It is extremely difficult to imagine a comfortable home without a heating system, because the presence of heat in the room depends on its presence and functionality. Such a system necessarily includes a heating boiler, the main task of which is to heat the coolant to a given temperature. There are many types of equipment, the main difference of which is the type of fuel used, which determines the principle of operation of the device. According to statistics, the most common heating boilers are solid fuels, which are considered one of the first heating devices.

How does such a unit work?

Solid fuel devices use various types of solid fuel for their operation. These are firewood, coal, oil shale, peat, etc. The boiler operating cycle can be divided into three phases. Let's look at each of them in more detail.

Stage #1 - ignition of the boiler

The cycle begins with ignition, which is characterized by a sharp increase in temperature on average from 40°C to 600°C in 5-10 minutes. The temperature values ​​of the combustion heat exchanger begin to increase, which depend on the system parameters and can range from 40°C to 70°C. At a minimum, a thermal shock is possible on the heating system as a whole and on the heat exchanger itself. The latter, especially those made of cast iron, will not be able to withstand such conditions for long and will burst. If the circulation rate of the coolant is low and heating occurs quickly, boiling of the liquid may occur, which will lead to thermal and hydraulic shock to the heating system. The most vulnerable to it are plastic pipes. At this stage, the pipes begin to warm up, but the air in the room is still cold.

Coal, firewood, pellets, peat, etc. can be used as fuel for solid fuel boilers.

Stage #2 - warming up the coolant

The temperature in the furnace continues to rise and reaches values ​​of 1300°C for coal boilers and about 1000C for wood boilers. The coolant continues to warm up. At this stage, control is important, otherwise it can heat up to the maximum boiler temperature, which remains 95°C, and this is already dangerous.

Regulation is carried out using a valve that controls the air supply. The optimum temperature must be maintained until the fuel is completely burned. During this phase, the pipes in the room become hot and the air warms up.

Stage #3 - fuel burnout

At the end of the boiler operating cycle, the fuel is completely burned out and smoldering coals are formed. The temperature drops to 600°C-400°C, which are considered the most comfortable for the system. The coolant slowly cools down, and the air in the room also begins to cool down little by little. After smoldering coals have formed, the cooling process of air and coolant immediately accelerates.

Having examined all phases of operation of a solid fuel boiler, you can clearly see its main feature - temperature cycling. It is due to the need to add a new portion of fuel from time to time in order to minimize fluctuations in coolant temperature. To a greater extent, this problem is solved in automatic boilers, where there is an automated fuel supply and burner fan pressure. The rest need constant human monitoring and timely replenishment of fuel.

How does a solid fuel boiler work?

You need to understand that a solid fuel boiler is a modular structure assembled in a steel casing, which includes the following components:

• Combustion chamber equipped with a door. This is where the fuel combustion process takes place.
• Grate. Fuel is placed on it and evenly distributed. After it burns out, the resulting ash is poured through special holes into the ash pan.
• Cleaning hatch. Designed for cleaning the boiler.
• Heat exchanger. It is a structure that transfers energy from a heated coolant to a cold one. Most often this is a barrel through which smoke pipes are laid. Gases passing through them heat up the coolant circulating in the heat exchanger.
• Thermostat for the boiler, allowing you to regulate the rate of fuel combustion.

In addition to the above mandatory elements of the device, they can also be equipped with equipment that significantly facilitates their operation. For example, such as draft regulator, gas burners, thermostatic valve. Read on for more details about each of them.

A schematic diagram of the structure of a solid fuel boiler is shown in the figure.

Traction regulator indispensable for adjusting the temperature inside the supply pipeline and controlling air access into the combustion chamber. When heated, the device expands and can affect the damper, opening or, conversely, closing it when the equipment cools. Boilers equipped with such a regulator can operate in automatic mode. The device is installed on the front wall of the equipment. When starting the boiler, it is regulated so that the temperature does not fall below 65°C and does not rise above 90°C.

Gas-burner runs on natural or liquefied gas and provides many advantages:

• Ignition takes only a few seconds.
• Safe to use.
• Simple design, which ensures the reliability of the equipment.
• Possibility of combination with different types of boilers.
• Operation in enclosed spaces.

Thermostatic valve designed for emergency heat removal from the boiler in case of overheating. To cool the apparatus, the hot coolant is drained from the system, rather than cold water being pumped in its place. The cooling circuit for steel equipment is installed inside the device, and for cast iron equipment - on the supply.

