Hot water in a country house or in a private house is a desirable luxury, which not everyone can boast of until now. Fortunately, you can create a solar water heater with your own hands at a minimum cost, which will provide the necessary amount of hot water and at the same time be free to operate. A nice bonus is the environmental friendliness of such equipment.

What is a solar water heater?

For solar water heaters, there has long been a term - a solar collector. But since such factory-made equipment costs around $ 300-400, it has not gained distribution and is used only by a few. However, almost everyone can make a solar heater. At the same time, the size of the savings is colossal, a home-made device will cost 10 times less.

The principle of operation of a solar water heater is incredibly simple: its dark (preferably black) surface heats up, that is, it absorbs heat and then gives it to water. Most often, such structures are used in summer showers, and are also installed on the roofs of houses, brought to the washstand in the kitchen or to the bathroom, if any.

It is noteworthy that the operation of a home-made solar collector does not require a pump, it is not powered from the electrical network, that is, it is completely autonomous. To heat water, only the presence of the sun is necessary, and in Russia it regularly shines brightly for 5-7 months a year. Even in winter, a homemade solar panel can heat water well.

The factory collector is a rectangular black plate with a plastic or glass surface, inside of which there is a metal plate (flat collector) or a heat exchanger - metal / plastic tubes with liquid (liquid collector). Since we need a water heater, the latter option is ideal, and we will consider exactly how it is made.

Using a solar water heater, you can heat the water in the tank up to 50 degrees, and this is more than enough for washing dishes or hygiene procedures.

Solar water heater design

The structure of a solar water heater is incredibly simple:

• frame (body);
• absorber (absorber);
• heat exchanger;
• glass.

To clarify, with the correct installation of a solar water heater, there is no need to use a pump. The movement of water is due to convection. The warm liquid itself rises up the system, giving way to cold water from the tank.

Creating a housing for a water heater

In fairness, we clarify that the presence of a housing is, in principle, not necessary if the water heater is supposed to be installed in one specific place forever. But since nothing is eternal, and in different periods of the year it is required to install the solar collector at different angles so that its surface is perpendicular to the sun's rays, it is better to create a model with a body. It doesn't take much effort, and the benefits will be greater.
If the farm has an unnecessary window frame - it is a ready-made case for a solar water heater. If there is no frame, you can quickly make it yourself.


The first thing you need to decide is the size of the case. There are many options, but most often the width is 40-80 cm, and the height is 60-200 cm. But you can choose any other parameters that are better suited to the intended conditions of use.

The frame is conveniently made of plastic, metal or wood. Everything that is at hand will fit. At the same time, the height of the profile should be 3-6 cm, so that there is enough space inside to fix the heat exchanger.

When the frame is ready, the bottom is attached to it: a sheet of metal, plastic, plywood, etc. to choose from.

Creating an absorber

The absorber or absorber is essentially the bottom of our case. It has two tasks: to hold the heat exchanger in place and to absorb solar heat. In order for the absorption task to be performed better, it is worth doing the following actions:

• lay a layer of heat-insulating material on the bottom;
• lay a galvanized sheet on the thermal insulation (copper sheet is better, but it is much more expensive);
• paint the metal with a matt black paint for the best heat absorption.

When the paint dries, we proceed to the creation of a heat exchanger.

Heat exchanger options for solar water heater

There are several options for heat exchangers when creating a solar collector:

• copper (metal) radiator;
• "snake" from a plastic pipe;
• cellular polypropylene with longitudinal cells.

The highest efficiency has a copper radiator, consisting of two copper pipes of an inch diameter, between which there are many pipes of a smaller diameter parallel to each other (like a ladder).

But such a heat exchanger has many disadvantages: the high cost of copper, the complexity of creation (you have to solder all the tubes yourself or pay for the work of a welder).

To create a heat exchanger made of polypropylene, an extruder is needed, so in the end the product will also be expensive.

Therefore, for domestic use, it is much more convenient to use a black plastic or metal-plastic pipe 1/2 inch in diameter. PEX or PEX-Al-PEX-pipe is laid in a "snake" along the absorber, secured with brackets. This lock-in installation can be done in just a few minutes.

The ends of the pipes are brought out of the body, they are equipped with couplings, with the help of which they will be connected to the pipes leading to the tank.

The level of development of modern technologies and materials is so high that not using solar energy is unreasonable from the financial side and criminal in relation to the environment. Unfortunately, the purchase of industrial installations for generating electricity and heat is irrational due to their high cost. Nevertheless, there is a way out: to make a productive solar collector with your own hands from materials that can be found in the nearest hardware store.

The purpose of the solar collector, its advantages and disadvantages

A solar water heater (liquid solar collector) is a device that heats a coolant with the help of solar energy. It is used for space heating, hot water supply, water heating in swimming pools, etc.

The solar collector will provide the house with hot water and heat

The prerequisite for using an eco-friendly water heater is the fact that solar radiation falls on the Earth all year round, although it differs in intensity in winter and summer. So, for middle latitudes, the daily amount of energy in the cold season reaches 1–3 kWh per 1 sq.m, while in the period from March to October this value varies from 4 to 8 kWh/m 2. If we talk about the southern regions, then the figures can be safely increased by 20-40%.

As you can see, the efficiency of the installation depends on the region, but even in the north of our country, the solar collector will provide the need for hot water - the main thing is that there are fewer clouds in the sky. If we talk about the middle lane and the southern regions, then the solar-powered installation will be able to replace the boiler and cover the needs of the heating system coolant in winter. Of course, we are talking about productive water heaters of several tens of square meters.

