Make a solar collector with your own hands. Solar water heater: the possibility of using a geo-collector and self-manufacturing of the device
Alternative heat sources, although they are quite efficient and economical in operation, cannot fully occupy a niche. The reason is the high cost, which differs from traditional heating sources at times. So, for example, a solar collector of a standard type with an absorption area of 1.66 sq. m. will cost an average of $ 3,000, taking into account installation costs and the cost of the equipment itself, while the simplest boiler - 15,000 rubles, including installation and piping. There is only one way out - to make a solar collector with your own hands, for which materials that are quite affordable can be used. How to do it right and in what sequence - in our article.
Principle of operation
The operation of this unit is based on the absorption of solar thermal energy and its transfer to the coolant with practically no losses. Energy is received by the so-called. a receiver, which is a black or dark brown metal tube. The heat carrier is water, in very rare cases - air.
The dark color is used to enhance absorption, since it is this color that allows the intense accumulation of heat.
Based on the design features, the following types of solar collectors are distinguished:
- air;
- water.
In turn, water collectors are subdivided into:
- vacuum;
- flat.
Regardless of the design, all collectors are, in fact, a simple metal panel, enclosed in a sealed box, receiving, accumulating and transmitting thermal energy.
To enhance heat transfer, the receiver is equipped with ribs, and the box itself is insulated with special materials. The front side is presented in the form of transparent glass, excluding the retention of solar energy, on the sides there is an opening with a flange, where either another panel or an air outlet can be connected.
Solar collector diagram:
Installation of solar collectors is rational only in the case of using several panels. Heat transfer from one will be minimal. A powerful fan is needed to blow warm air from the collector, since it will not move by itself.
The schematic diagram of the air system is shown in the figure below:
Scheme of work
It is very simple to make such a collector, but “homemade products”, even in the amount of several copies, will not provide the house with the necessary volume of hot water, especially in cloudy weather. In order for the house to have not only heating, but also hot water supply, we recommend installing it. Which one to choose for a summer residence - you will find out in the corresponding article.
Flat water manifold
This is the simplest type of equipment that is easy to make with your own hands, even without preliminary preparation. In this case, the body is made of metal or aluminum, where a heat sink is inserted - a plate with an embedded copper coil. The plate is coated in black to enhance absorption, and a regular glass pane is used as a cover. On the lower side, there is thermal insulation on a plate, which acts as an interlayer between the receiver and the bottom of the case.
The design of this type of collector includes the following elements:
- Receiver is a black-painted plate that absorbs heat and transfers it to the coolant.
- Glass is designed to perform 3 tasks at once:
- protection from wind, precipitation and debris;
- exclusion of weathering of heat from the box;
- passing ultraviolet rays to the receiver.
The entire structure must be completely sealed, otherwise the heat will escape through the cracks and the remaining volume will not be enough to heat the coolant.
Considering the simplicity of the design and the minimum of materials, this type is the most popular and profitable in terms of price-quality ratio.
It is advisable to use these types of heaters only in the southern and southeastern regions, where the number of sunny days exceeds 60% per year. With a decrease in temperature, the efficiency of the heater is reduced to a minimum due to high heat losses through the body.
How to make yourself
Before proceeding with the actual manufacture, it is necessary to determine the size of the future unit. The golden rule applies here - the more the better. It is clear that the size of the collector will be limited by the roof area, but it is better to use it to the maximum so that this heater becomes a truly effective alternative equipment.
For the body of the device, wood with a minimum heat transfer coefficient is best suited. Thermal insulation should be placed on the layer of the box. It can be mineral wool or polystyrene with a layer of at least 5-7 cm. As a cover, ordinary window glass is used - the thickness in this case is not important. The simplest material for the future collector will be an old window frame with preserved glass. The only thing that is required of you is to make a receiver and a coil.
How to make a manifold from a balcony door:
The list of materials for the receiver is very extensive, but the most popular are:
- thin-walled copper tube that bends easily and takes any desired shape;
- polymer pipes with a thin wall and small diameter;
- minimum diameter polyethylene pipes for water supply;
- heat exchanger from a used refrigerator;
- panel radiator;
- regular garden hose.
Any of the listed materials must be painted black. Again, this is necessary for an increased and accelerated accumulation of solar thermal energy and its transfer to the coolant.
Some craftsmen manage to use the most inappropriate materials for the receiver, from PVC bottles to beer and Coca-Cola cans. This is not the most rational solution, which will provide only 25-30% of heat transfer.
Manufacturing process
Assemble a wooden case without a top cover. On the bottom you put thermal insulation - mineral wool, polystyrene, polystyrene, etc., close it on top with a metal sheet, which should correspond in area to the dimensions of the wooden case. This is the base of the receiver and should be painted black.
Copper tubes are the most suitable option because they have a high degree of heat dissipation.
Fasten the tubes to the base with metal brackets, screw them with wire, or choose another method that is acceptable to yourself. Lead outside the box 2 fittings to which water will be supplied.
Considering that this type is called flat, it is closed hermetically with glass. There should be no gaps, no cracks, no loose flap anywhere.
The glass can be replaced with a transparent cellular polycarbonate, which is more resistant to precipitation, will not break in a rainstorm or hail, and will not burst in heavy snow.
After the entire structure is assembled, install it on the roof at an angle of 30-450 and connect it to a container with water by means of fittings. If we are talking about a small volume of the tank, it is possible to create a natural circulation of water, but it is better to install a circulation pump, which ensures the forced movement of water in a closed system.
Solar collector operation with circulation pump:
Solar collectors are one of the few types of heating equipment, the operation of which does not cost the owners even a few cents. Using solar energy to heat your home and hot water is the perfect solution for those who are accustomed to using the budget rationally.
