Making household items, tools and electrical appliances with your own hands is not always associated with a desire to save money. The spirit of invention lives in almost everyone who has ever held a wrench or screwdriver in their hands. For those who are not able to throw in the trash a single gram of copper wire and even an old unnecessary razor blade, it will be useful to find out how a workable boiler can be made from such improvised items.

A do-it-yourself boiler can be made different ways, but not all options for self-assembly of this device allow you to use it for a long time. The article describes the main, time-tested options for self-manufacturing a boiler.

How to make a boiler with your own hands - the best of proven methods

Most often, in artisanal conditions, boilers are made from:

• Razor blade. Blades Satellite.
• Nails.
• TENA for a teapot.

TEN from an old kettle

TEN from an old kettle

It is also possible to make at home workable devices for heating water from nichrome wire, which is installed on a ceramic insulator.

The main task that must be performed when designing heating elements independently is to minimize the possibility short circuit and electric shock. When using low-voltage homemade products, electric shock is practically not worth fearing, but devices powered by 220 V can cause accidents and fires.

Blade boiler

It is not difficult to make a boiler from razor blades. To perform the work, it is necessary to prepare the following components:

• 2 blades of the "Satellite" type.
• 2 matches.
• Twin wire with plug.
• Threads.

Scheme of an electric boiler made of blades

The process of assembling a homemade boiler is as follows:

• A copper strand of electrical wire is tied to each blade.
• 2 matches are placed between the blades, which will serve as spacers to protect against short circuits.
• The blades are threaded to the matches in such a way as to prevent the free movement of metal parts.

Homemade hot water device assembly

A homemade blade boiler is completely ready for use!

Testing a homemade device

Now it remains only to pick up a tank in which it will be possible to boil water. The container to be used with a boiler of this design must not be made of conductive material. You should also exercise extreme caution when turning the device on and off. Before you turn on a home-made electrical device in a 220 V network, you must first lower the device into the water. During water heating, it is strictly forbidden to touch an electrical device or a container with water.

In addition to the necessary safety measures, it must also be remembered that heating water in this way is possible only if it contains conductive metal salts. Distilled water with a blade boiler will not heat up, due to the lack of a conductive medium between the two metal planes.

In addition, the use of an electrolytic method of heating water negatively affects its taste, so this heating option is most suitable for technical liquids.

Boiler from heating element

Making a boiler at home from a heating element is no more difficult than using razor blades. This version of a home-made device, if properly manufactured, is safer to use.

The heating element is not difficult to "get" from, the malfunction of which is not related to the heating element.

In addition to having a working heating element, you will also need to prepare a two-wire wire with a plug, which can also be borrowed from a faulty kettle. Also, for attaching wires to the heating element, it is recommended to purchase terminal blocks, the use of which will greatly simplify and speed up the process of self-manufacturing the device. In this case, the assembly process is carried out in the following sequence:

• The ends of the wire are stripped of insulation using a knife or a special device.
• The wires are brought into the terminals and then fixed on the terminals of the heating element with built-in screws.
• Using a multimeter, the resistance of the heating element is checked, as well as possible leakage to the product case.

Water heating device from a heating element from a kettle

With a successful diagnosis homemade device can successfully compete with factory products, and the quality of the connection between the main wire and the heating element can even be better than that of store-bought household appliances. The absence of soldered connections will allow this device to last much longer, but if there are no terminal blocks available, then the above-described boiler manufacturing option can be made by soldering wires to the contacts of the heating element.

This version of a homemade boiler can be used without any restrictions. The quality of boiled water prepared in this way allows you to brew tea, coffee or any other drinks without losing taste.

From nails

The electric nail appliance is a variation of the blade boiler, but with a more "civilized" design. To make this water heater, you need to prepare:

• 6 nails 80 mm.
• Two-wire copper wire with a plug.
• Electric drill and drill 3 mm.
• Line segment wooden board 100x100 mm, at least 25 mm thick.

Nails for a homemade water heater

The process of making a boiler from nails is carried out in the following sequence:

• In the middle of the wooden plate, 6 holes with a diameter of 3 mm are made with a distance of 3-5 mm between them.
• A steel nail is inserted into each hole in the wooden plate.
• From a cable with a plug, each contact is connected to 3 nails.
• A wooden plate is installed above the tank and is connected to a 220 volt network.

When carrying out these actions, it is necessary to strictly ensure that the wires are pressed as tightly as possible to the metal surface nails. To ensure reliable contact of the wires with the electrodes, it is recommended to insert 1/3 of the copper strands of the wire into each hole, before installing the nails into the wooden plate. If all the steps were done correctly, then when checking the resistance between the contacts of the plug, the multimeter should show a zero value.

Use this device for heating water in the following sequence:

1. Pour water into a non-metallic mug, which should not be distilled.
2. Place a wooden plate on the mug with the electrodes facing down.
3. Connect the device to the 220 V network.
4. After the liquid boils, the homemade boiler should be disconnected from electricity.

As in the case of using a razor blade product, the quality of the boiled liquid leaves much to be desired, therefore this way boiling water is also best used for technical needs.

The most powerful homemade boiler

Nichrome spiral

In order to boil a large volume of water, you can make a powerful portable device from improvised means. For the manufacture of the device you will need the following parts:

1. Nichrome spiral with a wire diameter of at least 1 mm.
2. Industrial fuse series PN 2.
3. Two-core cable from a wire with a cross section of at least 4 mm 2.
4. Screwdriver and wood screws 20 mm.
5. Collapsible type plug.

Fuse PN-2

The manufacture of a powerful device for heating water is carried out in the following sequence.

1. The PN-2 fuse is disassembled to remove the ceramic body of the product.
2. 8 self-tapping screws, which were formed during the disassembly of the device, are screwed into the holes in the body of the ceramic insulator.
3. The end of a nichrome spiral clings to one of the 8 screwed screws.
4. Then, inside the body of the electrical insulator, the spiral is pushed to the opposite end of the round insulator and again fixed around the screw.
5. The spiral turns in the opposite direction, but is already fixed to another screw screwed into the insulator.
6. In the same way, the spiral and self-tapping screws are connected at 5 more points, after which stripped copper wires are connected to the first and last self-tapping screws and the self-tapping screws are completely screwed into the ceramic insulator. Given the significant power of such a homemade boiler, the cross section of the connected copper wire must be at least 4 mm 2. A plug is installed on the other end of the wire.

Checking a powerful homemade water heater

The boiler may only be operated in a suspended state. The heating element must be completely lowered into the water and must not touch the walls and bottom of the tank. When using a homemade one, it is strictly forbidden to touch the container and the body of the device while heating the water.

Conclusion

A boiler from improvised means can be made by hand without financial costs. Without exception, all home-made products should be operated in such a way that the human body does not come into contact with the heated liquid or with the uninsulated part of the current-carrying elements. It is forbidden to leave the boiler, made by yourself, unattended, as well as in places where children can access the turned on device.

Build a heating boiler country houses, which are not connected to the central gas pipeline, it is quite possible even on their own. In this article, we will talk about how to make an electric heating boiler with your own hands. We will consider 3 available options for electric boilers - heating elements, electrode and induction.

What tools will be needed

To assemble homemade electric heating and to face it with a minimum of difficulties, you should have quality tools at your disposal.