Using a gas burner allows you to get almost instant ignition and safety in using the device. This burner can be installed in any type of boiler

Types of devices based on the principle of fuel combustion

There are several types of heating boilers that run on solid fuel. Let's look at them in more detail.

Option #1 - classical combustion boilers

The equipment has a large firebox in which fuel combustion occurs naturally. The design, as a rule, contains a coolant temperature sensor-controller with the function of mechanical adjustment of the air damper. Such boilers are characterized by extreme simplicity of design, which makes their cost relatively low and operation very easy. In addition, they are very unpretentious to the type and quality of fuel and can be heated with coal, wood, briquettes, etc. However, classic devices also have disadvantages:

• Short burning time. As practice shows, one fill of fuel can be enough for a maximum of eight hours of operation.
• Difficulty in automating heating modes.
• Lower efficiency than other types of solid fuel boilers, which leads to high fuel consumption.
• A suboptimal combustion process leads to increased ash content.

Of all the listed disadvantages, the problem of frequent fuel loading can be leveled out. It is partially solved by installing a heat storage tank, which accumulates heat and thereby smoothes out temperature changes in the coolant. The tank is a metal container with good thermal insulation. Its volume is calculated depending on the capacity of the heating system and the power of the equipment. However, its presence means additional costs and the risk of system breakdown.

Traditional classical combustion boilers are very undemanding in terms of fuel. However, due to their design features, their efficiency is lower than that of other devices, so they are characterized by high ash content and high fuel consumption

Option #2 - long-burning devices

These boilers do not have the disadvantages described above. There are two types of such devices - pyrolysis and “smoldering” type devices. Long burning differs from the classic one by the presence of two combustion chambers. The fuel begins to burn in conditions of oxygen deficiency. When exposed to high temperatures, it begins to emit wood gas, which is a mixture of carbon monoxide, propane, methane and hydrogen. This process is called pyrolysis. At the end of this process, the fuel enters the second chamber, where it is burned with excess oxygen. As a result, the system efficiency increases to 90%.

The fuel burns with virtually no residue, and the ash has to be removed every few days. One download lasts an average of 12 hours. Average fuel consumption is low. The advantages of pyrolysis devices also include:

• Possibility of maintaining a given coolant temperature.
• Work on various types of solid fuel: coal, briquettes, firewood.
• Wide possibilities for automating combustion control systems.

The disadvantages of the system include the higher cost of equipment, energy dependence and demands on the level of fuel moisture.

Pyrolysis boilers are distinguished by the presence of two combustion chambers. In the first, pyrolysis occurs, that is, the release of wood gas, and in the second, the actual combustion of the material occurs.

Devices of the “smoldering” type are distinguished by the presence of a water jacket built around the entire perimeter. The combustion process proceeds like a candle - from top to bottom. The process of slow smoldering of the upper part of the fuel and the large volume of the combustion chamber, and in some cases it reaches 100 liters, allows the combustion process to be extended over a long time.

The design of smoldering boilers is such that fuel ignited from above can burn without adding a new portion for quite a long time, sometimes up to several days

There are models that can “last” on one coal bed for five days. To this undoubted advantage of the device we can add a slightly lower cost than pyrolysis boilers. However, these devices are very demanding on fuel. It must be either top quality coal or wood with a moisture content of no more than 20%. It is also necessary to pay attention to the resin content in the fuel; if it is high, frequent cleaning of the system is inevitable and the automation will fail faster.

From our next article you will learn what types of braces there are, what are their pros and cons: .

Which brands should you prefer?

The most famous manufacturers of solid fuel boilers of the classical combustion type are:

• SAS. The company has more than 30 years of experience in the production of heating equipment. Produces more than nine models of boilers for various purposes.
• Aton. The manufacturer produces three series of devices TTK V, TTK and TRADYCJA. The first two modifications are completely energy independent, the latter is equipped with automatic control and supercharging.
• Galmet. A large number of variations of different power, designed to work on coal, firewood, briquettes, as well as combined models.
• SIME. The company offers two types of devices. The Solida brand range includes six boilers with power varying from 16 to 40 kW. The Solida Evolution model range is represented by five devices with a power range of 23-67 kW.

The average cost of such devices depends on the power and starts from 20 thousand rubles.

The most well-known manufacturers of pyrolysis boilers include:

• ATMOS. Models are produced for working on coal, wood or coal, pellets, combined, with the ability to install a gas burner.
• VERNER. The company produces VERNER V brand equipment, classic pyrolysis devices designed to work on biomass. In terms of power, there are two modifications: VERNER V45 and VERNER V25.

The cost of devices starts from 40 thousand rubles.