Unfortunately, this method is not suitable for everyone. In the northern, western and eastern regions, such an acquisition is impractical due to the small number of sunny days. But for residents of the southern regions, this option is ideal, the main thing is the optimal thermal insulation of the case. In this case, we can even talk about heating the house during the cold season.
DIY solar collector - overview, piping:
It is, indeed, very simple - to make a solar water heater with your own hands. But first you need to decide how the hot water will be used. The design of the water heater will also depend on this. And it can be very simple. For example, an ordinary barrel of water on the roof of a small booth in the country. And a divider is inserted into the bottom of this very barrel. This is an impromptu outdoor shower. Or a water heater can be very complex, using mirrors, vacuum tubes, pumps, solar panels.
Of course, if we are only talking about washing after working in the country garden, then here, indeed, it is quite enough to install a barrel on an elevation, paint it black, insert a splitter shower into the bottom, fill this barrel with water. This is the most primitive solar water heater, the water supply of which is enough to take a shower after agricultural work in a summer cottage.
But the dacha is, in fact, not only a garden and a vegetable garden. A summer house is, first of all, a place for relaxation. And you need to equip this place so that you can not only have a good time here, but also live. Solar panels will provide the home with electricity, and solar water heaters will heat water for both domestic needs and home heating.
Types of solar water heaters
Structurally, solar water heating systems can be divided into three types. These are systems with flat collectors, vacuum tubes and parabolic cylindrical concentrators. All of them are currently produced by the industry. The principle of operation for all systems is the same - the heat carrier is heated, which enters the heat exchanger of the expander tank and gives up its heat to the water.
The simplest is a solar water heating system based on a flat collector. In its simplest form, this system consists of one or more flat-plate collectors and an expansion tank. The collectors are located below the tank.
The water heated in the collector according to the laws of convection rises into the tank, and the cold water from the tank sinks into the collector. This is the so-called free-flow principle of hot water supply. But, as a rule, solar collectors are installed above the tank, and in this case the convection circulation of water does not work, therefore it is necessary to install a water pump in the system to supply cold water to the heating zone.
Diagram of the simplest solar water heating system
The most efficient water heating system is based on vacuum tubes. A vacuum tube is a structure of two tubes inserted into one another. The outer tube is made of glass, the inner tube is made of copper, and its upper part is somewhat wider than the main one and is sealed.
This copper tube is coated with black heat-resistant paint. Air is pumped out of the space between these tubes to ensure the best thermal insulation. The inner tube contains a low-boiling liquid.
Under the influence of solar radiation, the copper tube heats up, the liquid in it evaporates, the vapor rises upward, heating the tip of the tube. The tip can be heated up to 250 ° C. It is inserted into the pipe through which the coolant circulates. Giving heat to the coolant, the steam in the copper tube condenses, and the cooled liquid descends down the walls. The cycle repeats endlessly. The coolant enters the tank heat exchanger, heating the water in it.
Vacuum tube diagram
Unlike solar collectors, in which vacuum tubes serve as heating elements, in parabolic cylindrical concentrators, the heating zone is at the focus of a long parabolic mirror. The temperature at the focus of this mirror can reach 300 ° C. The heated coolant circulating in the system enters the heat exchanger of the expansion tank, heating the water in it.
The disadvantage of such a solar water heating system is the need to position the parabolic mirror in the sun. Industrial systems are equipped with sun tracking devices and actuators that rotate the mirror.
Diagram of a solar water heater with a parabolic cylindrical concentrator
Homemade solar water heaters
For a summer cottage with only one light summer house, where people come only during the warm season and only on weekends, it makes no sense to build a capital hot water supply system. It will take very little time and money to make a solar water heating system here.
For the construction of a solar collector, you will need boards measuring 200x15x2 cm, fiberboard, tempered glass, a sheet of tin or roofing iron measuring 2x1 meters, wooden bars 5x5 cm 1 meter long, a copper tube, polystyrene, black heat-resistant paint, "Hermetic" glue.
Sectional flat collector
First, a 2x1 meter box is knocked out of the boards. The bottom of the box is made of fiberboard. For strength, crossbars from bars are nailed in two places. All joints of the outer walls of the box are carefully processed with "Hermetic" glue. Then thermal insulation - polystyrene - is placed on the bottom of the box. A flat coil bent from a copper tube is rigidly attached to the sheet of tin.
So that there are no creases on the tube when bending, ordinary salt must first be poured into it, which is then easily washed out. As such a coil, you can use a coil from an old refrigerator. Previously, it will need to be thoroughly rinsed from freon residues.
Homemade flat collector based on a heating battery
Then this sheet of tin with a coil is mounted in a box on stiffening bars. The ends of the coil are led out into holes specially drilled in the box. Then the whole structure is covered from the inside with black heat-resistant paint. Preferably in two layers. After the paint dries, the box is covered with glass. All joints, seams, openings with the output pipes of the coil are carefully sealed. Outside, the box is covered with silver paint. The solar collector is ready.
Homemade flat solar collector for heating water in the pool
Now it's the turn of the expansion tank. From what to make a tank with a capacity of 100 - 120 liters, it does not really matter. It is important that this tank is carefully covered with a layer of thermal insulation. In the lower part of the tank there is a spiral-shaped copper coil of the heat exchanger, which is connected with pipes to the collector. The tank itself will be filled with water from the mains.
