the roof of the house. Based on practice, it is recommended to do this on the south side, tilting the installation at an angle of 35-40 degrees to the horizontal
3. But you need to take into account that the distance between the storage tank and the heat exchanger should not exceed 0.5-0.7 m, otherwise the losses will be too significant
4. At the end, the following sequence should be obtained: the front camera must be located above the drive, the latter - above the collector

The most important stage is coming - it is necessary to connect all the components together and connect the water supply network to the finished system. To do this, you will need to visit a plumbing store and purchase the necessary fittings, adapters, sockets and other shut-off valves. It is recommended to connect high-pressure sections with a pipe with a diameter of 0.5 inches, low-pressure sections with a diameter of 1 inch.

Commissioning is carried out as follows:

1. The unit is filled with water through the bottom drainage hole
2. The anterior chamber is connected and the fluid levels are adjusted
3. It is necessary to walk along the system and check that there are no leaks
4. Everything is ready for everyday use

Solar collector from a refrigerator coil

You can make a solar collector with your own hands from an ordinary coil taken from an old refrigerator. To work you will need to prepare:

1. Directly coil
2. Slats and foil for the frame
3. Barrel or water tank
4. Rubber mat
5. Shut-off valves (valves, pipes, etc.)
6. Glass

After washing the coil of freon, you need to knock down the rack frame around it. Its exact dimensions will depend on the size of the working unit that was removed from the refrigerator. The rug must be adjusted to the slats, among which the coil must be positioned freely.

A foil layer is placed on the rubber mat (bottom of the frame). Then the coil is fixed using screw clamps. Holes are made in the walls through which pipes will pass. Productivity can be increased by sealing joints with sealants.

The bottom is also reinforced with slats. Glass is mounted on top and secured with tape. To avoid worry, you can cut out several aluminum plates and make clamps from them.

Video about the technical design and testing of the solar collector:

In custody

A structure such as a do-it-yourself solar collector can significantly increase the level of comfort in a country house or country house. Although insignificant, it reduces the cost of consumed energy generated by classical energy sources.

It has always been a dream to use solar energy for domestic needs. This idea began to develop especially urgently in the last fifty years, when new materials appeared that made it possible to construct quite effective structures. Tools have also appeared that can be used to make complex technological structures at home.

The idea of ​​heating water with the help of the sun was implemented in ancient times. Ordinary barrels exposed to the sun or shade absorbed heat flow from the environment for a certain time. The temperature of the liquid increased with increasing solar radiation intensity.

In the seventies and eighties of the 19th century, Joseph Stefan and Ludwig Boltzmann discovered the law of thermal radiation. They derived calculation formulas on the basis of which the heat flow received from the Sun on the surface of the Earth is determined. For objects located on Earth, use the following formula:

Where σ = 5.670367·10 -4, W/(m 2 ·K 4) ​​– Stefan-Boltzmann constant;

F – heat absorption surface area, m2;

C 2 – degree of emissivity of the heat perception surface;

T 1 is the temperature of the thermal emitter; for the surface of the Sun it is generally accepted that it is T 1 = 6000 K;

T 2 – temperature of the heat sink – this is the surface heated by solar radiation, (T 2 = t 2 + 273), K;

where t 2 is the temperature of the heat sink (body on Earth), °C;

ϕ – angle of incidence of solar rays, °.

What is a collector and the purpose of solar collectors

A solar collector is a device that collects radiation energy and then transfers the accumulated heat to consumers. In practice, another term is used - solar collector.

According to their intended purpose, solar installations (solar installations) are divided into:

• solar concentrators are devices that collect solar energy into a narrow stream. They are used for melting metal. At the NPO Physics-Sun Institute (Tashkent), melting furnaces were developed and manufactured in which temperatures of more than 5000...5500 °C were achieved;
• solar panels – devices for converting radiation from the Sun into electrical energy;
• solar desalination plants - machines designed to produce fresh water from water with a high content of mineral salts;
• solar dryers are thermal devices that remove moisture from vegetables and fruits using solar energy;
• solar heaters (air solar collector) – installations for transferring heat flow from infrared radiation to coolants.

How does a solar collector work?

In addition to visible light, solar radiation also has an invisible infrared spectrum. It is he who transfers thermal energy. Based on research, it has been established that in the temperate climate zone the intensity of thermal radiation at noon reaches more than 5 kW/m2. In Fig. Figure 1 shows the dependence of total insolation for 48° north latitude.

Rice. 1 Total insolation of solar radiation for different periods of the temperate zone of Europe

Food for thought! Thermal radiation is divided into: direct and diffuse. Therefore, even on a cloudy day, the flow of solar heat flow is felt. From the presented illustration it is clear that the amount of incoming heat in the summer and winter periods has significant differences. Therefore, when designing devices, possible efficiency is taken into account, taking into account costs.

The schematic diagram of the solar collector is shown in Fig. 2. Solar radiation enters the collector through a translucent fence. The receiving panel, painted black, absorbs heat. As a result, the black body heats up. The subsequent heat transfer process occurs by convection. Heat is transferred from the heated wall to the flow of liquid (gas) moving through the pipelines. The moving medium heats up.