A solar battery will help save money from the family budget. The following material will help to make it yourself:

Table: distribution of solar energy by region

Average daily amount of solar radiation, kW * h / m 2
Murmansk	Arkhangelsk	Saint Petersburg	Moscow	Novosibirsk	Ulan-Ude	Khabarovsk	Rostov-on-Don	Sochi	Nakhodka
2,19	2,29	2,60	2,72	2,91	3,47	3,69	3,45	4,00	3,99
Average daily amount of solar radiation in December, kW*h/m2
0	0,05	0,17	0,33	0,62	0,97	1,29	1,00	1,25	2,04
Average daily amount of solar radiation in June, kW*h/m2
5,14	5,51	5,78	5,56	5,48	5,72	5,94	5,76	6,75	5,12

Home-built solar collectors are no match for factory-made solar collectors, but a home-made solar installation will cut domestic water heating costs and save electricity when connected to a washing machine and dishwasher.

Advantages of solar water heaters:

• relatively simple design;
• high reliability;
• efficient operation regardless of the season;
• long service life;
• the possibility of saving gas and electricity;
• no permission is required to install equipment;
• small mass;
• ease of installation;
• complete autonomy.

As for the negative points, not a single installation for obtaining alternative energy can do without them. In our case, the disadvantages are:

• high cost of factory equipment;
• dependence of the solar collector efficiency on the time of year and geographic latitude;
• susceptibility to hail;
• additional costs for the installation of a heat storage tank;
• dependence of the energy efficiency of the instrument on cloudiness.

Considering the pros and cons of solar water heaters, one should not forget about the environmental side of the issue - such installations are safe for humans and do not harm our planet.

The factory solar collector resembles a construction set, with which you can quickly assemble the installation of the required performance

Types of solar water heaters: the choice of design for self-production

Depending on the temperature that solar heaters develop, there are:

• low-temperature devices - designed for heating liquids up to 50 ° C;
• medium temperature solar collectors - increase the outlet water temperature up to 80 °C;
• high-temperature installations - heat the coolant to the boiling point.

At home, you can build a solar water heater of the first or second type. To manufacture a high-temperature collector, industrial equipment, new technologies and expensive materials will be needed.

By design, all liquid solar collectors are divided into three types:

• flat water heaters;
• vacuum thermosyphon devices;
• solar concentrators.

A flat solar collector is a low heat-insulated box. A light-absorbing plate and a tubular circuit are installed inside. The absorbing panel (absorber) has an increased thermal conductivity. Due to this, it is possible to achieve maximum energy transfer to the coolant circulating around the water heater circuit. The simplicity and efficiency of flat installations is reflected in numerous designs developed by craftsmen.

Inside a flat solar collector - a light-absorbing plate and a tubular circuit

The principle of operation of vacuum solar water heaters is based on the thermos effect. The design is based on dozens of double glass flasks. The outer tube is made of impact-resistant, tempered glass that resists hail and wind. The inner tube has a special coating to increase light absorption. Air is evacuated from the space between the elements of the flask, which makes it possible to avoid heat losses. In the center of the structure there is a copper thermal circuit filled with low-boiling coolant (freon) - it is the heater of the vacuum solar collector. In the process, the process fluid evaporates and transfers heat energy to the main circuit working fluid. In this capacity, antifreeze is most often used. This design allows the system to operate at temperatures down to -50 °C. It is difficult to build such an installation at home, so there are a few self-made vacuum-type structures.

The design of the vacuum solar collector is based on a set of double glass flasks

The solar concentrator is based on a spherical mirror capable of focusing solar radiation to a point. The liquid is heated in a spiral metal circuit, which is placed at the focus of the installation. The advantage of solar concentrators is the ability to develop high temperatures, but the need for a tracking system for the Sun reduces their popularity among DIYers.

Building a productive solar concentrator at home is not an easy task

For home fabrication, flat plate solar heaters built using thermal insulation materials, high transmittance glass and copper absorbers are best suited.

The device and principle of operation of a flat solar collector

A homemade solar water heater consists of a flat wooden frame (box) with a blank back wall. At the bottom is the main element of the device - the absorber. Most often it is made of a metal sheet attached to a tubular collector. The efficiency of energy transfer depends on the contact of the absorber plate with the heat exchanger pipes, so these parts are welded or soldered with a continuous seam.

The fluid circuit itself is an array of vertically mounted tubes. In the upper and lower parts, they are connected to horizontal pipes of increased diameter, which are intended for the supply and withdrawal of the coolant. The inlet and outlet for the liquid are located diagonally - due to this, complete heat removal from the heat exchanger elements is ensured. Antifreeze for heating systems or other antifreeze solutions are used as a heat carrier.

The absorber is covered with light-absorbing paint, glass is placed on top, and the box is protected with a layer of thermal insulation. To simplify the task, the glazing area is divided into parts, and in order to increase productivity, double-glazed windows are used. The closed design creates the effect of a thermos in the solar collector and at the same time prevents heat loss due to wind, rain and other external factors.

The solar water heater works like this:

1. The non-freezing liquid heated in the solar collector rises through the tubes and enters the heat storage tank through the coolant withdrawal branch.
2. Moving through the heat exchanger installed inside the storage tank, the antifreeze gives off heat to the water.
3. The cooled working fluid enters the lower part of the solar water heater circuit.
4. The water heated in the tank rises and is taken for the needs of hot water supply. The replenishment of the liquid in the heat storage tank occurs due to the water pipe connected to the bottom. If the solar collector works as a heating system heater, then a circulation pump is used to circulate water in a closed secondary circuit.

The constant movement of the coolant and the presence of a heat accumulator allows you to accumulate energy while the sun is shining, and gradually spend it even when the luminary is hiding behind the horizon.