The water level in the tank must be controlled by a float valve. After the collector is permanently installed in a place with maximum sun exposure, it is connected to the heat exchanger coil in the tank. A low-power water pump is connected to the coolant circuit to ensure circulation. After the completion of all preparatory work, water with antifreeze is poured into the collector system so that the coolant does not turn into ice during possible night frosts. The hot water supply system is ready for operation.
For a summer residence with more serious communications, a more thorough water heating system will also be required. After all, hot water may be needed here, for example, for a pool, greenhouse, for heating a house in winter. In this case, it is advisable to use sets of vacuum tubes as collectors. Even in winter, in idle mode, the temperature at the tip of such a tube exceeds 200 ° C.
Connecting vacuum pipes to the coolant circuit
Otherwise, the device of the hot water supply system is no different from a system with a flat collector.
Making a helium heater with your own hands is not at all difficult. It will be much cheaper than similar industrial products, for which the cost of the simplest is 35-40 thousand rubles. The cost of complex systems can reach several hundred thousand rubles. A well-made collector with your own hands will heat water no worse than a branded one, but it will cost much less.
The sun is the largest source of safe and free energy. And if earlier people could not use it, now there are technologies that help provide a house with heat and hot water only at the expense of the sun. Using collectors is a cost-effective and affordable way to make a country house more comfortable. You just need to choose the right solar collector (or make it yourself), and then integrate it into the existing heating system.
What is a solar water heater
A collector (water heater) is a device that collects energy from the sun's rays and converts it into heat. The sun heats up the coolant in the collector, which is then used for hot water supply and heating or for generating electricity.
Devices associated with the energy of the sun, it is correct to call solar plants or solar collectors (from the name of the ancient Greek sun god Helios).
Modern solar water heaters can be complex, but any owner of a private house can independently make a device for their own needs. The main thing is to figure out what this device is for.
Three collectors fully satisfy the family's needs for hot water and heating
Scope of use of solar plants
In our country, many people still associate the phrase solar water heater with a black tank on the roof of a summer shower booth, but this technology is successfully used all over the world. Solar collectors are common in the southern regions of Europe. Residents of private homes in Italy, Spain and Greece are legally required to use solar water heaters. China is not lagging behind the West either. There, solar water heaters are installed on the roofs of high-rise buildings and provide hot water to all apartments. In 2000, there were so many solar plants in the world that, put together, they would occupy more than 71 million m 2. Almost 15 million m 2 of them would be European.
Solar vacuum collectors almost completely occupy the roofs of Chinese new buildings
Such devices are used for hot water supply of domestic premises and industrial buildings, heating of private houses, office buildings, workshops. They are most in demand in the food and textile industries, since it is in this area that there are many production processes using hot water.
In the private sector, each person from Germany has 0.14 m2 of solar collector area, from Austria - 0.45 m2, from Cyprus - 0.8 m2, and from Russia - 0.0002 m2. The intensity of solar illumination in Russia is only 0.5 kW * h / m2 less than in the south of Germany. This means that the low popularity of solar collectors in the northern regions is not due to geographical reasons.
With an extensive manifold system, even pool water can be heated
Types of solar collectors
Engineers have developed flat, tubular with vacuum, concentrators with parabolic cylindrical reflectors, aerial, solar towers and other types of installations. The most popular for domestic purposes are flat and vacuum water heaters.
Table: Comparative characteristics of flat and vacuum collectors
Flat collector | Vacuum manifold |
---|---|
Easy to do with your own hands from scrap materials. | Manufactured in an industrial setting or assembled from factory parts. |
Pays off quickly. | Pays off three times longer than flat. |
Less likely to overheat in hot weather. | Prevents accumulated heat from returning to the environment. |
Works effectively in summer or in countries with hot climates. | Suitable for cold regions, works in winter at temperatures down to -30 o C. |
It has a high windage, so a strong gust of wind can blow it off the roof. | The wind passes freely between the vacuum tubes, so the probability that the collector will not be hit by the storm is higher. |
It cleans itself of snow, frost and ice. | Productivity is 2-3 times higher than that of a flat collector (with equal areas). |
Features of Flat Panel Solar Water Heaters
The device is a panel, inside of which are located copper pipes with a dark coating. They heat up water, which is then collected in a tank and used for hot water supply (hot water supply). If you make the collector yourself, then expensive components can be replaced with available materials:
- instead of copper pipes, you can take steel, polyethylene or just a radiator from an old refrigerator;
- a wooden frame can become a replacement for a metal one, although it weighs more;
- the chrome-plated absorber will replace the usual black paint;
- a sheet of glass or cellular polycarbonate will serve well as a protective cover, and foam plastic will serve as a heater.
The main thing is to ensure the tightness of the panel, but for this it is enough to seal all the seams with construction silicone. The main disadvantage of such devices is that the heated coolant radiates heat into the air and cools a little before entering the storage tank. The use of thermal insulation and sealing of seams is designed to combat precisely this effect.
Expensive parts of an industrial collector can be replaced with cheaper counterparts, for example, steel pipes can be used instead of copper pipes, and the device frame can be made of wood
If water is not taken from the flat collector, on a hot sunny day it can heat up to 190–210 o C, which can lead to rupture of pipes with a coolant or connecting elements. For those who occasionally use a solar water heater, it is important to install a storage tank that can eliminate excess pressure in the pipes. Another option is to use mineral oil rather than water as a heat sink. Its boiling point is higher, which reduces the risk of damage to the system. In this case, a heat exchanger is needed, in which the oil will transfer the accumulated heat to the water without direct contact.
Flat solar collectors are cheaper and easier to manufacture, but are only suitable for summer use in the country or as an auxiliary water heater. Use them for domestic hot water only.