Attention! To prevent heat losses, the collector enclosure is thermally insulated. Since the heat received inside is used to heat the flow, the intensity of the reflected radiation from the panel receiving the radiation is low.

The rise in cost of traditional energy sources encourages private home owners to look for alternative options for heating their homes and heating water. Agree, the financial component of the issue will play an important role when choosing a heating system.

One of the most promising methods of energy supply is the conversion of solar radiation. For this purpose, solar systems are used. Understanding the principle of their design and the mechanism of operation, making a solar collector for heating with your own hands will not be difficult.

We will tell you about the design features of solar systems, offer a simple assembly diagram and describe the materials that can be used. The stages of work are accompanied by visual photographs, the material is supplemented by videos about the creation and commissioning of a home-made collector.

Modern solar systems are one of the sources of heat. They are used as auxiliary heating equipment that converts solar radiation into energy useful to home owners.

They are able to fully provide hot water supply and heating during the cold season only in the southern regions. And only if they occupy a sufficiently large area and are installed in open areas not shaded by trees.

Despite the large number of varieties, their operating principle is the same. Any one is a circuit with a sequential arrangement of devices that supply thermal energy and transmit it to the consumer.

The main working elements are solar collectors. The technology on photographic plates is somewhat more complicated than that of a tubular collector.

In this article we will look at the second option – a solar collector system.

Solar collectors still serve as auxiliary energy suppliers. It is dangerous to completely switch home heating to a solar system due to the inability to predict a clear number of sunny days

Collectors are a system of tubes connected in series to the output and input lines or laid out in the form of a coil. Process water, air flow, or a mixture of water and some kind of non-freezing liquid circulates through the tubes.

Circulation is stimulated by physical phenomena: evaporation, changes in pressure and density from the transition from one state of aggregation to another, etc.

The collection and accumulation of solar energy is carried out by absorbers. This is either a solid metal plate with a blackened outer surface, or a system of individual plates attached to tubes.

For the manufacture of the upper part of the body, the lid, materials with a high ability to transmit light are used. This can be plexiglass, similar polymer materials, tempered types of traditional glass.

In order to eliminate energy loss, thermal insulation is placed in the box on the back side of the device

It must be said that polymer materials do not tolerate the influence of ultraviolet rays quite well. All types of plastic have a fairly high coefficient of thermal expansion, which often leads to depressurization of the housing. Therefore, the use of such materials for the manufacture of the collector body should be limited.

Water as a coolant can only be used in systems designed to supply additional heat in the autumn/spring period. If you plan to use the solar system all year round, before the first cold snap, change the process water to a mixture of it and antifreeze.

If a solar collector is installed to heat a small building that has no connection with the autonomous heating of the cottage or with centralized networks, a simple single-circuit system with a heating device at the beginning is constructed.

The chain does not include circulation pumps and heating devices. The scheme is extremely simple, but it can only work in sunny summers.

When a collector is included in a double-circuit technical structure, everything is much more complicated, but the range of days suitable for use is significantly increased. The collector processes only one circuit. The predominant load is placed on the main heating unit, running on electricity or any type of fuel.

Home craftsmen have invented a cheaper option - a spiral heat exchanger made of.

An interesting budget solution is a solar system absorber made of a flexible polymer pipe. Suitable fittings are used to connect to the devices at the inlet and outlet. The choice of available materials from which a solar collector heat exchanger can be made is quite wide. This could be the heat exchanger of an old refrigerator, polyethylene water pipes, steel panel radiators, etc.

An important criterion for efficiency is the thermal conductivity of the material from which the heat exchanger is made.

For self-production, copper is the best option. It has a thermal conductivity of 394 W/m². For aluminum, this parameter varies from 202 to 236 W/m².

However, the large difference in thermal conductivity parameters between copper and polypropylene pipes does not mean that a heat exchanger with copper pipes will produce hundreds of times larger volumes of hot water.

Under equal conditions, the performance of a heat exchanger made of copper pipes will be 20% more efficient than the performance of metal-plastic options. So heat exchangers made from polymer pipes have a right to life. In addition, such options will be much cheaper.

Regardless of the material of the pipes, all connections, both welded and threaded, must be sealed. The pipes can be placed either parallel to each other or in the form of a coil.

The coil-type circuit reduces the number of connections - this reduces the likelihood of leaks and ensures a more uniform flow of coolant.

The top of the box in which the heat exchanger is located is covered with glass. As an alternative, you can use modern materials, such as an acrylic analogue or monolithic polycarbonate. The translucent material may not be smooth, but grooved or matte.

Conclusions and useful video on the topic

Manufacturing process of a basic solar collector:

How to assemble and commission a solar system:

Naturally, a self-made solar collector will not be able to compete with industrial models. Using available materials, it is quite difficult to achieve the high efficiency that industrial designs have. But the financial costs will be much lower compared to purchasing ready-made installations.