For work you will need:

• welding machine - it is most convenient to work with inverter model;
• cutter - if you do not know how to use a gas cutter, it is better to use a plasma cutter;
• grinder - you will even need 2 models - a large one for a disk with a section of 230 mm and a small one for a disk with a section of 125 mm;
• electric drill;
• a hammer;
• core;
• roulette and compasses.

Electric boiler on heating elements

The scheme of an electric boiler with a do-it-yourself shade is the simplest to execute and has been known for quite a long time.

The principle of operation of the heating element boiler

The device of all household appliances in which heating elements (heaters) are installed is the same. When the power is turned on, voltage is applied to the heating element, which gradually heats up and transfers thermal energy to the liquid located around it.

The advantages of such devices:

• a wide range of heating elements of various shapes and capacities;
• possibility of use in any heating system with liquid heat carriers;
• insulation is installed on the boiler body, so that voltage is supplied exclusively to the heating element;
• do not require complex maintenance;
• the heating level is very easy to control, even with a minimum set automatic elements management.

Among the disadvantages of a home-made electric boiler of this type are:

• "gluttony" in the consumption of electricity, since 1 kW of power is required to heat 10 m 2 of area;
• impurities in the coolant accumulate on the heating element in the form of scale, so it needs to be cleaned about once a year;
• The heating element can only function in the presence of liquid, it is recommended to install an idle speed sensor with it.

The order of assembly of the boiler with heating elements by their rivers

Before you make an electric boiler with your own hands, you should take care of having a reliable power line. Only equipment with a power of not more than 6 kW can be connected to ordinary networks with a voltage of 220 V and a frequency of 50 Hz. If a more powerful boiler is required, a three-phase wiring and a separate input must be made for it.

So, we begin assembling a home-made electric heating boiler from a pipe with a cross section of 159 mm with a wall thickness of 10 mm. This pipe will serve as the body of the boiler. For it, you will need either a factory-made hemisphere with a cross section of 159 mm and a thickness of 10 mm, or sheet metal with a thickness of 8 mm or more of the same section.

The roof of the boiler, into which the heating elements will subsequently be embedded, can be made from a channel 8 mm thick.

We cut a coupling with a section of ¾ inch into the dome of the boiler. We will screw the drain valve into this coupling. In addition, you will need 2 pipes with a section of 1 inch for inflow and return. The thread on the nozzles can be done both internally and externally. It all depends on which one you prefer to work with.

To relieve excess pressure, it is necessary to prepare a branch pipe for the tie-in of the bypass channel. You will also need 3 adapters, into each of which a heating element for an electric boiler will be screwed. Another adapter will be needed for the temperature sensor. In addition, you will need holders for automation.

Please note that it is advisable to cut the threads on the pipes and adapters immediately.

Prepared threaded pipes, the same as on heating elements, must be immediately screwed into adapters. This is necessary so that the thread is not damaged during welding to the arch. To mark the places where the heating elements are inserted, the outer diameter of the pipe must be divided into 6 equal sectors according to the size of the radius. Then we draw three identical sectors strictly at an angle of 120 °.

The next step is to start cutting. Having finished with the markup, using a plasma cutter, we cut out holes for the nozzles for heating elements. They should be cut only along the outer contour. With all other nozzles, this does not matter in principle.

Let's start welding. We first intercept the pipes at several points so that they do not lead. Then we check the accuracy of the location, if necessary, lightly tap with a hammer, and then we perform a continuous seam. It is important that the adapters for heating elements in the electric boiler for heating with their own hands protrude 1 cm above the surface of the boiler roof.

We proceed to cutting the arch from the channel. In its center we make a hole for the air valve pipe, after which we weld the pipe itself. On the side we make a hole for the temperature sensor and also weld the pipe under it.

All protrusions, burrs and welding residues must be carefully cleaned with a grinder. The inner surface of the platform of the vault must be perfectly flat. The pipes for installing heating elements will only protrude from the outside by 1 cm.

We got a fairly powerful do-it-yourself electric boiler with 3 heating elements. If you need a simpler unit, according to the same principle, it can be assembled for 1 or 2 heating elements.

Assembling a heating boiler on electrodes

Devices of this type have been actively used only in the last 10-15 years. These are more technological devices, compared with heating elements.

Design

In electronic electric boilers the liquid acts as a heating element. A self-assembled electric boiler of this type is a metal case, inside of which there is an insulated steel electrode.

0 is applied to the body, and phase is applied to the electrode. When the voltage is applied, the water ions begin to oscillate at a frequency of 50 hertz. In this case, the liquid gradually heats up. Due to this property, such boilers are also called ion boilers.

The dimensions of the electrode boilers are small. They can be made from a pipe with a cross section of up to 320 mm and a length of up to 60 cm. However, an electric boiler for heating a house with your own hands can be made much smaller.

Advantages:

• small size, thanks to which the ion boiler can be placed even in a small apartment;
• the absence of the so-called "dry run", which guarantees the boiler's serviceability, since it will not work without liquid inside;
• resistance to voltage drops;
• high heating and cooling rate, which means easy adjustment;
• economy in electricity consumption in comparison with devices on heating elements.

Among the disadvantages of such boilers are the following points:

• an important condition for the effective functioning of the electrode boiler is the level of thermal conductivity and the quality of the coolant;
• the device must be reliably grounded, since there is a high risk of electric shock;
• it is important to exclude the possibility of air entering the system, otherwise the electrodes will become unusable due to corrosion.

Instructions for assembling a homemade electrode boiler

As a housing for an electric heating boiler with our own hands, we use a pipe with an internal section of about 50 mm and a length of 40 cm. In addition, you will need a solid rod with a diameter of 20 mm and a length of 30 cm, as well as two adapters with threaded internal threads. At the end of the rod, we drill a blind hole with a thread for a bolt Ø10 mm.

We prepare pipes. 1 we will weld at the end of the pipe, and the other at the side. In order for the side pipe to fit perfectly to the pipe, it is cut with a grinder, and then polished with a round file.

Cut holes for pipes. If there is no cutter, then many small holes can be drilled around the circumference. The work is brought to the ideal with a needle file and a round file. The hole for the side pipe must be located 10-15 mm from the edge of the pipe.

The next step is to weld the pipes to the pipe. To prevent them from being led, first they do spot welding in several places, and then they put a continuous seam.

We prepare the platform for the electric boiler. To do this, you can take a sheet of fiberglass 2 cm thick and cut a piece 120 × 120 mm with a hacksaw. Then in this platform it is necessary to drill one hole in the center, and four - around the perimeter. The cross section of the holes should be 10-12 mm.

Through the holes around the perimeter, the fasteners of the boiler body will be passed, and the central hole is designed to fix the steel electrode.

We proceed to fixing the body for the boiler on the platform. Four Ø12 mm nuts can be welded onto the housing on 4 sides to ensure a secure fit. Bolts Ø10 mm will easily pass through them.

Such nuts need to be welded with a slight indent from the platform. To ensure it, it is necessary to screw nuts of suitable size onto the bolts, thread them into wide nuts, and fix them again from below with smaller ones. Thus, it will be easier to perform welding work.

At the last stage, we perform the final assembly of the boiler. To do this, cut out a rubber gasket with a cross section slightly larger than the outer diameter of the boiler. In its central part, we make a hole and pass the electrode through it. Then we install the case on the platform and fasten it.

Boilers of induction type

Among all the options for assembling heating with an electric boiler with your own hands, making an induction type model is the most innovative.

The principle of operation of an electric induction boiler

If you omit the details, then the operation of the induction boiler is based on heating the coolant by means of a magnetic field.