Features of vacuum collectors
This type of solar water heater consists of individual tubes, each of which is in an airless environment. This design made it possible to reduce heat loss on the way from the collector to the storage tank and increase the efficiency of the system. Thanks to this, vacuum collectors work perfectly during the changing seasons (autumn, spring) and in winter.
Copper tubes are also used in vacuum solar water heaters as this material provides good heat transfer and hygiene at the same time. The rest of the elements are similar: glass (borosilicate for better heat transmission), under it is a black absorbing layer, a tube with a heat carrier and a substrate. It is easier to ensure the tightness of the system, since there is only one seam - the connection between the tube and the storage tank.
Cold water gradually heats up from alternate contact with hot copper pipes. This is the only way to dissipate heat from a vacuum solar plant, so it is important to provide it with a regular flow of cold water, that is, use hot water throughout the day. To increase the durability of the system, antifreeze is used as a coolant in vacuum solar collectors. It tolerates heating up to 300 ° C well and does not freeze when the temperature of the device drops to -40 ° C on a cloudy day.
For year-round hot water supply and heating of a country house, a vacuum solar collector is required. It is more expensive, but more efficient and reliable than a flat one.
It is impossible to create a full-fledged vacuum solar collector with your own hands: making a thick-walled tube from borosilicate glass is unthinkable in artisanal conditions. Therefore, a more reliable option would be to buy factory flasks (coaxial and feather varieties are offered) and assemble the solar water heater on site. But since even such work requires remarkable locksmith skills, it is better to buy a finished product with a guarantee from the manufacturer.
Which system to integrate a solar water heater into
In order for hot water to start flowing out of the tap, it is important not only to choose a collector, but also to create a whole system for it from a storage tank, connecting pipes, taps and other elements.
Types of circulation
It is necessary to determine if you can install the storage tank above the manifold level. It depends on which of the two types of circulation will be in the system.
- Natural circulation is created due to the difference in density of cold and hot water... The heated liquid tends to rise, which causes such an arrangement of the storage tank. If the roof is complex, choose a well-lit place for the manifold and place the tank under the ridge.
- Forced circulation systems work thanks to a pump that pumps warm water into a prepared tank. In this case, it becomes possible to place the elements of the system far from each other, for example, to put a storage tank in the attic or in the basement. This is better for the exterior, requires less effort to insulate the tank itself. But the pipes leading from the collector to the tank are necessarily equipped with thermal insulation, otherwise there is a risk of losing all the heat along the way. Forced circulation requires the use of electricity, so if there is no electricity at the dacha or often power outages, this option will not work.
If you decide to use a heat transfer oil in the manifold, provide a pump for forced circulation. Otherwise, due to the low coefficient of expansion of the oil, the system simply will not work.
Selecting the type of circulation circuit
Three types of systems are common:
- Open loop. This is the easiest way to supply hot water to your home. Its main difference is that the coolant in the collector is necessarily water. First, it heats up in tubes, then enters the storage tank, and then directly into the faucet in the kitchen or bathroom. That is, the water does not circulate in a circle, but in an open circuit, a new portion is heated each time.
- Single-circuit. It is preferable when it is supposed to heat the house with the help of solar heat or to make the operation of electric heating cheaper. Its difference is that the water heated by the sun enters the heating pipes. The coolant moves in a circle in the system. This is a closed circulation cycle. Since the solar collector is used in winter and in the off-season, choose vacuum models and include an additional heater in the system. An electric or gas boiler helps to bring the coolant to the desired temperature on cold and cloudy days, as well as at night.
- Double-circuit. This option involves the transfer of heat from the collector to the system through a special heat exchanger. Since there is no direct contact between the coolant and water, oil or antifreeze is used in the collector. The system is optimal for country houses in which people live throughout the year. In it, the collector is used both for hot water supply and for heating at the same time. As a rule, a boiler and / or a boiler is also integrated into it for additional heating of water, and several collectors are used (depending on the number of residents and the climatic characteristics of the region).
In a double-circuit circulation system, there is no direct contact between the coolant of the solar water heater and water
An open-loop circulation system is effective for DHW summer cottages, a double-circuit one - for full supply (hot water supply and heating) of a country house.
How to make a flat solar collector with your own hands
This requires a drawing. You will also need to calculate the area of the water heater in accordance with the needs of the family. This parameter is determined by the formula: A = K * F * SF / (G * η) AW = 1 / (G * η) A = K * F * SF * AW, where:
- A - collector area, m2;
- AW is the reduced area that is capable of generating 1 kW * hour per day, m2 * day / (kW * hour);
- Η - efficiency of one collector,%;
- G - total solar radiation per day, typical for a given area, kW * hour / (m2 * day);
- K - coefficient that takes into account the magnitude of the angle of inclination of the collectors and their orientation relative to the cardinal points;
- F is the energy required to heat water per day, kW * hour / day;
- SF is the share of the sun's energy in covering the heat demand,%.
For the construction of the collector, you will need a detailed drawing indicating the number and size of parts
Tools and materials for work
For the manufacture of a flat solar collector measuring 2.28x1.9x0.1 m with metal-plastic pipes and a wooden frame, you will need:
- hacksaw or jigsaw for cutting wood and plywood;
- scissors for metal-plastic pipes;
- screwdriver;
- brushes and a spray gun or spray paint can for blackening mounted pipes.
Sequencing:
- Assemble a box for the base of the collector from two sheets of plywood measuring 1.52x1.52 m 1 cm thick.One of them cut out to create sides for details: 0.76x0.38 m in size - 4 pcs., 1.52x0.76 m in size - 1 PC.
- Paint the inner surface of the resulting box with black matte paint, and the outer surface with white or cover with a protective varnish.