The scheme for connecting a solar collector to a storage tank is not so complicated.

Options for homemade solar installations

A feature of do-it-yourself solar water heaters is that almost all devices have the same design of a heat-insulated box. Often the frame is assembled from lumber and covered with mineral wool and a heat-reflecting film. As for the absorber, metal and plastic pipes are used for its production, as well as ready-made components from unnecessary household equipment.

From a garden hose

A snail-shaped garden hose or PVC plumbing pipe has a large surface area, which makes it possible to use such a circuit as a water heater for the needs of an outdoor shower, kitchen or pool heating. Of course, for these purposes it is better to take black materials and be sure to use a storage tank, otherwise the absorber will overheat during the peak of the summer heat.

A flat-plate garden hose collector is the easiest way to heat your pool water

From the condenser of an old refrigerator

The external heat exchanger of a used refrigerator or freezer is a ready-made solar collector absorber. All that remains to be done is to retrofit it with a heat-absorbing sheet and install it in the case. Of course, the performance of such a system will be small, but in the warm season, a water heater made from refrigeration equipment parts will cover the hot water needs of a small country house or cottage.

The heat exchanger of an old refrigerator is an almost ready-made absorber for a small solar heater

From a flat radiator heating system

The manufacture of a solar collector from a steel radiator does not even require the installation of an absorbing plate. It is enough to cover the device with black heat-resistant paint and mount it in a sealed casing. The performance of one installation is more than enough for a hot water supply system. If you make several water heaters, you can save on heating the house in cold sunny weather. By the way, a solar plant assembled from radiators will heat utility rooms, a garage or a greenhouse.

The steel radiator of the heating system will serve as the basis for the construction of an environmentally friendly water heater

From polypropylene or polyethylene pipes

Pipes made of metal-plastic, polyethylene and polypropylene, as well as fittings and devices for their installation, allow you to build solar circuits of any size and configuration. Such installations have good performance and are used for space heating and hot water for household needs (kitchen, bathroom, etc.).

The advantage of a solar collector made of plastic pipes is low cost and ease of installation

From copper pipes

Absorbers constructed from copper plates and tubes have the highest heat transfer, therefore they are successfully used for heating the coolant of heating systems and in hot water supply. The disadvantages of copper collectors include high labor costs and the cost of materials.

The use of copper pipes and plates for the manufacture of the absorber guarantees high solar plant performance.

Solar collector calculation method

The performance of a solar solar collector is calculated based on the fact that 1 sq.m of installation on a clear day accounts for from 800 to 1 thousand W of thermal energy. The losses of this heat on the reverse side and walls of the structure are calculated according to the thermal insulation coefficient of the insulation used. If expanded polystyrene is used, then for it the heat loss coefficient is 0.05 W / m × ° C. With a material thickness of 10 cm and a temperature difference between inside and outside the structure of 50 °C, the heat loss is 0.05/0.1 × 50 = 25 W. Taking into account the side walls and pipes, this value is doubled. Thus, the total amount of outgoing energy will be 50 W per 1 sq.m of solar heater surface.

To heat 1 liter of water by one degree, 1.16 W of thermal energy is required, therefore, for our model of a solar collector with an area of ​​1 sq.m and a temperature difference of 50 °C, it will be possible to obtain a conditional performance coefficient of 800/1.16 = 689.65/kg × ° C. This value shows that a 1 sq.m installation will heat up 20 liters of water by 35 °C within an hour.

The calculation of the required performance of a solar water heater is carried out according to the formula W = Q × V × δT, where Q is the heat capacity of water (1.16 W/kg × °C); V - volume, l; δT is the temperature difference at the inlet and outlet of the installation.

Statistics say that one adult needs 50 liters of hot water per day. On average, for hot water supply, it is enough to raise the water temperature by 40 °C, which, when calculated using this formula, requires energy costs W = 1.16 × 50 × 40 = 2.3 kW. To find out the area of ​​the solar collector, this value must be divided by the amount of solar energy per 1 sq.m of surface at a given geographical latitude.

Calculation of required solar system parameters

Making solar water heater with copper absorber

The solar collector proposed for production on a sunny winter day heats water to a temperature above 90 ° C, and in cloudy weather - up to 40 ° C. This is enough to provide the house with hot water. If you want to heat your home with solar energy, you will need several such installations.

Required materials and tools

To make a water heater you will need:

• sheet copper with a thickness of at least 0.2 mm and dimensions of 0.98 × 2 m;
• copper tube Ø10 mm, length 20 m;
• copper tube Ø22 mm, length 2.5 m;
• thread 3/4˝ - 2 pcs;
• plug 3/4˝ - 2 pcs;
• soft solder SANHA or POS-40 - 0.5 kg;
• flux;
• chemicals for absorber blackening;
• OSB board 10 mm thick;
• furniture corners - 32 pieces;
• basalt wool 50 mm thick;
• sheet heat-reflecting insulation 20 mm thick;
• rail 20x30 - 10m;
• door or window seal - 6 m;
• window glass 4 mm thick or double-glazed window 0.98x2.01 m;
• self-tapping screws;
• dye.

In addition, prepare the following tools:

• electric drill;
• a set of drills for metal;
• "crown" or cutter for woodworking Ø20 mm;
• pipe cutter;
• gas-burner;
• respirator;
• paint brush;
• a set of screwdrivers or a screwdriver;
• electric jigsaw.

To pressurize the circuit, you will also need a compressor and a pressure gauge designed for pressure up to 10 atmospheres.