Among the advantages of such units:

• high efficiency;
• safety;
• the possibility of using any coolant;
• lack of scale.

• high cost of factory boilers;
• the complexity of the structure of the automatic control unit. Without preparation, it will be difficult to assemble it.

Instructions for assembling a homemade induction boiler

It is worth noting that often the instructions on how to make an induction-type electric boiler are so complicated and contain such labor-intensive drawings that self-assembly of the equipment looks rather doubtful. However, we found a non-standard solution.

Before you make an electric boiler for heating yourself, you will need to purchase a 2.4 kW induction furnace and 3 meters of profiled pipes Ø25 × 50 mm with walls 2.5 mm thick.

If we consider how this design will work, then first we assemble flat container from the profile - liquid will move along it. And then we fix the induction stove to the pipe and connect it to the network. Everything together will look something like a saucepan on the stove.

Pipe cutting must be done as accurately as possible. It will take several pieces of 400 mm each, carefully cleaned of burrs at the ends.

Since the liquid inside such a boiler will move like a snake, it is advisable to take an even number of pipe pieces so that the inlet and outlet are located on the same side - it is more convenient to connect them to the heating circuit.

Because the profile pipes not perfectly even, they must first be docked with blunt edges with sharp ones and numbered so as not to be confused later.

At the next stage, the joints between the pipes must be boiled. We lay the structure on a flat surface, tighten it with a clamp and weld it. First, we do spot welding so that the structure does not lead, and then we perform capital seams.

Now we need to close the end part of our container. For this we use a steel strip cut from profiled pipes. We perform welding in a similar way - first pointwise, and then capitally.

On the opposite side, we also weld the strip, not forgetting to install the inlet and return pipes on the outermost pipes. To ensure the maximum contact area of ​​​​the container with the stove, all seams must be carefully cleaned.

So that our boiler can be hung on the wall, 2 corners must be welded on its back, into which the induction stove will be placed, as well as loops for hanging.

The last stage of work is painting. You can use heat resistant paint. On this assembly work completed. You can hang the boiler and connect it to heating and electricity.

When buying an induction oven, make sure that it is designed for continuous operation. Otherwise, you will need to restart the system every 2 hours.

Results

Each of the listed models is fully functional and reliable. Everyone will make their own choice in favor of any of them. The main thing is to carefully consider the work and, in case of difficulty, consult with knowledgeable people.

Do you want to save several thousand rubles? And that's true, when this skillful person refused such an opportunity. In this case, we will focus on the manufacture of an elementary instantaneous water heater. Surely in the summer many suffer due to lack of hot water in the country, and finances do not allow to buy a finished product. Or just feel sorry for the money. If you have the necessary skills and ingenuity, then we suggest you try yourself as a local Kulibin.

How does an instantaneous water heater work?

Having a flowing water heater, in the country you can even take a light shower

Of course, we will not talk about the design of the equipment in as much detail as possible, since its internal structure was considered in another.

However, before we get started, let's brush up on the basic design elements.

As you know, the main part of the "protochnik" is the heating element. It is a spiral (or straight tube), which is placed in a sealed copper flask. Next, this flask is placed in the body of the device and heats the water flowing through it. The incoming liquid heats up instantly and flows out of the tap of the water intake point already warm.

TEN of a flowing water heater: buy or make

TEN instantaneous water heater

As you already understood, the most important task that you will have to break your head over is where to get the heating element for our future “protochnik”. We have 2 options:

1. Go to the store and buy a suitable heating element- it will cost you 500-700 rubles. This option, of course, is simpler and is suitable for people who do not want to rack their brains over how to solder a balloon with an element.

Before buying a heating element, decide on its permissible power, because the wiring in the apartment / house may not withstand if you are greedy and buy an element that is too powerful. The maximum for which ordinary apartment- 5 kW, and "Khrushchev" and even less (3-4 kW).

1. Make a heating element yourself. Of course, it will cost you less, because you will definitely not spend money on a purchase. However, this method will require you to have the following equipment and materials:

• Gas-burner
• Machine for soldering copper pipes
• Copper tubes
• Nichrome wire
• heat resistant fabric
• Heat Resistant Adhesive

Step 1. Spiral the copper tube. Ideally, the spiral should have 4 turns. Choose any shape of the coil that is convenient for you - a circle or a square. If in the future it will be more convenient to work with a square, then choose it. This does not affect the operation of the device in any way, but it will work much more conveniently.

Place the turns not close to each other, but at a distance.

Step 2. Now let's start winding the nichrome wire on a copper tube. You need to wind tightly so that the turns of nichrome touch each other. Tightly wound turns will hold tightly, however, for safety net and more reliable fixation, we advise you to fix the ends of the spiral with special heat-resistant glue. This is used in the manufacture of ovens.

Step 3. It would be best if you wrap the spiral with a heat-resistant cloth. If you didn’t manage to get this material, then it’s okay. Then you just need to make sure that no combustible substances get on the spiral itself. We are sure it will not be difficult with careful handling.

Step 4. Feed each of the spirals in a parallel circuit. This will allow you to get more power of the device than with a serial circuit.

Step 5. If desired, you can place the heating element in a sealed flask, brewing it with a burner, if one is at hand.

Calculation of the heating element of the water heater

After describing the general procedure, we will analyze in detail how many meters of nichrome wire and copper tube we will need, and also find out the approximate diameter of the turns of the heating element.

So, first, let's deal with the calculation of nichrome wire. Suppose, in a store or through an acquaintance, you got a wire of this material 1 mm in diameter.

First, let's remember that in order to be able to take a shower using our newfound water heater, its power must be at least 5 kW.

P=I*U; I=P/U=5000W/220V= 23 BUT.

That should be the current. Of course, ordinary wiring in an apartment is unlikely to withstand this, even if your wires are copper. Therefore, we will take care in advance of drawing a separate line for normal operation"protoka".

The resistance is calculated using the following formula:

R=p*L/S, where

P is the resistivity;

R is the electrical resistance of nichrome;

S is the cross-sectional area.

Also remember another basic formula, where R=U/I

Equate both parts and get:

By default, we know that the resistivity of nichrome is 1.1 Ohm * kV.mm./m.

We also calculate the cross-sectional area: S \u003d πr 2 \u003d 3.14 * 0.5 2 \u003d 0.8 sq. mm.

Since we plan to use the water heater at home,

220/23=1.1*L/0.8

L \u003d 8.8 / 1.4 \u003d 6.2 m. - the desired total length of the wire.

It turns out that by dividing the entire wire into 3 parts, we will have approximately 6.2 / 3 = 2 meters of nichrome wire for each segment.

Copper tube length calculation

Winding wire on a copper tube

In our calculations, we will proceed from the fact that the copper tube is 10 mm in diameter with a wall thickness of 1 mm.

First, we calculate the circumference of one turn. It will be L=2πR= 2*3.14*5=31.4 mm.

Now let's divide the length of one piece of wire by the obtained value: 2000 mm / 31.4 cm = 64 - this is the number of turns that can be tightly wound on a copper tube.

And since the diameter of the wire is 1mm, that is, in fact, this is the winding step, the length of the wire in the wound state will be 64 * 1mm = 64 mm. Thus, a two-meter wire, when tightly wound on a copper tube 1 cm in diameter, will take only 6.4 cm. To be sure, we will round up to 7 cm.

We brought sample diagram calculation for one wire, however, for maximum efficiency, we have 3 of them, and we agreed to wind them in parallel, and not in series. This means that the distance between the turns of the first wound wire should be 2 mm.