- Create a frame for attaching a box from a bar with a section of 5x5 cm, according to the attached diagram. In total, you will need 60 m of timber. Before assembly, it is important to treat the parts with a wood preservative to protect the material from precipitation and temperature extremes. Fasten the parts together with self-tapping screws for wood using metal corners 5x5 cm.
- Fix the box on the prepared stand and carry out further assembly on this inclined stand.
- Mark up where the pipes will go and where the pipes will fit. Color them black, too, so as not to increase heat loss.
- Cut the 0.5 '' thick reinforced plastic pipes into pieces to the desired length. To avoid making a mistake, use the first snippet as a reference. You should get 45 pieces of 2.14 m each.
- Assemble the snake from the pipes on the stand using fittings for metal-plastic pipes on the bends. A total of 44 angular elbows of the "mom-to-mother" and "mom-to-dad" type and 88 adapters from a metal-plastic pipe to a fitting are required. Use sealing thread to seal the joints. At the beginning and end of the snake, fasten the adapters for connecting the water supply and drainage hoses.
- Paint the structure black using a spray gun or can.
The collector coil is painted with black paint
- Connect the coil to the pump and make sure there is no leakage when pumping water. If any connection is not tight enough, drain the water and reassemble it, and then check again.
- Cover the top of the box with clear glass or solid polycarbonate. If it is not possible to use a solid sheet, make an aluminum frame in the size of the available fragments (preferably no more than four) and secure the panels securely. Carefully treat each joint with transparent silicone so that the water heater is airtight.
According to the described scheme, a collector with a capacity of 1.6-2 kW is assembled.
To reduce the cost of the device, a flexible XLPE pipe is used. It is originally black and is mounted with a snake using only two fittings. But in this case, the water will not come into contact with the hygienic metal (as in the described case), but with the plastic. This is undesirable if the water is also intended for cooking.
Video: how to make a flat copper tube solar water heater
Solar collector installation
The device is installed on the roof. This option is suitable for both country houses and high-rise buildings. It is better if the roof is pitched and the angle of inclination is close to the latitude of this region. In this case, you will need to attach the brackets to the boards on its southern side through the roofing material. The collector will be placed 15–20 cm above the roof level, parallel to the ramp. This is the most harmonious solution, especially if several water heaters are used in the house. Sometimes the collector is recessed into the roof so that the protective screen is flush with the decorative roof covering. But this method is much more expensive and can weaken the roof structure.
It is best to mount the flat-plate collector system on a pitched roof
On flat roofs, the collectors are mounted on special structures that hold them at a given angle. Stands can be purchased ready-made or welded independently from the corners. The metal structure is attached to the base with large anchor bolts.
On a flat roof, the collectors are mounted on special structures
In summer cottages, solar collectors are installed next to the house or pool in an open sunny area. In this case, they choose a place on an already created site or equip a reliable base separately. To do this, you will need a rectangular platform with a compacted bulk cushion, waterproofing and a coating of paving slabs, porcelain stoneware, and other durable, hard and weather-resistant material. Subsequently, a metal or wooden easel stand is mounted on it, on which the solar collector is attached.
Installing a solar collector on supports that do not have a common base is considered less reliable, but it helps to save space.
Solar collector maintenance
Like any other equipment, the device requires service. The most common works:
If the collector was purchased, at the first breakdown it is worth calling the master, and during the warranty period - contact the manufacturer's representative. A homemade solar water heater will have to be repaired on its own, but finding a breakdown and fixing it in a home-made product is much easier than in a factory one. The experience of collector repairmen suggests that you first need to check the condition of the valves, sensors, storage tank and pump, since they are less reliable than the solar plant itself.
In DHW systems with a solar collector, valves and sensors most often fail.
Video: instructions for assembling a solar collector from aluminum cans
The owners of solar collectors are sure: once you evaluate the capabilities of this device, it will simply be impossible to do without it. Now you can provide your house or summer cottage with cheap and safe heat.
Every year, the problem of providing your country house or summer cottage with hot water becomes more and more urgent. Especially often the owners of the cottages in which they live permanently reflect on this problem. After all, the cost of heating and hot water supply takes a significant share in financing the life support of the home. And the search for opportunities to reduce the cost of maintaining a house is a normal and natural desire of any person. Of course, the most realistic option is to reduce the cost of heating a house, to study and start making devices from the field of alternative energy with your own hands.
The fact that a selective renewable energy device used for heating a house has many undeniable advantages has been known for a long time, and almost every adult knows about it. However, in practice, not every one of these adults, who want to become more autonomous in matters of water heating, decides to shell out a decent amount of money to purchase a factory-made selective home heating device. Of course, you can find a way out of any situation, and even more so from this. You can make a solar collector for heating a house with your own hands. You can easily assemble a flat, air solar collector yourself. These self-made solar water heating devices can be made from beer cans and plastic bottles by connecting them with a hose and vacuum tubes. As a result, you will get an absorber of solar energy for heating your house by heating water, the manufacture of which will require almost no financial investment from you (especially when choosing the option from cans).
What materials will you need to make a homemade absorber
It seems to the average man in the street that it is incredibly difficult to make a solar-powered absorber for heating your home on your own, having carried out your own production of every detail that makes up the device. However, in order to make such an absorber, which will act as a device for heating water in the heating system of a house, you do not need to purchase or search for some exotic materials. You don’t have to go around a bunch of stores looking for the right hose, looking for vacuum tubes. Do not worry - this is all speculation of lazy people and people who are afraid to get down to business. The main thing is to take a balanced approach to solving the problem, plan everything correctly, draw a diagram and select the necessary materials.