For soft soldering, a simple gas torch is suitable

Instructions for the progress of work

1. Using a pipe cutter, the copper tube is cut into pieces. You will get 2 parts Ø22 mm 1.25 m long and 10 elements Ø10 mm 2 m long.
2. In thick pipes, a margin of 150 mm is made from the edge and 10 holes Ø10 mm are made every 100 mm.
3. Thin tubes are inserted into the holes obtained so that they protrude inward by no more than 1–2 mm. Otherwise, excessive hydraulic resistance will appear in the radiator.
4. Using a gas burner, hot air gun and solder, all parts of the radiator are interconnected.

   

   The solar collector circuit works under pressure, so special attention is paid to the tightness of the connections

   To assemble the radiator, you can use special fittings, but in this case, the cost of the solar system will increase significantly. In addition, collapsible connections do not guarantee the tightness of the structure under variable thermodynamic loads.

5. Plugs and threads are soldered in pairs along the radiator diagonals to 3/4˝ pipes.
6. Having closed the outlet thread with a plug, a fitting is screwed onto the inlet of the assembled manifold and the compressor is connected.

   

   The compressor is connected with a fitting

7. The radiator is placed in a container with water and a pressure of 7–8 atm is pumped up by the compressor. The bubbles rising at the joints are used to judge the tightness of the soldered joints.
   

   If a suitable container for checking the collector could not be found, then you can assemble it yourself. For this, a box or a simple barrier is made from improvised means (trimming of lumber, brick, etc.) and covered with plastic wrap.

8. After checking the tightness, the radiator is dried and degreased. Then proceed to the soldering of the copper sheet. Solder the absorber sheet to the tubes with a continuous seam along the entire length of each element of the copper circuit.

   

   Soldering of the absorber sheet is carried out with a continuous seam

9. Since the solar collector absorber is made of copper, chemical blackening can be used instead of painting. This will allow you to get a real selective coating on the surface, similar to what is obtained in the factory. To do this, a heated chemical solution is poured into the container for leak testing and the absorber is placed face down. During the reaction, the temperature of the reagents is maintained by any available method (for example, by constantly pumping the solution through a vessel with a boiler).

   

   Blackening of copper is one of the most critical stages in the manufacture of an absorber.

   As a liquid for chemical blackening, you can use a solution of sodium hydroxide (60 g) and potassium persulfate or ammonium persulfate (16 g) in water (1 l). Remember that these substances are dangerous to humans, and the process of copper oxidation itself is associated with the release of harmful gases. Therefore, it is imperative to use protective equipment - a respirator, goggles and rubber gloves, and the work itself is best done outdoors or in a well-ventilated area.

10. Parts are cut out from the OSB sheet for assembling the solar collector housing - the bottom 1x2 m, the sides 0.16x2 m, the top 0.18x1 m and the bottom 0.17x1 m panels, as well as 2 supporting partitions 0.13x0.98 m.
11. A 20x30 mm rail is cut into pieces: 1.94 m - 4 pcs. and 0.98 m - 2 pcs.
12. Holes Ø20 mm are made in the side walls for the inlet and outlet pipes, and 3-4 holes Ø8 mm are drilled in the lower part of the collector for microventilation.

    

    Holes needed for micro-ventilation

13. Cutouts are made in the partitions for the absorber tubes.
14. A support frame is assembled from slats 20x30 mm.
15. Using furniture corners and self-tapping screws, the frame is sheathed with OSB panels. In this case, the side walls should rest on the bottom - this will prevent the deflection of the body. The bottom panel is lowered 10 mm from the rest to cover it with glass. This will prevent precipitation from getting inside the frame.
16. Install interior partitions.

    

    When assembling the case, be sure to use a building square, otherwise the design may turn out to be lopsided

17. The bottom and sides of the body are insulated with mineral wool and covered with rolled heat-reflecting material.

    

    It is better to use mineral wool with moisture-repellent impregnation.

18. The absorber is placed on the prepared space. To do this, one of the side panels is dismantled, which is then put in place.

    

    Scheme of the internal "pie" of the solar collector

19. At a distance of 1 cm from the upper edge of the box, the inner perimeter of the structure is sheathed with a wooden lath 20x30 mm so that its wide side touches the walls.
20. A sealing gum is glued around the perimeter.

    

    For tightness, use a conventional window seal.

21. Glass or a double-glazed window is laid, the contour of which is also pasted over with a window seal.
22. The structure is pressed with an aluminum corner, in which holes for self-tapping screws are pre-drilled. At this stage, the collector assembly is considered complete.

    

    When assembled, the thickness of the solar collector is about 17 cm

To prevent moisture ingress and heat leakage, at all stages the joints and mating points of the parts are treated with silicone sealant. To protect the structure from precipitation, the wood is coated with a special compound and painted with enamel.

Features of installation and operation of liquid heating collectors

To place the solar collector, choose a spacious place that is not shaded all daylight hours. The mounting bracket or subframe is made of wooden slats or metal in such a way that the inclination of the water heater is adjustable from 45 to 60 degrees from the vertical axis.

Connection diagram for a solar heater in a forced circulation system

The storage tank to reduce heat losses is placed as close as possible to the installation. Depending on the conditions, natural or forced circulation of the coolant is organized. In the latter case, a controller is used with a temperature sensor embedded in the outlet pipe. The pumping of the working fluid along the circuit will turn on when its temperature reaches the programmed value.

A seasonally operating system is filled with water, while year-round use of a solar water heater requires the use of an antifreeze fluid. The ideal option is a special antifreeze for solar systems, but liquids intended for car radiators or domestic heating systems are also used to save money.

Video: do-it-yourself solar water heater

Building a solar collector is not only an interesting and exciting activity. A solar water heater will save your family budget and will prove that you can protect the environment not only in words, but also in real deeds.