It turns out that, having wound the first wire with a step of 2 mm, parallel to it, back to back, we start winding the second one. Similarly, we wind the 3rd: close to the 2nd.

In fact, it turns out that all three wires start in the same place, but with a shift of 1 mm.

Thus, it turns out that the length of the copper tube should be 7 cm * 3 = 21 cm.

During the twisting of a copper tube into a spiral, it can flatten at the bends, which will negatively affect its efficiency, and indeed its performance in general. Therefore, for convenience, we advise you to fill the tube with sand and close it at both ends with plugs (rubber inserts or cut a thread with a die / tap and screw screws inside).

Manufacture of instantaneous water heater

So, we have a heating element available (purchased or home-made - at your discretion). Now it remains to think out the further design of the instantaneous water heater.

We'll need bucket (pot), drill driver, rubber gaskets, union(fitting ½ or ¾ "), ball valve. We make several holes in the bottom for the best fixation of the heating element. For this, we will also need rubber gaskets, which should be placed inside the container.

Outside, the heating element is fastened with nuts and bolts.

The simplicity of the design lies in the fact that cold water should be immediately fed into the heating element spiral. Therefore, we make holes for the tube in the bottom of the tank, connect a drain fitting or fitting to it. Its size depends on the size of the thread of the pipe of the water supply system.

You can already connect a water riser to this fitting. We recommend installing a drain cock at the outlet of the pipe. In the future, it will be very convenient to connect a shower head to it, for example.

The internal structure of the heating element

Temperature regulator we also need. Anyone can play his role, even the simplest thermostat. You can take it from any broken electric kettle. In the kettle, the thermostat is designed together with the heating coil. We don’t need a heating element, we will throw it away, and we just need its part in the form of a thermostat and a power button.

It is mounted next to the heating element, which allows you to determine the current water temperature as accurately as possible. And the button for its control will be more convenient to place on the surface of the case.

As a result, we will get a small storage-flow water heater, which will heat 15 liters of water almost instantly.

Housing thermal insulation also won't be redundant. It will not only help keep hot water warm, but it will also protect you from accidental burns. As an outer case, you can use a larger container into which this tank can fit. Or you can build a kind of pallet from tin with edges where the tank will fit. At the same time, it is better to put the tank on wooden planks, and fill all the voids mounting foam or ecowool.

Safety rules when using a homemade water heater

Remember that a self-built device is nevertheless dangerous to use, because it has a minimum of protection against overheating, boiling over and electric shock. Therefore, you need to protect yourself as much as possible.

Be sure to ground your water heater! Since such products are most often needed in summer cottages, it is best to ground the boiler on land plot. To do this, you will need an iron frame: bury it in the garden. Let a steel tape go from her to the house.

The simplest design does not have any protective sensors to prevent overheating. Therefore, when using a homemade water heater, be as careful as possible and monitor the water level yourself!

Anyone can assemble an electric boiler with their own hands - by performance characteristics prefabricated units are not much inferior to factory products. With a responsible approach, a handicraft boiler can turn out to be even more reliable and durable than a factory-made machine.

This also applies to electric boilers for heating a private house, known for their efficiency and high performance. Parts for assembling such equipment are widely available, and the manufacturing process itself can be cheaper than buying a finished device.

Classification of homemade boilers

There are three types of electric boilers. The first option - working on heating elements. They are equipped with a tubular electric heater, which is heated by the action of electricity and transfers heat to the liquid. The heater is insulated so that the coolant is not energized.

The second option is the induction action. It is equipped with a winding transformer, with the heating pipe acting as an induction coil. Heating of the coolant occurs due to eddy currents that occur on the winding.

Finally, the third option, electrode - liquid is not only a coolant, but is also an integral part of the electrical system. It is quite simple to assemble an electrode boiler with your own hands, but high requirements are placed on the electrical safety of this equipment.

Design

In fact, a home-made electric boiler is a piece of pipe with built-in electrical fittings. This is very convenient, especially if you make the unit removable: then the care and maintenance of equipment will be greatly simplified.

If the unit is placed not in a pipe, but in a separate housing, then additional sensors can be installed that will automate the operation of the heating system, increase efficiency and reduce energy consumption. In addition, when it is necessary to replace the boiler with another, it will be possible to do this without violating the integrity of the system circuit.

Difficulties of operation

The disadvantage of any electric heater is the danger of exceeding the limit for connecting electrical equipment in a private house. Thus, the total power of all electrical appliances used in a dwelling should not be more than 15 kW.

To service a private house with an area of ​​​​about 100 m2, a unit with a capacity of at least 10 kW is required.

Therefore, by connecting an electric boiler with your own hands, you allocate only 5 kW of energy to the use of other devices. To increase the consumption limit, you need to obtain a special permit.

To make a homemade electric heating boiler with a tubular electric heater, you will need the following set of materials:

• steel sheet with a thickness of more than 2 mm;
• a piece of steel pipe (length and diameter depend on the performance of the unit);
• three-phase heating elements (it is not recommended to use heaters with a built-in relay, as they wear out quickly).

First, the future bottom of the boiler must be cut out of the steel sheet. The dimensions of the bottom must correspond to the diameter of the pipe. Then, from the same metal, it is required to make a flange - a ring whose inner diameter is equal to the outer or inner diameter of the pipe, depending on how the part is planned to be fixed to the body. The width of the ring is usually 30 mm.

Next, a cover with a diameter corresponding to the outer diameter of the flange is made from a steel sheet. The cover and flange are connected using 6 bolts, holes are pre-drilled at the mounting points of the fasteners. A few more holes are drilled in the lid - their size must correspond to the dimensions of the heating elements planned for installation.

The bottom must be welded to the boiler body first, the flange next. The cover is mounted only after the tubular heaters are firmly fixed on it. A sealing gasket made of a material resistant to water is inserted between the heating elements and the cover.

Between the cover and the flange is another gasket made from an automotive chamber. This gasket must be an exact copy of the flange, including holes for bolts in it.

Installation of nozzles

Before closing the boiler with a lid, pipes for connecting pipes of the heating system are mounted in its body, having previously cut out suitable holes. It is important that there are threads at the ends of the pipes: this is required to install inlet valves that will allow you to shut off the circulation of the coolant in the circuit if the electric boiler needs to be repaired. The pipe for the removal of hot liquid is located in the upper part of the unit, it is advisable to build it directly into the cover. The cooled coolant is fed through the pipe from below.

When the pipes are mounted, the boiler is completely assembled and connected to the network. Sometimes its design can change: for example, not only the cover, but also the bottom is mounted on the flange. The device is versatile and can be easily adapted to technical parameters home heating systems.

Electric installation work

During electrical work, the contacts of all heating elements of the boiler are connected to the block, and the neutral wire is connected to it. Sometimes the heating elements are immediately shorted to this wire without using a block.

The cross section of the wire core must correspond to the load that the heating elements create: then the home-made electrical unit will work without failures.

A phase wire passed through a circuit breaker is connected to the contact of each heater. The cable section is selected based on the load created by all the included heating elements at the same time.

All wires must be insulated, special attention must be paid to ensure that their bare parts do not come into contact with the metal cover of the boiler.

To make an induction boiler you will need:

• a piece of plastic pipe with thick walls;
• copper wire with a diameter of 7 mm;
• 15 A welding inverter.