A homemade Selective Coated Flat Air Absorber can be made from common HDPE materials and components. Polycarbonate vacuum tubes and other parts can be purchased at low prices at any hardware store or supermarket. The assembly diagram is quite simple; for training purposes, you can watch a video on the World Wide Web (there are more than enough such videos). In fact, on the global network, you can find a lot of specialized literature on this problem. If you decide to do the intended work at a high-quality level, reading a certain amount of literature will not be superfluous.
The main difficulty in the assembly process is how exactly to make the coil (this is a tube in a tortuous shape through which fluid circulates, carrying out the accumulation of energy). There are several options based on which the assembly diagram will be drawn up. The easiest option is to assemble an absorber based on a ready-made coil (you can try to look for something suitable for these purposes, it is important that it is vacuum). Alternatively, the circulation system located on the back of the refrigerator may be suitable. The second option is to pick up the necessary vacuum tubes, two or three hoses, a couple of plastic water bottles (the coolant is collected from them). Watch the tutorial video again for more confidence. It is better to use copper pipes for heating water. Next, you need to do the soldering of the coil itself.
The second very important element that goes into the absorber is the upper side made of transparent polycarbonate. In industrial conditions, polycarbonate coating is not used, the front coating is cast from a tempered glass alloy. However, in our case, a homemade air manifold is considered, the thermal circuit and the required efficiency of which allows the use of polycarbonate, since we will assemble the device from available inexpensive materials. It is worth noting that there are assembly schemes where materials are used from beer cans to the use of plastic bottles.
Preparing to assemble the absorber
So, in assembling your device, you'd better resort to using cellular transparent polycarbonate. The use of this type of polycarbonate will allow you to achieve maximum heating efficiency from the device being created. It is also worth making a choice in favor of this polycarbonate because it is very durable. This is important, considering possible weather disasters, such as large hail, hurricane air flow that rips branches from trees - these accidents must be taken into account, as they can damage weak coverage. The honeycomb structure of the coating will help you create an airy greenhouse effect, resulting in an increased moment of heating the water in the tubes. Simply put, by using this material and in addition to selective coating, you will significantly increase the efficiency of the product.
For an absorbent panel, you will need a sheet of metal that is about 0.8 millimeters thick (copper is better, however). In principle, steel sheet will do. The outer surface will need to be coated with a so-called selective coating (paint with matte black paint, the paint must be resistant to high temperatures). If you do not follow these recommendations (black coating is also meant), the device will not function in the correct mode.
In addition to the listed components, purchase the mineral wool necessary for thermal insulation, it will create a kind of air trap, minimizing heat exchange with the surrounding space, transferring all the heat to the coil, and then through the hose to the heating system of the house.
You can also assemble the body of the device yourself, for this you need to use aluminum materials or use a less durable but easier to process wood material. Working with wood, you will spend significantly less time creating a heater, and plywood is even easier to work with. But still, it is better to use an aluminum frame, its durability, in comparison with wood, cannot be compared in any way.
Determining the size of the collector
Now let's summarize, we list all the materials necessary for assembling an effective home-made collector:
- Copper tubes with dimensions of 18 millimeters - from which you will form a coil (the same tubes are used when assembling heating systems);
- matt black paint, resistant to high temperatures (with its help you will apply a selective coating);
- mineral wool (thermal insulation);
- sheet of metal (copper, iron, steel), sheet thickness 0.8 millimeters in thickness;
- corner transitions 18 x 18 millimeters;
- plumbing transitions 18 mm x ¾ (needed in order to connect to the water supply system);
- cellular polycarbonate (collector front cover);
- aluminum sheet and aluminum corners to create the product body, if there are none - wooden planks and a plywood sheet for the rear wall of the heater;
- all the tools necessary for soldering work.
It is important to determine in advance the dimensions of your collector based on its dimensions, calculate in advance the required number of pipes, transitions and other materials (in other words, the overall performance of the mounted device). Calculate the amount of water that will be required to provide heat exchange throughout the system. To do this, decide in advance for what purposes the collector will be used - either it is just washing dishes, or for a shower, or to ensure that all household needs of hot water supply in your home are covered. To heat water for washing dishes or taking a shower, it will be enough to assemble a collector measuring 200 x 100 centimeters, the distance between the tubes in the coil should be from 8 to 10 centimeters.
DIY solar collector assembly process
The beginning of the assembly of this solar energy product starts with the manufacture of the coil. If you can find a complete coil, the final assembly will take much less time. The selected coil should be very thoroughly washed under running water (preferably hot) in order to wash out all blockages from the inside and get rid of freon residues. If you have not found suitable tubes, then you can purchase the required amount in the store. But in this case, you will have to make the coil itself. To make it, cut the tubes to the required length. Next, using corner transitions, solder them in the form of a coil structure. Further, so that the collector can be connected to the water supply system, solder plumbing transitions with dimensions ¾ to the edges of the coil. There are several options for the shape and design of the coil, for example, you can solder the tubes in the form of a "ladder" (if you are going to implement this option, then buy non-angular transitions, you will need tees).
Then, on a pre-prepared sheet of metal, you apply a selective coating with black matte paint, it is advisable to do this in at least a couple of layers. Wait for the airflow to dry the paint and start soldering the coil (unpainted side). The entire coil structure must be soldered along the entire length of the tubes, by doing this, you guarantee the most efficient heat exchange and, as a result, the maximum transfer of heat to the water supply system. If you do everything correctly, the solar collector you assembled will work as intended.