Thanks to my versatile hobbies, I write on various topics, but my favorite ones are engineering, technology and construction. Perhaps because I know a lot of nuances in these areas, not only theoretically, as a result of studying at a technical university and graduate school, but also from the practical side, since I try to do everything with my own hands.

Good owners of private houses are always looking for ways to save money on water heating and heating. This has become especially relevant in recent times, when utility prices have a strong upward trend almost every quarter. Nature itself comes to the rescue with its inexhaustible source of energy - solar radiation. By putting the laws of physics into practice, craftsmen find interesting ways to save money by designing and assembling solar collectors, which, probably, any homeowner can do on their own - you just have to put a little effort and skill.

A do-it-yourself solar collector can be made in multiple ways and from a variety of materials, sometimes even from those that simply “roll underfoot.” They are constructed from ordinary old beer cans, plastic bottles, hoses or pipes, using glass, polycarbonate panels and other materials.

Some of the ways to make collectors will be discussed below, but first you should study the connection diagrams - they, as a rule, are approximately common to any solar water heating systems.

Solar Water Collector Wiring Diagrams

The effective operation of the solar water heating system depends not only on what the collector is made of, but also how correctly it will be installed and connected. There are a lot of options for connection schemes, but you should not look for the most complex ones, since it is quite possible to use the basic ones that are accessible and understandable.

"Summer" version of hot water supply from a solar collector

This simple solar collector connection scheme is applicable for both domestic and domestic water heating. If hot water is needed outside in a summer building, then the tank for it is also installed in the air. In the case when hot water is distributed around the house, and the storage tank is installed there.

"Summer" collector connection option

This scheme usually provides for the natural circulation of water, and in this case, the collector battery is installed 800 ÷ 1000 mm lower than the tank level, where hot water will flow - this should be ensured by the difference in density of the cold and heated liquid. To connect the manifold to the tank, pipes with a diameter of at least ¾ inch are used. To keep the water in the storage tank in a hot state, which it will reach from heating by the daytime sun, the walls must be well insulated, for example, with mineral wool 100 mm thick and polyethylene (if a roof is not built over the boiler). But still, it is better to provide a stationary shelter for the container, since if the insulation gets wet from the rain, it will significantly reduce its thermal insulation properties.

Natural circulation is not very good for use in a system with a solar collector, as it creates a slight inertia in the movement of water in the circuit. And if the battery and the tank are far enough apart, then the water, having passed this path, will gradually cool down. Therefore, to increase efficiency, circulation is often installed. This option is suitable for heating water only in the warm half of the year, and for the winter the water from the system will have to be drained, otherwise, freezing, it will easily break T tons of ruby.

"Winter" scheme for connecting solar water heating

If you plan to use the solar collector year-round, then so that in severe colds the water does not freeze in the pipes, a special antifreeze, that is, an antifreeze liquid, is poured into the circuit instead of it. The scheme takes on a completely different look - an indirect heating boiler is installed. In this case, the antifreeze heated in the solar collector will pass through the coil-heat exchanger of the boiler, warming the water in the tank.

A "security group" is necessarily built into this system - automatic air vent, pressure gauge and safety valve, designed for the desired pressure. For the constant movement of the coolant, a circulation pump is usually used.

Solar heating option

When using solar thermal energy for home heating, an indirect heating boiler connected to the collector is also used, as well as for additional heating of the coolant - running on solid fuel or gas. On autumn or spring days, when the sun is able to heat the coolant to the desired temperature, the boiler can simply be turned off.

Solar collector - a good help for home heating

If the winters in the region are very cold, then one should not expect great efficiency from the collector, since during this period there are few sunny days, and the star itself is low to the horizon. Therefore, additional heating of the coolant and hot water is simply necessary. The only way a solar panel will help save on fuel is that not cold, but already somewhat heated water will flow into the boiler, which means that to bring it to the desired temperature, it will take less gas or wood to burn.

You also need to know that the larger the area to make a solar thermal collector, the more energy it will be able to absorb. Therefore, in order for such a system to be able to generate enough heat to heat the house, the size of the collector area must be increased to 40 ÷ 45% of the total area of ​​​​the house.

Option for hot water supply and heating from a solar collector

To use the solar collector for both heating and hot water supply, it is necessary to combine both previous options in the system, and use a special boiler for water with an additional tank having a coil through which the coolant heated by the solar battery circulates. Due to the fact that the inner tank is much smaller than the main one, the water in it heats up from the coil much faster and gives off heat to the general tank.

The collector can be included in the general system "heating - hot water supply"

In addition, the boiler must be connected to an additional heating source - it can be either an electric boiler or a solid fuel heat generator.

The temperature instability created by the solar battery can contribute to overheating of the coolant or, conversely, to its too rapid cooling in the heating and water supply circuits. To prevent this from happening, the entire system must be controlled by automation. Installed in the wiring controller temperature, which can either redirect coolant flows, or turn on or off circulation pumps, or perform other control operations.

In the diagram above, such a temperature controller is designated as a regulator.

So, with connection diagrams (strapping), in general terms, there is clarity. And now it makes sense to consider several options for self-manufacturing solar collectors.

Prices for solar collectors

Solar collectors

Solar collector from hose or flexible pipe

Those who have a private house with a garden or a cottage, of course, know that the water left in the temporary light mains after watering the beds heats up quickly. This is the positive quality of hoses or flexible pipes and was used by craftsmen, creating solar heat exchangers from them. It should be noted that such a collector will cost many times cheaper than bought in a store, but in order for the manufacturing process to be successful, some effort must be made.

On the roof - a whole battery of solar collectors

Such a collector may consist of one or more sections, in which hoses tightly coiled in a spiral “snail” are laid and fixed.