To plastic pipe two pipes are fixed, having previously made the corresponding holes. Its internal space is completely filled with wire scraps 40-50 mm long.

Then an induction coil is created: the wire is carefully wrapped around the pipe, the total number of turns is about 90. The coil is connected to the inverter. The resulting home-made heating boiler is mounted directly into the pipeline, cutting out a section of the pipe.

Assembly of the electrode boiler

Just make an electrode heater. To do this, the master will need:

• iron pipe with a diameter of 57 mm or more with thick walls;
• a sheet of iron with a thickness of more than 2 mm;
• internal electrode with a diameter of 25 mm;
• gaskets made of paronite or rubber and connecting terminals.

As in previous cases, you need to start by attaching pipe fittings to the future boiler body. From one end, the pipes are welded to the unit, from the other they are threaded.

When making an electrode boiler with your own hands, a hole for a plug is drilled in the body. An electrode is attached to the latter, it is installed inside the boiler. At the final stage, a home-made case is welded by installing a lid and bottom cut from an iron sheet.

After cleaning the welds, it is necessary to check them for permeability. For this, the welding spots are covered with soapy foam, and pressure is applied inside the housing with an air press. Where bubbles appear, the boiler will leak. When all identified faults have been eliminated, the case can be treated with enamel paint.

The boiler will work properly if the water in the heating system of the house contains soda. The latter is added in order to increase the current strength: this indicator can be calculated by dividing the power of the unit by 220.

Those who want to make a heater with their own hands do not decrease: the prices for factory-made autonomous heating devices are not encouraging, and their declared characteristics often turn out to be overestimated compared to the real ones. It is useless to make claims: manufacturers always have an “iron excuse” - the efficiency of heating a room is highly dependent on its thermal properties. Cases when it was possible to “squeeze out” compensation from the manufacturer for the consequences of an accident that occurred due to the fault of their product are also rare. True, although it is not forbidden by law to make household heaters on your own, trouble through the fault of a homemade product will be a serious aggravating circumstance for its manufacturer and owner. Therefore, this article further describes how to correctly design and manufacture safe domestic heaters of several systems that are not inferior in thermal efficiency to the best industrial designs.

Constructions

Amateur craftsmen fence heaters often of a very intricate design, see photo in fig. Sometimes they are well made. But the overwhelming most of the home-made heating devices described in Runet have one thing in common: a high degree of danger they create, harmoniously combined with a complete mismatch of the expected specifications valid. First of all, this refers to reliability, durability and transportability.

Make a heater for the house, households. premises or hiking autonomous for summer cottages, tourism and fishing, the following systems are possible (from left to right in the figure):

• With direct air heating on natural convection - electric fireplace.
• With forced blowing of the heater - fan heater.
• With indirect air heating, natural convection or forced air - oil or water-air heater.
• In the form of a surface emitting thermal (infrared, IR) rays - a thermal panel.
• Fiery autonomous.

The latter differs from a stove, stove or hot water boiler in that it most often does not have a built-in burner / furnace, but uses the waste heat of heating and cooking appliances. However, the line here is very blurred: gas heaters with a built-in burner are on sale and are made independently. On many of them you can cook or heat food. Here at the end will also be described a fiery heater, which is not on wood, not on liquid fuel, not on gas and certainly not a stove. And others are considered in descending order of their degree of safety and reliability. Which, nevertheless, with proper execution and for the “worst” samples, fully comply with the requirements in household autonomous heating appliances.

Thermal panel

This is quite complex and time-consuming, but the safest and most effective type household electric heater: double-sided radiation thermal panel for 400 W in a room of 12 sq. m in concrete house heats from +15 to +18 degrees. The required power of the electric fireplace in this case is 1200-1300 watts. Consumption Money on the independent production thermal panel is small. Thermal panels work in the so-called. far (more distant from the red region of the visible spectrum) or long-wave IR, so the heat is soft, not burning. Due to the relatively weak heating of heat-radiating elements, if they are made correctly (see below), there is practically no operational wear of thermal panels, and their durability and reliability are limited by unforeseen external influences.

The heat-radiating element (emitter) of the thermal panel consists of a thin flat conductor made of a material with high electrical resistivity, sandwiched between 2 plates - plates of a dielectric transparent to IR. Thermal panel heaters are made using thin-film technology, and the linings are made of a special plastic composite. Both are not available at home, so many amateurs try to make heat emitters based on a carbon coating sandwiched between 2 glasses (pos. 1 in the figure below); ordinary silicate glass is almost transparent to IR.

Such a technical solution is a typical surrogate, unreliable and short-lived. A conductive film is obtained either from candle soot, or by spreading an epoxy compound filled with ground graphite or electrical coal on glass. The main disadvantage of both methods is the uneven film thickness. Carbon in amorphous (coal) or graphite allotropic modification is a semiconductor with high intrinsic conductivity for this class of substances. The effects characteristic of semiconductors are weakly manifested in it, almost imperceptibly. But with an increase in the temperature of the conductive layer, the electrical resistivity of the carbon film does not grow linearly, as in metals. Consequence - thin places are heated more strongly, burn out. The current density in the thicker ones grows, they also heat up, they also burn out, and the entire film soon burns out. This is the so-called. avalanche burnout.

In addition, the soot film is very unstable, it quickly crumbles on its own. In order to obtain the required heater power, up to 2 volumes of carbon filler must be added to the epoxy adhesive. In fact, it is possible up to 3, and if 5-10% by volume of a plasticizer - dibutyl phthalate - is added to the resin before the introduction of the hardener, then up to 5 volumes of filler. But the ready-to-use (not hardened) compound turns out to be thick and viscous, like plasticine or greasy clay, and it is unrealistic to apply it with a thin film - epoxy sticks to everything in the world, except for paraffin hydrocarbons and fluoroplast. You can make a spatula from the latter, but the compound will follow it with beds and lumps.

Finally, graphite and coal dust are very harmful to health (have you heard of silicosis in miners?) and extremely dirty substances. It is impossible to remove or wash their traces, soiled things have to be thrown away, they stain others. Anyone who has ever dealt with graphite grease (this is the same finely crushed graphite) - as they say, I will live, I will not forget. That is, home-made emitters for thermal panels need to be made in some other way. Fortunately, the calculation shows that the “good old”, proven for many decades and inexpensive nichrome wire is suitable for this.

Calculation

Approx. 8.5 W/sq. dm ik. From the “pie” of the thermal panel emitter, 17 watts will go in both directions. Let's set the dimensions of the emitter 10x7 cm (0.7 sq. dm), such pieces can be cut from the battlefield and cutting waste in almost unlimited quantities. Then one emitter will give us a room of 11.9 watts.

Let's take the heater power of 500 W (see above). Then you need 500/11.9 = 42.01 or 42 emitters. Structurally, the panel will represent a matrix of 6x7 emitters with dimensions without a frame of 600x490 mm. Let's throw it on the frame up to 750x550 mm - it passes in terms of ergonomics, it is quite compact.

The current consumed from the network is 500 W / 220 V = 2.27 A. Electrical resistance the entire heater - 220 V / 2.27 A \u003d 96.97 or 97 Ohms (Ohm's law). The resistance of one emitter is 97 Ohm / 42 \u003d 2.31 Ohm. The specific resistance of nichrome is almost exactly 1.0 (Ohm * sq. mm) / m, but what section and length of wire is needed for one emitter? Will the nichrome "snake" (pos. 2 in the figure) fit between 10x7 cm glasses?