Responsible assembly stage
The final step is to assemble the case, which will hold all the components of the device together into a single structure. Using a sheet of plywood and wood blocks, knock down a sturdy box. In the used wooden blocks, cut the grooves in advance, into them you then insert a polycarbonate screen (the groove depth is about 0.5 cm). Tubing outlets can be made after all major components have been installed. Next, in an already assembled wooden box to create an air pocket, you put mineral wool insulation. Fasten a panel with a coil on top of the mineral wool. Tuck the edges of the cotton so that the coil does not touch the walls of the box. The heating panel and the polycarbonate panel must also have a distance between them and not touch each other.
The final stage consists in treating the case with a special solution with a water-repellent ability and covered with enamel (except for the front part).
That's all, the solar collector is ready with your own hands. In order to activate it, place it on a support structure, facing the sun in such a way that the rays fall on the front at the most right angle. Install a water storage tank on the roof; it will serve as a reservoir. From the top of the tank, run the hose from the top pipe of the manifold to the bottom of the bottom pipe. By connecting the water according to this scheme, you will ensure operation in the natural circulation mode. According to the laws of physics, hot water will rise up towards the tank, and the displaced cold water will enter the manifold for heating in the coil. Do not forget that a hose and a valve must be connected to the tank for taking water from the tank, as well as filling it with a new one.
A solar collector is an alternative source of heat energy through the use of solar. Now this convenient device is no longer an innovation, but not everyone can afford to install it. If you calculate, the purchase and installation of a collector that will satisfy the household needs of the average family can cost five thousand US dollars. Of course, the payback of such a source will have to wait for a long time. But why not make a solar collector with your own hands and install it?
The standard device is in the form of a metal plate, which is housed in a plastic or glass case. The surface of this plate accumulates solar energy, retains heat and transfers it for various domestic needs: heating, heating water, etc. There are several types of integrated manifolds.
Cumulative
Storage collectors are also called thermosyphon collectors. Such a solar collector with your own hands without a pump is the most profitable. Its capabilities allow not only to heat water, but also to maintain the temperature at the required level for some time.
Such a solar collector for heating consists of several tanks filled with water, which are located in a heat-insulating box. The tanks are covered with a glass lid, through which the sun's rays break through and heat the water. This option is the most economical, easy to operate and maintain, but its efficiency in winter is practically zero.
Flat
P is a large metal plate - an absorber, which is located inside an aluminum case with a glass cover. A flat solar collector with your own hands will be more effective when using a glass cover. Absorbs solar energy through hail-resistant glass, which transmits light well and practically does not reflect it.
There is thermal insulation inside the box, which can significantly reduce heat loss. The plate itself has a low efficiency, therefore it is covered with an amorphous semiconductor, which significantly increases the rate of thermal energy accumulation.
When making a solar collector for a pool with your own hands, it is often a flat integrated device that is preferred. However, he copes with other tasks just as well, such as: heating water for household needs and heating the room. Flat is the most widely used option. It is preferable to make an absorber for a solar collector from copper.
Liquid
From the name it is clear that it is the liquid that acts as the main coolant in them. A do-it-yourself solar water collector is made according to the following scheme. Through a metal plate that absorbs solar energy, heat is transferred through pipes attached to it to a tank with water or antifreeze liquid or directly to a consumer.
Two pipes fit the plate. Through one of them, cold water is supplied from the tank, and through the second, the already heated liquid enters the tank. The pipes must have inlet and outlet openings. This heating scheme is called closed.
When heated water is supplied directly to meet the needs of the user, such a system is called open-loop.
Unglazed ones are more often used to heat water in a pool, therefore, assembling such thermal solar collectors with your own hands does not require the purchase of expensive materials - rubber and plastic will do. Glazed ones have higher efficiency, so they are able to heat the house and provide the consumer with hot water.
Air
Air devices are more economical than the above analogs that use water as a heat carrier. The air does not freeze, leaks or boils like water. If a leak occurs in such a system, it does not cause so many problems, however, it is rather difficult to determine where it happened.
Self-production is not expensive for the consumer. The solar panel, which is covered with glass, heats the air between it and the thermal insulation plate. Roughly speaking, it is a flat collector with a space for air inside. Cold air enters inside and warm air is supplied to the consumer under the influence of solar energy.
The fan, which is mounted in the duct or directly on the plate, improves circulation and improves air exchange in the device. The fan requires the use of electricity, which is not very economical.
Such options are durable and reliable and easier to maintain than devices that use a liquid as a heat carrier. To maintain the desired air temperature in the cellar or to heat the greenhouse with a solar collector, just such an option is suitable.
How it works
The collector collects energy using a light storage or, in other words, a solar-receiving panel, which transmits light to a storage metal plate, where solar energy is converted into thermal energy. The plate transfers heat to the coolant, which can be both liquid and air. Water is sent through pipes to the consumer. With the help of such a collector, you can heat a home, heat water for various household purposes or a pool.
Air collectors are mainly used for heating a room or heating the air inside it. The savings when using such devices are obvious. Firstly, there is no need to use any fuel, and secondly, electricity consumption is reduced.
In order to get the maximum effect from the use of the collector and to heat the water for free for seven months a year, it must have a large surface and additional heat exchangers.
Engineer Stanislav Stanilov presented the world with the most versatile solar collector design. The main idea of using the device developed by him is to obtain thermal energy by creating a greenhouse effect inside the collector.
Collector design
The design of this manifold is very simple. Basically, it is a solar collector made of steel pipes welded into a radiator, which is placed in a wooden container, protected by thermal insulation. Mineral wool, polystyrene foam, polystyrene can be used as heat-insulating material.
A galvanized metal sheet is placed on the bottom of the box, on which the radiator is mounted. Both the sheet and the radiator are painted black, and the box itself is covered with white paint. Of course, the container is covered with a glass lid, which is well sealed.