The most popular manufacturers of “smoldering” type devices:

• Stopuva. Models with power from 10 to 40 kW are available, burning wood or coal and firewood.
• Candle. Variations of different power are produced, using firewood, wood chips, peat, and briquettes as fuel.

The price of equipment starts from 40 thousand rubles.

Solid fuel boilers are reliable and practical devices. They make it possible to use almost any type of fuel, which is very convenient. The main disadvantage of classical combustion devices is the temperature differences of the coolant. However, long-burning modifications do not have it. This equipment can be fully automated, which makes it possible to use the device with maximum convenience.

Content

1. Types of hot water solid fuel boilers
2. Pros and cons of a solid fuel boiler
3. Technical characteristics of TT boilers

Introduction

For those living outside the city or just considering buying a country house, the heating problem is extremely acute. There is no main gas supply in 34.5% of settlements in Russia. There is also often no access to power grids when the village is new or when the house is built at a distance from power lines. Therefore, a solid fuel heating boiler is sometimes the only available option.

Let's try to figure out what hot water solid fuel boilers are, how they work and what they are. We will also consider their advantages and disadvantages, and the main technical characteristics. We hope this material will help you decide which one is better to choose for heating your home.

Types of hot water TT boilers

A solid fuel boiler is a heating device that uses the energy of burning solid fuel. Most often it is wood or coal. However, some manufacturers produce models that run on pellets and fuel briquettes.

Based on the type of solid fuel used, boilers are divided into:

• wood burning

  This category includes conventional wood-burning boilers. Their disadvantage is that wood has low heat transfer and burns out quickly. Therefore, it is necessary to add firewood to the firebox every 2-4 hours.

• coal

  Coal boilers operate on brown or black coal, anthracite, and coke. The heat transfer of coal is 2 times greater than that of wood, and besides, coal is more compact. One bookmark is enough for 8-10 hours.

• pellet

  They work on special granules - pellets. They have a high efficiency of 85-95%. Their significant disadvantage is the high cost of the devices themselves and the fuel for them.

• universal

  Can run on wood, coal or pellets to choose from. The efficiency of universal boilers is lower than that of those using one type of fuel. Manufacturers also produce two-furnace models. Each type of fuel has its own combustion chamber and its own heat exchanger.

Photo 1: Fuel pellets for a solid fuel boiler

Based on the material of the heat exchanger, they are divided into:

• cast iron

  The advantage of a cast iron heat exchanger is its high heat capacity and corrosion resistance. Such products will last 30% longer than their steel counterparts. The disadvantage of cast iron heat exchangers is their fragility and sensitivity to temperature changes. We also note that cast iron ones are 2-3 times heavier than steel ones, as a result of which even low-power models have to be installed on a concrete foundation.

• steel

  Boilers with a steel heat exchanger are 30-60% cheaper than their cast iron counterparts. The disadvantage of a steel heat exchanger is the formation of corrosion due to water condensate.

There are two methods of burning solid fuels: classical and pyrolysis. Depending on which method is used, all models are divided into two types:

• classic

  In classic boilers, the combustion process occurs naturally. They are characterized by simplicity of design and, as a consequence, low price. Their disadvantage is low efficiency (75-85 percent) due to incomplete combustion of fuel.

• pyrolysis (or gas generator)

  The peculiarity of these devices is that solid fuel and the gas it produces burn separately. This achieves greater efficiency compared to classical ones (about 85-92%). Such devices are much more economical and environmentally friendly than classic ones. about 1.5 times more expensive than traditional ones.

According to the loading method, solid fuel boilers are distinguished:

• with manual loading

  To maintain a constant heating temperature, it is necessary to manually add a new portion of solid fuel every 2-4 hours.

• with automatic loading

  The design of the heating system is complemented by bunkers for automatic fuel supply. Depending on the volume of the bunker and the amount of solid fuel in it, the battery life ranges from several tens of hours to one month.

Photo 2: Boiler with automatic fuel supply

According to the degree of dependence on electricity, they are divided into:

• non-volatile

  In volatile boilers, air is forced into the combustion chamber by a mechanical thermosyphon.

• volatile

  Volatile boilers use an electric fan to force air into the combustion chamber. This process is controlled by an electronic unit that requires connection to the electrical network.