"Snail" - heat exchanger

This design can be called the simplest both in design and installation. Its main disadvantage can be called the fact that it is practically impossible to use it without the use of forced circulation, since if the pipe contours are too long, the hydraulic resistance will exceed the pressure force created by the temperature difference. However, solving the issue of installing a circulation pump is not difficult at all. And such a system, installed in a country house, will be an excellent help and will quickly pay off, including the costs (very insignificant) for the power supply of the pump.

Similar collectors are also used for heating water in pools. They are connected to a filtration system, which is necessarily equipped with a pump. Water, circulating through the pipes of the collector, has time to heat up before entering the pool.

In some cases, creating the entire system, you can do without installing a storage tank. This is possible when hot water is used only during the daytime and in small quantities. For example, in a circuit of 150 m of a pipe with an internal diameter of 16 mm, 30 liters of water can be accommodated. And if five or six such “snails” from pipes are collected into a single battery, then during the day each family member can take a shower several times, and there will still be a lot of hot water for household needs.

If someone still has doubts about the effectiveness of such water heating, we recommend watching a video that shows a test of a hose collector:

Video: the efficiency of a simple solar collector

Materials for manufacturing

To make such a solar water collector, you need to prepare some materials. It is not at all excluded that some of them can be found in a barn or garage.

• A rubber hose or a flexible black plastic pipe with a diameter of 20 ÷ 25 mm is, in fact, the main element of the system in which heat exchange will occur when water circulates. The number of hose will depend on the size of the solar battery - it can be 100 or 1000 meters. The black color of the hose is preferred because it absorbs heat more than all other shades.

It should be noted right away that metal-plastic pipes are not particularly suitable for the manufacture of a collector, even if they are covered with black paint. The fact is that their plasticity in this case is insufficient - they break at bends of a small radius and thus, even if the integrity of the walls is not violated, the intensity of the water flow will decrease.

Hoses are sold in coils of 50, 100 or 200 meters. If you plan to make a large volume battery, then you will have to purchase several bays. In the event that it is planned to use, for example, 50 or 100 m of hose in each section, then you should not buy a whole 200-meter bay, it is better to purchase a ready-made measured hose. This will save time during installation.

The hose can be laid not only in a round spiral, but also oval, as well as in the form of a coil.

As a good alternative, you can also try modern PEX pipes. They have good plasticity, but how to give them black, if it is not on sale, is easy to figure out.

• If the slope of the roof on which the collector battery will be installed is steep, then special boxes are made for hose spirals - from bars, plywood or metal sheet. This will require bars 40 × 40 or 40 × 50 mm, plywood 6 mm thick, or a metal sheet 1.5–2 mm.

The blanks of the future module are processed (wood) or anti-corrosion compounds (metal). Then a box is assembled from them into one or more spirals.

By the way, as the sides of the box, you can use old window frames, on which the bottom part is simply mounted.

• For pre-treatment of metal and wood, it is necessary to purchase antiseptic, anti-corrosion and priming compounds.
• Hoses (pipes) will experience considerable loads both from the mass of the coolant and from temperature extremes and internal pressure. Therefore, they will try to break the laying, deform, sag, so you need to provide special fasteners to maintain them in the initially set position.

It can be a metal strip, which is fixed between the pipes with self-tapping screws.

Another option is to loosely tie with a tight cord or plastic tie-tie with a cross or cross bar. But still, this fastening method is more suitable for a plastic pipe than for a hose, since it can sag on the cord when the rubber expands. If a reinforced rubber hose is chosen for the collector, then this method is quite suitable for fixing.

Another fastening option suitable for a plastic pipe or reinforced hose can be wide-head nails. They can be hammered either into the bottom of the box (in this case it must have a thickness of at least 10 mm), or onto a kind of cross made of a bar.

• It will be necessary to prepare the connecting elements for the hose or pipes. There are a lot of varieties of such fittings, but you need to choose exactly those that are intended for selected for manufacturing material collector.

In addition to such connectors, threaded fittings will be required to switch from a plastic or rubber pipe to a common metal one. Such a connection will be necessary if the collector will consist of several modules.

To know how many connecting elements are required, you need to draw in advance a schematic diagram of the system being created and calculate their number on it.

• To combine all the modules into a single battery, two collector - cut metal pipe. Through one of them, fixed at the bottom of the battery, cold water will flow into the heat exchangers, and in the second, fixed at the top, warm water will be collected.

The upper pipe will be connected to the storage tank, that is, it will go to the consumer. It should have a diameter of 40 ÷ 50 mm.

Battery mounting

Having prepared everything you need, you can get to work.

• First you need to treat all the wooden parts of the future structure with an antiseptic.
• Further, if the bottom of the modules is made of a metal sheet, it must be coated with an anti-corrosion compound. Usually, mastic is used for this purpose, designed to cover the bottoms of cars.

Known to all motorists "anticorrosive" - ​​what you need

• After the compositions have dried on the prepared elements, single or common modules are assembled from them.
• Then hoses are laid in them, for which holders are fixed.

• For free passage of pipes through the sides of the modules, holes are drilled for them - in its upper part and lower. Accordingly, a cold water inlet pipe is led into the lower hole, and a heated outlet is led into the upper hole.
• If several modules are mounted vertically, or one common one, into which several "snails" of the pipe are also placed, one above the other, then the lower end of each of the spirals is connected to the upper output of the underlying one - and the entire "column" is switched according to this sequential principle. The lowest end is connected to a common metal manifold through which cold water will flow. All adjacent vertical rows are mounted in the same way - with a common connection to the supply manifold.