Current density in open, i.e. in contact with air, nichrome electric coils - 12-18 A / sq. mm. At the same time, they glow from dark to light red (600-800 degrees Celsius). Let's take 700 degrees at a current density of 16 A/sq. mm. Under the condition of free IR radiation, the temperature of nichrome depends on the current density approximately by the square root. We will reduce it by half, to 8 A/sq. mm, we get the operating temperature of nichrome at 700 / (2 ^ 2) \u003d 175 degrees, it is safe for silicate glass. The temperature of the outer surface of the radiator in this case (excluding heat removal due to convection) will not exceed 70 degrees with an outer surface of 20 degrees - it is suitable both for heat transfer with “soft” IR and for safety if the radiating surfaces are covered with a protective grid (see below).

A rated operating current of 2.27 A will give a nichrome cross section of 2.27 / 8 \u003d 0.28375 square meters. mm. According to the school formula for the area of ​​a circle, we find the diameter of the wire - 0.601 or 0.6 mm. With a margin, we will take it 0.7 mm, then the heater power will be 460 W, because. it depends on its operating current squared. 460 W is enough for heating, 400 W would be enough, and the durability of the device will increase several times.

1 m of nichrome wire with a diameter of 0.7 mm has a resistance of 2.041 ohms (0.7 squared \u003d 0.49; 1 / 0.49 \u003d 2.0408 ...). To obtain the resistance of one emitter of 2.31 ohms, you will need 2.31 / 2.041 \u003d 1.132 ... or 1.13 m of wire. Let's take the width of the nichrome "snake" in 5 cm (1 cm margin from the edges). For the wrapping of 1 mm nails (see below), we add 2.5 mm each, for a total of 5.25 cm per branch of the snake. The branches will need 113 cm / 5.25 cm = 21.52 ..., let's take 21.5 branches. Their total width is 22x0.07 cm (wire diameter) = 1.54 cm. Let's take a snake length of 8 cm (1 cm margin from short edges), then the wire laying ratio is 1.54/8 = 0.1925. In the lousiest Chinese low-powered power transformers he is ok. 0.25, i.e. we have enough space for the bends and gaps between the branches of the snake. Phew, the fundamental issues have been resolved, you can move on to R & D (experimental design work) and technical design.

OKR

Thermal conductivity and transparency for IR silicate glass vary greatly from grade to grade and batch to batch. Therefore, first you will need to make 1 (one) emitter, see below, and test it. Depending on their result, you may have to change the diameter of the wire, so do not buy a lot of nichrome at once. At the same time, it will change rated current and heater power:

• Wire 0.5 mm - 1.6 A, 350 W.
• Wire 0.6 mm - 1.9 A, 420 W.
• Wire 0.7 mm - 2.27 A, 500 W.
• Wire 0.8 mm - 2.4 A, 530 W.
• Wire 0.9 mm - 2.6 A, 570 W.

Note: who is literate in electricity - the rated current, as you can see, does not change according to the square of the wire diameter. Why? On the one hand, thin wires have a relatively large radiating surface. On the other hand, with a thick wire, it is impossible to exceed the permissible IR power transmitted by the glass.

For testing, the finished sample is placed vertically, supported by something non-combustible and heat-resistant, on a fireproof surface. Then the rated current is fed into it from a regulated power supply (IP) of 3 A or more or LATR. In the latter case, it is impossible to leave the sample unattended all the time of testing! The current is controlled by a digital tester, the probes of which must be tightly compressed with current-carrying wires with a screw with a nut and washers. If the prototype is powered by LATR, the tester must measure the power alternating current(limit AC 3A or AC 5A).

First of all, you need to check how the glass behaves. If it overheats and cracks within 20-30 minutes, then the entire batch is probably unsuitable. For example, dust and dirt eat into used glass over time. Cutting them is sheer agony and the death of a diamond glass cutter. And such glasses crack at much weaker heating than new ones of the same grade.

Then, after 1-1.5 hours, the strength of the IR radiation is checked. Glass temperature is not an indicator here, because. the main part of the IR emits nichrome. Since you most likely will not find a photometer with an IR filter, you will have to check with your palms: they are held parallel to the emitting surfaces at a distance of approx. 15 cm from them for at least 3 minutes. Then, within 5-10 minutes, even soft heat should be felt. If the IR from the emitter starts to burn the skin immediately, we reduce the diameter of the nichrome. If after 15-20 minutes a slight burning sensation (as in the sun in the middle of summer) is not felt, nichrome should be taken thicker.

How to bend a snake

The emitter device of a homemade panel heater is given in pos. 2 fig. above; the nichrome snake is shown conditionally. Glass plates cut to size are cleaned of dirt and washed with a brush in water with the addition of any dishwashing detergent, then they are also washed with a brush under running clean water. "Ears" - contact lamellae 25x50 mm in size made of copper foil - are glued to one of the plates with epoxy glue or instant cyanoacrylate (superglue). Entry of the "ear" on the lining - 5 mm; 20 mm sticks out. To prevent the lamella from falling off until the glue has set, something 3 mm thick is placed under it (the thickness of the lining glass).

Next, you need to form the very snake of nichrome wire. This is done on a mandrel template, the scheme of which is given in pos. 3 and a detailed drawing in Fig. here. “Tails” for annealing the snake (see below) must be given from 5 cm. The bitten ends of the nails are ground to roundness on an emery stone, otherwise it will be impossible to remove the finished snake without crushing it.

Nichrome is quite elastic, so the wire wound on the template must be annealed so that the snake keeps its shape. This should be done in semi-darkness or low light. The snake is supplied with a voltage of 5-6 V from the IP for at least 3 A (this is what a refractory lining is needed on a tree for). When the nichrome glows cherry, the current is turned off, the threads are allowed to cool completely, and this procedure is repeated 3-4 times.

The next step is to press the snake with your fingers through the plywood strip superimposed on it and carefully unwind the tails wound on 2 mm nails. Each tail is straightened and formed: a quarter of the turn remains on the 2 mm nail, and the rest is cut flush with the edge of the template. The rest of the “tail” of 5 mm is cleaned with a sharp knife.

Now the snake must be removed from the mandrel, without bending it, and fixed on the substrate, ensuring reliable electrical contact between the leads and the lamellas. They are removed with a pair of knives: their blades are slipped from the outside under the bends of the branches on 1-mm nails, carefully pry off and lift the crimped thread of the heater. Then the snake is placed on the substrate and the leads are slightly folded, if required, so that they lie approx. in the middle of the slats.

Nichrome is not soldered with metal solders with an inactive flux, and the remains of an active flux can corrode the contact over time. Therefore, nichrome to copper is "soldered" the so-called. liquid solder - conductive paste; It is sold in radio shops. A drop of liquid solder is squeezed out onto the contact of the stripped nichrome with copper and pressed through a piece of plastic film with a finger so that the paste does not stick out from the wire. You can immediately press down with some kind of flat weight instead of a finger. The weight and film are removed after the paste has hardened, from an hour to a day (the time is indicated on the tube).

The "solder" has frozen - it's time to assemble the emitter. Along the middle, we squeeze out a thin, not thicker than 1.5 mm, “sausage” of ordinary construction silicone sealant onto the snake, this will prevent the wire bends from slipping and closing. After that, the same sealant is squeezed out with a roller already thicker, 3-4 mm, along the contour of the substrate, stepping back from the edge approx. by 5 mm. We put on a cover glass and very carefully so that it does not slip sideways and does not pull the snake along with it, press down until it lies tightly, and put the emitter to dry.