Materials and parts for manufacturing
To build such a homemade solar collector for heating a house, you will need:
- glass that will serve as a cover. Its size will depend on the dimensions of the box. For good efficiency, it is better to select glass with a size of 1700 mm by 700 mm;
- a frame for glass - you can weld it yourself from the corners or put together from wooden planks;
- board for the box. Here you can use any boards, even from the dismantling of old furniture or a plank floor;
- rolling corner;
- coupling;
- pipes for assembling a radiator;
- radiator clamps;
- galvanized iron sheet;
- inlet and outlet pipes of the radiator;
- a tank with a volume of 200-300 liters;
- aquacamera;
- thermal insulation (sheets of polystyrene, expanded polystyrene, mineral wool, ecowool).
Stages of work
Stages of making a Stanilov collector with your own hands:
- A container is hammered out of the boards, the bottom of which is reinforced with beams.
- A heat insulator is placed on the bottom. The base must be especially carefully insulated to avoid heat leakage from the heat exchanger.
- After that, a galvanized plate is arranged at the bottom of the box and a radiator is installed, which is welded from pipes, and fixed with steel clamps.
- The radiator and the sheet under it are painted black, and the box is painted white or silver.
- The water tank should be installed under the collector in a warm room. It is necessary to arrange thermal insulation between the water tank and the collector to keep the pipes warm. The tank can be placed in a large barrel, into which expanded clay, sand, sawdust, etc. can be filled. and thus insulate.
- Above the tank, an aquacamera must be installed in order to create pressure in the network.
- Do-it-yourself installation of a solar collector should be carried out on the south side of the roof.
- After all the elements of the system are ready and installed, you need to connect them into a network with half-inch pipes, which must be well insulated in order to reduce heat loss.
- It would be nice to build a controller for the solar collector with your own hands, since the factory devices are not in operation for long.
Sizing calculation
Calculation of dimensions in order to make a solar collector for heating with your own hands, first of all, is aimed at determining the load of the heat supply system, the coverage of which is assumed by this device. It goes without saying that this implies the use of several energy sources in the complex, and not just the energy of the sun. In this matter, it is important to arrange the system in such a way that it interacts with others - then this will give the maximum effect.
To determine the area of the collector, you need to know for what purposes it will be used: heating, heating water, or both. After analyzing the water meter data, heating needs and insolation data of the area in which the installation is planned, the collector area can be calculated. In addition, it is necessary to take into account the needs for hot water of all consumers that are planned to be connected to the network: a washing machine, a dishwasher, etc.
Selective coating performs perhaps the most basic function in the operation of the collector. A coated plate or radiator attracts many times more solar energy, converting it into heat. You can purchase a special chemical as a selective coating, or you can simply paint the storage tank black.
To make your own selective coating for solar collectors, you can apply:
- special ready-made chemical;
- oxides of various metals;
- thin heat-insulating material;
- black chrome;
- selective paint for the collector;
- black paint or film.
Collectors from scrap materials
Assembling a solar collector for heating a house with your own hands is cheaper and more interesting, because it can be made from various materials at hand.
Of metal pipes
This assembly option is similar to the Stanilov manifold. When assembling a solar collector from copper pipes with your own hands, a radiator is cooked from the pipes and placed in a wooden box, laid from the inside with thermal insulation.
Copper pipes will be the most effective, aluminum can also be used, but they are difficult to cook, but steel pipes are the most successful option.
Such a homemade manifold should not be too large to be easy to assemble and install. The diameter of the pipes for solar collectors for welding a radiator must be smaller than that of pipes for the inlet and outlet of the coolant.
From plastic and metal-plastic pipes
How to make a solar collector with your own hands, having plastic pipes in your home arsenal? They are less effective as a heat accumulator, but they are several times cheaper than copper and do not corrode like steel.
The pipes are laid out in a spiral box and secured with clamps. They can be overpainted with black or selective paint for better performance.
You can experiment with pipe laying. Since the pipes do not bend well, they can be laid not only in a spiral, but also in a zigzag pattern. Among the advantages, plastic pipes are easily and quickly soldered.
From the hose
To make a solar collector for a shower with your own hands, you will need a rubber hose. The water heats up very quickly in it, so it can also be used as a heat exchanger. This is the most economical option when making a collector with your own hands. The hose or polyethylene pipe is placed in a box and secured with clamps.
Since the hose is twisted in a spiral, there will be no natural circulation of water in it. To use a water storage tank in this system, it must be equipped with a circulation pump. If this is a summer cottage and a little hot water leaves, then the amount that will flow into the pipe may be enough.
From cans
The heat carrier of the solar collector from aluminum cans is air. Banks are connected to each other, forming a pipe. To make a solar collector from beer cans, you need to cut off the bottom and top of each can, dock them together and glue them with a sealant. Finished pipes are placed in a wooden box and covered with glass.
Basically, the solar air collector made from beer cans is used to eliminate dampness in the basement or to heat the greenhouse. As a heat accumulator, you can use not only beer cans, but also plastic bottles.
From the fridge
Do-it-yourself solar hot water panels can be built from an unusable refrigerator or radiator of an old car. The condenser removed from the refrigerator must be rinsed well. Hot water obtained in this way is best used for technical purposes only.
Foil and a rubber mat are spread at the bottom of the box, then a capacitor is placed on them and fixed. To do this, you can use belts, clamps, or the fastener with which it was attached in the refrigerator. To create pressure in the system, it does not hurt to install a pump or an aquacamera above the tank.
Video
You will learn how to make a solar collector with your own hands in the following video.