• Accordingly, the upper ends of the hoses of the uppermost horizontal row of modules are connected to a metal collector pipe, through which hot water is drained for consumption.
• The spiral collector circuit can also be mounted on a metal sheet installed not on the roof, but near the house, on its south side, or near the pool, if it requires heating. In this case, the metal base will contribute to faster heating of water and heat retention in pipes, as it has good thermal conductivity and heat capacity.

• Another option for a thermal solar collector can be laying the circuit on the roof plane in special boxes in long parallel rows along the entire length of the roof.

Prices for XLPE pipes

XLPE pipes

Video: simple linear tube solar collector

Enhance the effect with plastic bottles

The figure shows a solar collector made of hoses (pipes), the efficiency of which is greatly increased by using ordinary plastic bottles. What is the "feature" here? And there are several of them:

The action of a plastic bottle as a casing - schematically

• Bottles play the role of a transparent casing, and do not allow air currents to take away heat during absolutely unnecessary mutual heat exchange. Moreover, the air chambers themselves become a kind of heat accumulators. There is a greenhouse effect, which is actively used in agricultural technology.
• The rounded surface of the bottle plays the role of a lens that enhances the effect of sunlight.
• If the bottom surface of the bottle is covered with a reflective foil material, then the effect of focusing the rays in the zone of the pipe passage can be achieved. Heating will only benefit from this.
• Another important factor. A plastic transparent surface will to some extent reduce the damaging negative effects of ultraviolet rays, which neither rubber nor plastic "like". Such a circuit should last longer.

To make such a solar collector you will need:

1 - Rubber hose, black metal or plastic pipes - as a heat exchanger.

2 - Plastic bottles that will become a casing around the pipes of the circuit.

3 - In the bottles, in their half, which will be adjacent to the base, foil or other reflective material may be inserted. The reflective part should look towards the sun.

4 - It will be quite easy to mount the stand from a bar or a metal pipe.

5 - Storage tank for heated water, which must be connected to the intake point - faucet, shower, etc.

6 - Cold water tank that can be connected to the water supply system.

Installation of a solar collector

The assembly of the version shown in the upper diagram is as follows:

• To begin with, a stand is mounted from a metal pipe or bar. If it is made of wood, then it must be coated with an antiseptic composition, but if it is made of metal, then it must be treated with an anti-corrosion agent. It is necessary to calculate the length so that an even number of bottles is installed between the two racks.
• On racks, at a distance the width of the bottles, horizontal strips are fixed, on which it will be possible to make additional fastening for the coil. In addition, they will betray the frame additional rigidity.
• Next, the required number of plastic bottles is prepared - the bottom part is cut off from them so that one bottle with the side of the neck fits snugly into the resulting hole.

• A hose (pipe) of the required length is taken, which will be enough for laying coil circuit on a ready-made frame-stand.

Stepping back from the edge of the hose 100 ÷ 150 mm, make a mark of the place of its fastening. Then, through this edge, the required number of prepared bottles is put on the pipe, which will be enough to completely close the area to the opposite rack. The bottles are installed tightly one to the other, so that the neck of the second one enters the hole cut in the bottom of the previous one.

• When the pipe section for laying the upper section of the coil is completely covered with a bottle box, its edge is fixed on top of the left rack of the frame. For fastening, you can use clip-holders for plastic pipes with a latch, the desired size.

• If necessary, the position of the bottles is adjusted so that their foil half is at the bottom, near the collector frame.
• Then the pipe is given a smooth turn, and it snaps back onto the clip.
• The next step is to put bottles on the pipe again, and it is already fixed on the left rack. This follower is continued until the entire frame is filled with a collector coil.
• Now it remains only to “pack” the fittings through which the resulting collector will be connected to the cold water supply and to the hot storage tank.

Here's what can happen in the end - you can't imagine it easier!

Such a collector, as you can see, absolutely not difficult in manufacturing, but it can become a good "helper" in a private house, taking on the functions of heating water.

By the way, solar energy can be used not only for heating water, but also for supplying heated air to rooms. For example, how to make it yourself, you can find out if you follow the link to a special publication of our portal.

Video - do-it-yourself solar power plant assembly

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Making your own solar water heater

Every day our earth is illuminated by the sun, and this is a huge amount of energy. If you use at least part of it, then you will have hot water for free, for this you just need to make a solar water heater with your own hands.

Solar collector diagram: 1 - tubes with liquid (water, antifreeze), 2 - heat-insulating housing, 3 - reflector, 4 - stiffening frame, 5-6 - tanks for cold and hot water.

Using the heating tank

The simplest water heating system that people have been using for many years is a tank that is heated by sunlight. Despite the fact that this is an elementary design, it is quite effective and is often used in private homes for a "summer shower".

If this design is equipped with a tank where warm water will be stored, then its efficiency will increase significantly.

In order to make a solar water heater with your own hands, you need to know that the heating tank will be the most important part in it. You can use a metal barrel, but a special polyethylene tank with a capacity of about 200 liters is better. It is more convenient, as it does not corrode and does not require painting, unlike a metal structure, it is light in weight and easier to mount on the roof.

During the day, under the influence of sunlight, the water in such a tank heats up to 40-45 ºС and this is enough for domestic needs. But if you don’t use all the water during the day, then it cools down overnight, and you won’t be able to use it around the clock. In order to minimize heat loss, you can either insulate the tank itself, or collect warm water in an insulated container.

Many people living in private homes use electric and gas boilers to heat water. It is they who can be used to store water heated during the day. This solar water heater has a simple structure. And it consists of a tank, a boiler and a tap. From the water supply, water is supplied to the tank, after which the flow of water is blocked. That warm water that has not been used during the day is drained into the boiler in the evening and can be used further. If the heating tank is not used, then the water from the water supply directly enters the boiler, the whole process is regulated by taps.