The drying rate of silicone is 2 mm per day, but after 3-4 days, as it may seem, it is still impossible to take the emitter further into work, you need to let the inner roller fixing the bends dry. It will take approx. a week. If a lot of emitters are already made for a working heater, they can be dried in a pile. The bottom layer is laid out polyethylene film, it is also covered from above. Elements next. layers are laid across the underlying ones, etc., separating the layers with a film. The stack, for a guarantee, dries 2 weeks. After drying, the excess silicone that has come out is cut off with a safety razor blade or a sharp mounting knife. Silicone sagging must also be completely removed from the contact lamellas, see below!

Mounting

While the radiators are drying, we make 2 identical frames from hardwood slats (oak, beech, hornbeam) (pos. 4 in the figure with a panel heater diagram). Connections are made with a half-tree tie-in and fastened with small self-tapping screws. MFD, plywood and wood-based materials on synthetic binders (chipboard, OSB) are not suitable, because prolonged heating, albeit not strong, is categorically contraindicated for them. If you have the opportunity to cut frame parts from textolite or fiberglass - generally excellent, but ebonite, bakelite, textolite, carbolite and thermoplastic plastics are unsuitable. Before assembly, wooden parts are impregnated twice with a water-polymer emulsion or a water-based acrylic varnish diluted by half.

Finished emitters are placed in one of the frames (pos. 5). The overlapping lamellae are electrically connected by drops of liquid solder, as are the bridges on the sidewalls, which form serial connection all emitters. It is better to solder lead wires (from 0.75 sq. mm) with ordinary low-melting solder (eg POS-61) with inactive flux paste (composition: rosin, ethyl alcohol, lanolin, see on the vial or tube). Soldering iron - 60-80 W, but you need to solder quickly so that the emitter does not stick.

The next step at this stage is to impose a second frame and mark on it where the lead wires fell, you will need to cut grooves under them. After that, we assemble the frame with emitters on small self-tapping screws, pos. 6. Take a closer look at the location of the attachment points: they should not fall on live parts, otherwise the fastener heads will be energized! Also, to prevent accidental contact with the edges of the lamellas, all ends of the panel are pasted over with non-combustible plastic with a thickness of 1 mm, for example. PVC filled with chalk from cable ducts (wiring boxes). For the same purpose, and for greater structural strength, silicone sealant is applied to all glass joints with frame parts.

The final steps are, firstly, the installation of legs with a height of 100 mm. A sketch of the wooden leg of the panel heater is given in pos. 7. The second is the application of a protective steel mesh made of thin wire with a mesh of 3-5 mm to the sidewalls of the panel. The third is the design of the cable entry with a plastic box: it contains contact terminals, a light indicator. Perhaps - a thyristor voltage regulator and a protective thermal relay. Everything, you can turn on and warm up.

Thermopicture

If the power of the described thermal panel does not exceed 350 W, a picture heater can be made from it. To do this, foil isol is applied to the back side, the same one that is used for thermal insulation. Its foil side should be facing the panel, and the porous plastic side should be out. The front side of the heater is decorated with a fragment of photo wallpaper on plastic; thin plastic - not so hot what an obstacle to IR. In order for the heating picture to warm better, it must be hung on the wall at an angle of approx. 20 degrees.

What about foil?

As you can see, a homemade panel heater is a rather laborious task. Is it possible to simplify the work by using, say, aluminum foil instead of nichrome? Foil thickness of baking sleeve approx. 0.1 mm, it seems to be already a thin film. No, the point here is not the thickness of the film, but the resistivity of its material. For aluminum, it is low, 0.028 (Ohm * sq. mm) / m. Without giving detailed (and very boring) calculations, we will indicate their result: the area of ​​​​a thermal panel for a power of 500 W on an aluminum film 0.1 mm thick turns out to be almost 4 square meters. m. Still, the film turned out to be thick.

12 V

A homemade fan heater can be quite safe in a low-voltage, 12 V version. Power over 150-200 W cannot be achieved from it, too large, heavy and expensive, you will need a step-down transformer or power supply. However, 100-120 W is just enough to keep a small plus in the basement or cellar all winter, which guarantees against frozen vegetables and jars of homemade preparations bursting from frost, and 12 V is the voltage allowed in rooms with any degree of danger of electric shock. More can not be served in the basement / cellar, because. they are electrically dangerous.

The basis of the heater-fan heater for 12 V is an ordinary red working hollow (hollow) brick. One and a half thickness of 88 mm is best suited (top left in the figure), but a double thickness of 125 mm will also work (in the same place below). The main thing is that the voids are through and the same.

The device of a "brick" 12 V fan heater for the basement is given in the same place in fig. Let's count the nichrome heating coils for it. We take a power of 120 W, this is with some margin. Current, respectively, 10 A, heater resistance 1.2 Ohm. On the one hand, the spirals are blown. On the other hand, this heater should work unattended for a long time in rather difficult conditions. Therefore, it is better to turn on all the spirals in parallel: one will burn out, the rest will be extended. And it is convenient to regulate the power - just turn off 1-2-several spirals.

There are 24 channels in a hollow brick. The spiral current of each channel is 10/24 \u003d 0.42 A. Not enough, nichrome needs very thin and, therefore, unreliable. This option would fit for a household fan heater up to 1 kW or more. Then the heater must be calculated, as described above, for a current density of 12-15 A/sq. mm, and divide the resulting wire length by 24. 20 cm are added to each segment for 10 cm connecting "tails", and the middle is twisted into a spiral with a diameter of 15-25 mm. With "tails" all the spirals are connected in series with the help of copper foil clamps: its tape 30-35 mm wide is wound in 2-3 layers on folded nichrome wires and twisted for 3-5 turns with a pair of small pliers. To power the fans, you will have to install a low-power 12 V transformer. Such a heater is well suited for a garage or warming up a car before a trip: like all fan heaters, it quickly warms up the middle of the room without wasting heat on heat loss through the walls.

Note: computer fans are often called coolers (lit. - coolers). In fact, the cooler is the whole cooling device. For example, a processor cooler is a finned heatsink in a block with a fan. And the fan itself is also a fan in America.

But back to the basement. Let's see how much nichrome is needed for a reduced to 10 A / sq. mm for reasons of reliability current density. The cross section of the wire, clearly without calculations - 1 sq. mm. Diameter, see calculations above - 1.3 mm. Such nichrome is on sale without difficulty. The required length for a resistance of 1.2 Ohm is 1.2 m. And what is the total length of the channels in the brick? We take one and a half thickness (weighs less), 0.088 m. 0.088x24 \u003d 2.188. So we just need to pass a piece of nichrome through the voids of the brick. It is possible through one, because channels, according to the calculation, 1.2 / 0.088 = 13, (67), i.e. 14 is enough. So the basement is heated. And it is quite reliable - such a thick nichrome and strong acid will not corrode soon.

Note: the brick in the body is fixed with small steel corners on the bolts. In a powerful 12 V circuit, an automatic protective device, eg. automatic plug for 25 A. Inexpensive and quite reliable.

IP and UPS

It is better to take (make) a transformer on iron for basement heating with powerful winding taps for 6, 9, 12, 15 and 18 V, this will allow you to adjust the heating power over a wide range. 1.2 mm nichrome with blowing will also pull 25-30 A. To power the fans, then you need a separate winding for 12 V 0.5 A and also a separate cable with thin cores. To power the heater, wires from 3.5 square meters are needed. mm. A powerful cable can be the crappiest - PUNP, KG, 12 V leaks and breakdowns can not be feared.

Maybe you do not have the opportunity to use a step-down transformer, but lay around impulse block power supply (UPS) from an unusable computer. Its 5 V channel is enough for power; the standard is 5 V 20 A. Then, firstly, you need to recalculate the heater to 5 V and the power of 85-90 W so as not to overload the UPS (the wire diameter comes out 1.8 mm; the length is the same). Secondly, to supply 5 V, you need to connect together all the red wires (+5 V) and the same number of black wires (GND common wire). 12 V for fans is taken from any yellow wire (+12 V) and any black one. Thirdly, you need to short the PC-ON logic start circuit to a common wire, otherwise the UPS simply will not turn on. Usually the PC-ON wire is green, but you need to check: remove the casing from the UPS and look at the designations on the board, from above or from the mounting side.

heating elements

For heaters. types you will have to buy a heating element: 220 V electrical appliances with open heaters are extremely dangerous. Here, sorry for the expression, you need to think first of all about your own skin with property, whether there is a formal ban or not. With 12-volt devices it is easier: according to statistics, the degree of danger decreases in proportion to the square of the ratio of supply voltages.

If you already have an electric fireplace, but it does not heat well, it makes sense to replace a simple air heating element with a smooth surface in it (pos. 1 in the figure) with a ribbed one, pos. 2. The nature of the convection will then change significantly (see below) and the heating will improve when the power of the finned heating element is 80-85% of the smooth one.

A cartridge heater in a stainless steel case (pos. 3) can heat both water and oil in a tank made of any structural material. If you take one, be sure to check that the kit includes gaskets made of oil-thermo-petrol-resistant rubber or silicone.

The copper water heating element for the boiler is supplied with a tube for the temperature sensor and a magnesium protector, pos. 4 which is good. But they can only heat water and only in a stainless steel or enameled tank. The heat capacity of oil is much less than that of water, and the body of the copper heating element will soon burn out in oil. The consequences are severe and fatal. If the tank is made of aluminum or ordinary structural steel, then electrocorrosion due to the presence of a contact potential difference between metals will very quickly eat the protector, and after that it will eat through the body of the heating element.

T. naz. dry heating elements (pos. 5), like cartridge heating elements, are capable of heating both oil and water without additional protection measures. In addition, their heating element can be changed without opening the tank and without draining the liquid from there. The only drawback is that they are very expensive.

Fireplace

You can improve an ordinary electric fireplace, or make your own efficient one based on a purchased heating element, using an additional casing that creates a secondary convection circuit. From an ordinary electric fireplace, firstly, the air goes up in a rather hot, but weak jet. It quickly rises to the ceiling and heats through it more the floor of the neighbors, the attic or the roof than the master's room. Secondly, the IR going down from the heating element in the same way heats the neighbors from below, the underground or basement.

In the design shown in Fig. on the right, downward IR is reflected into the outer casing and heats the air in it. The thrust is further enhanced by the suction of hot air from the inner casing, which is less heated from the outer one in the narrowing of the latter. As a result, the air from the electric fireplace with a double convection circuit comes out in a wide, moderately heated jet, spreads to the sides, not reaching the ceiling, and effectively heats the room.

Oil and water

The effect described above is also given by oil and water-air heaters, which is why they are popular. Oil heaters of industrial production are sealed with non-replaceable filling, but it is by no means recommended to repeat them on your own. Without an accurate calculation of the volume of the housing, internal convection in it and the degree of filling with oil, a housing rupture, power failure, oil spillage and fire may occur. Underfilling is just as dangerous as overfilling: in the latter case, the oil simply tears the body under pressure when heated, and in the first case it boils first. If, however, the body is made of a deliberately larger volume, then the heater will heat disproportionately weakly compared to electricity consumption.

In amateur conditions, it is possible to build an oil or water-air heater open type with expansion tank. The scheme of its device is shown in fig. Once upon a time, they made quite a lot of them, for garages. The air from the radiator is slightly heated, the temperature difference between inside and outside is kept to a minimum, which is why heat losses are reduced. But with the advent of panel heaters, oil homemade products are coming to naught: thermal panels are better in every respect and are quite safe.

If you still decide to make yourself an oil heater, keep in mind that it must be reliably grounded, and you need to fill it only and only with very expensive transformer oil. Any liquid oil gradually bituminizes. Raising the temperature speeds up this process. Engine oils are designed to circulate oil through moving parts under the influence of vibrations. Bituminous particles in it form a suspension that only pollutes the oil, which is why it has to be changed from time to time. In the heater, nothing will prevent them from depositing soot on the heating element and in the tubes, which is why the heating element overheats. If it bursts, the consequences of oil heater accidents are almost always very severe. Transformer oil is expensive because the bituminous particles in it do not settle into soot. There are few sources of raw materials for mineral transformer oil in the world, and the cost of synthetic oil is high.

fiery

Powerful gas heaters for large rooms with catalytic afterburning are expensive, but record-breaking economical and efficient. It is impossible to reproduce them in amateur conditions: you need a microperforated ceramic plate with platinum coating in the pores and a special burner made of parts made with precision precision. At retail, one or the other will cost more than a new heater with a guarantee.

Tourists, hunters and fishermen have long come up with low-power afterburner heaters in the form of an attachment to a camp stove. These are also produced on an industrial scale, pos. 1 in fig. Their efficiency is not so hot, but it is enough to heat the tent until lights out in sleeping bags. The design of the afterburner is rather complicated (pos. 2), which is why factory tent heaters are not cheap. Fans of these also make a lot, from tin cans or, for example. from automotive oil filters. In this case, the heater can work both from a gas flame and from a candle, see video:

Video: portable oil filter heaters

With the advent of heat-resistant and heat-resistant steels in wide use, lovers of outdoor activities increasingly prefer gas camping heaters with afterburning on a grid, pos. 3 and 4 - they are more economical and heat better. And again, amateur creativity combined both options into a combined type mini-heater, pos. 5., able to work both from a gas burner and from a candle.

A drawing of a home-made mini-heater for afterburning is shown in fig. on right. If it is used occasionally or temporarily, it can be made entirely from cans. For an enlarged version for giving, jars of tomato paste, etc. will go. Replacing the perforated mesh cover significantly reduces warm-up time and fuel consumption. A larger and very durable option can be assembled from car rims, see next. video clip. This is already considered a stove, because. you can cook on it.

Video: heater-stove from a rim

From a candle

A lighting candle, by the way, is a fairly strong source of heat. For a long time, this property of hers was considered a hindrance: in the old days, at balls, ladies and gentlemen were bathed in sweat, makeup flowed, powder was lumpy. How after that they also twisted cupids, without hot water supply and shower, modern man difficult to understand.

The heat from a candle in a cold room is wasted for the same reason that a single-circuit convection heater does not heat well: hot exhaust gases rise too quickly and cool down, giving soot. Meanwhile, it is easier to make them burn out and give heat than a gas flame, see fig. In this system, the 3-circuit afterburner is assembled from ceramic flower pots; baked clay is a good IR emitter. A candle heater is intended for local heating, for example, so as not to shiver while sitting at a computer, but the heat from just one candle gives surprisingly much. It is only necessary, using it, to slightly open the window, and when going to bed, be sure to extinguish the candle: it also consumes a lot of oxygen for combustion.