Such a solar water heater has a simple design, but it has two serious drawbacks:

• every day you have to collect and drain water from the heating tank;
• warm water can only be used on days when the weather is sunny and the air temperature is at least 20 ºС.

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Passive solar water heater

In order to be able to receive warm water even in cloudy weather, the heating tank must be replaced with a solar collector.

In order to design such a solar heater, you first need to make a collector. In order for it to work reliably, be easy to assemble and have a low price, it is necessary to choose the right material for the manufacture of the collector. Thin-walled copper or metal pipes are considered the most reliable material, but they are difficult to install and they are heavy.

A simpler and more convenient option is to manufacture a collector from metal-plastic or polypropylene pipes, but in this case there is a high probability of leakage due to damage. If you use an ordinary garden hose, then all these shortcomings disappear, and all that remains is to twist it in the form of a spiral. Its flexibility allows you to make the structure a single whole, there are no connections, and water is connected directly from the collector to the house.

The simplest garden hose solar water heater consists of the hose itself, window glass, foam insulation, and a base. The water is heated by the sun's rays, which fall through the glass onto the water hose. After the hose is heated, the heat from it is reflected by the glass and is used again to heat the water. In summer, the optimal angle of inclination of the collector is 35º, and in the autumn-spring period 40º.

Before starting work, air is expelled from the solar collector, after which it is connected to the boiler. Under the action of the thermosiphon effect, water from the boiler flows into the collector. To turn it off, you just need to turn off the tap.

The disadvantage of this design is that periodically it is necessary to regulate the water supply to the solar collector.

To calculate such a water heater, it must be taken into account that m hose with a diameter of 25 mm at an air temperature of 25 and clear weather heats up to a temperature of 45 ºС 3.5 liters of water per hour. If the length of the hose is 10 meters, then 35 liters of water will be heated per hour. In summer, the sun shines for 8 hours, so we get 280 liters of hot water.

You can use such a heater until the air temperature is below 8 ºС. At negative temperatures, the water from the collector must be drained.

Energy resources. Free solar energy will be able to provide warm water for household needs at least 6-7 months a year. And in the remaining months - also help the heating system.

But most importantly, a simple solar collector (unlike, for example, from) can be made independently. To do this, you will need materials and tools that can be bought at most hardware stores. In some cases, even what is found in an ordinary garage will be enough.

The solar heater assembly technology presented below was used in the project "Turn on the sun - live comfortably". It was developed specifically for the project by a German company Solar Partner Sued, which is professionally engaged in the sale, installation and service of solar collectors and photovoltaic systems.

The main idea is that everything should turn out cheap and cheerful. For the manufacture of the collector, fairly simple and common materials are used, but its efficiency is quite acceptable. It is lower than that of factory models, but the difference in price fully compensates for this shortcoming.

The sun's rays pass through the glass and heat the collector, and the glazing prevents heat from escaping. The glass also impedes the movement of air in the absorber; without it, the collector would quickly lose heat due to wind, rain, snow or low outside temperatures.

The frame should be treated with an antiseptic and paint for outdoor use.

Through holes are made in the housing for supplying cold and removing heated liquid from the collector.

The absorber itself is painted with a heat-resistant coating. Conventional black paints at high temperatures begin to peel off or evaporate, which leads to darkening of the glass. The paint must be completely dry before you set the glass cover (to prevent condensation).

A heater is laid under the absorber. The most commonly used mineral wool. The main thing is that it can withstand fairly high temperatures during the summer (sometimes over 200 degrees).

From below, the frame is covered with OSB boards, plywood, boards, etc. The main requirement for this stage is to make sure that the bottom of the collector is reliably protected from moisture getting inside.

To fix the glass in the frame, grooves are made, or strips are attached to the inside of the frame. When calculating the dimensions of the frame, it should be taken into account that when the weather (temperature, humidity) changes during the year, its configuration will change slightly. Therefore, a few millimeters of margin are left on each side of the frame.

A rubber window seal (D- or E-shaped) is attached to the groove or bar. Glass is placed on it, on which a sealant is applied in the same way. From above, all this is fixed with galvanized tin. Thus, the glass is securely fixed in the frame, the seal protects the absorber from cold and moisture, and the glass will not be damaged when the wooden frame "breathes".

The joints between the sheets of glass are insulated with sealant or silicone.

To organize solar heating at home, you need a storage tank. The water heated by the collector is stored here, so you should take care of its thermal insulation.

As a tank you can use:

• non-working electric boilers
• various gas cylinders
• barrels for food use

The main thing to remember is that pressure will be created in a sealed tank depending on the pressure of the plumbing system to which it will be connected. Not every container is able to withstand a pressure of several atmospheres.

Holes are made in the tank for the inlet and outlet of the heat exchanger, the inlet of cold water, and the intake of heated water.

The tank houses a spiral heat exchanger. For it, copper, stainless steel or plastic are used. The water heated through the heat exchanger will rise up, so it should be placed at the bottom of the tank.

The collector is connected to the tank using pipes (for example, metal-plastic or plastic) drawn from the collector to the tank through the heat exchanger and back to the collector. Here it is very important to prevent heat leakage: the path from the tank to the consumer must be as short as possible, and the pipes must be very well insulated.

The expansion tank is a very important element of the system. It is an open reservoir located at the highest point of the fluid circulation circuit. For the expansion tank, you can use both metal and plastic containers. With its help, the pressure in the manifold is controlled (due to the fact that the liquid expands from heating, pipes can crack). To reduce heat loss, the tank must also be insulated. If air is present in the system, it can also exit through the tank. Through the expansion tank, the collector is also filled with liquid.