We have figured out the classification, now let's look at the design and operating principle of a TT heating boiler. It consists of the following components and assemblies:

• Combustion chamber

  The fuel combustion process takes place in this compartment of the boiler;

• Heat exchanger

  This device is made of cast iron or steel. It transfers the energy of burning fuel to the coolant;

• Cleaning hatch

  There is a special hole in the ash pan. Ash and combustion waste are removed through it;

• Grate

  A metal grate between the combustion chamber and the ash pan on which the combustion process occurs. Ash falls through holes in the grate into the ash pan, from where it is then removed manually;

• Thermostat

  A mechanical or automatic device that regulates the intensity of combustion, and therefore the temperature of the coolant;

Photo 3: Construction of a wood-fired hot water boiler

The process of operating a boiler with a water heating circuit is very simple. Solid fuel is placed through the loading door into the combustion chamber. During the combustion process, the heat exchanger heats up and transfers energy to a coolant, such as water. The coolant circulates through the heating system to warm the room. Ash and other combustion waste accumulate in the ash pan.

Return to contents

Pros and cons of a solid fuel boiler

Any heating device has its advantages and disadvantages. Let's weigh the pros and cons of TT boilers. The advantages of solid fuel heating devices include:

• fuel availability

  Wood and coal rank first among the most common types of fuel in Russia and the post-Soviet space. Forests cover 46.5% of the territory of our country.

• low cost

  For many of us, the cost of a product is critical. The cost of solid fuel models is significantly lower than gas or electric ones.

  For example: A solid fuel boiler Dakon with a power of 24 kW costs 52,000 rubles, and a gas boiler of the same power costs 97,000 rubles.

• no dependence on the power grid

  There is no electricity supply in many villages and country houses. Therefore, this quality of solid fuel boilers comes in handy in this case.

• long service life

  With appropriate care and maintenance, timely cleaning and careful operation, the service life of solid fuel boilers reaches 30 years.

Photo 4: Solid fuel wood boiler in operation

We've sorted out the advantages, now let's talk about the disadvantages:

• the need for constant monitoring

  The fuel in the firebox burns out quickly. It is necessary to reload every 2-4 hours to maintain the required temperature in the room.

• complex and time-consuming care

  Maintaining a solid fuel boiler is not an easy task. It is necessary to promptly remove ash from the ash pan, and also clean the combustion chamber from soot. It is better to entrust complex work such as cleaning from scale, rust and tar deposits to professionals.

• low efficiency of solid fuel combustion

  Compared to fuels such as gas and diesel, solid fuels have low combustion efficiency. The combustion process leaves waste in the form of ash, while gas and diesel leave no waste.

• need for fuel storage

  Firewood and coal have quite impressive dimensions. It is necessary to equip a separate room for storing their supplies.

• inertia of the combustion process

  The main feature of solid fuel boilers is their high inertia. The combustion process cannot be quickly interrupted. The boiler will continue to heat the water in the heating system even if it is already overheated. One way to solve this problem is to install a heat accumulator (buffer tank).

A solid fuel boiler is a heating device that uses wood or coal as fuel. The main parts of the device are a firebox with a water jacket, smoke removal and temperature control systems. The firebox has double walls, between which the coolant (water jacket) circulates. As the fuel burns, the walls heat up, and so does the water. The warm liquid rises up, enters the heat pipe, passes through the heating system, gives off heat and returns back. As a result of fuel combustion, a lot of smoke is produced, which is discharged through pipes to the street. The temperature control and regulation system adjusts the intensity of air entering the firebox.

Types of solid fuel heating systems

Devices are divided depending on the type of fuel used, the principle of its combustion and the degree of energy dependence. There are units that run on traditional solid fuels: wood, coal, fuel briquettes, coke. They are loaded into the firebox manually and periodically added as they burn. Pellet boilers appeared relatively recently. The fuel for them is pellets or granules with a diameter of 4-10 mm, which are produced from waste from industrial production and logging companies: sawdust, shavings, twisted trunks and branches. A special production technology has made it possible to increase the heat release of pellets almost to the level of coal. Since the models that consume pellets are new, they are equipped with fuel supply systems, have automatic ignition and are classified as long-burning devices. Universal boilers operate on all types of solid energy carriers and are equipped with both mechanics and automation, which allows you to choose the best option in terms of price and performance.

Based on the principle of fuel combustion, a distinction is made between gradual process units that operate using top combustion technology, which ensures layer-by-layer gradual combustion of fuel. This allows you to increase the efficiency of the equipment and reduce losses by up to 20%, reducing the amount of combustion products. A pyrolysis or gas generator boiler produces heat through pyrolysis. Dry distillation of wood at 800 degrees produces coke, which serves as fuel. This technology contributes to an almost complete absence of waste and an increase in efficiency up to 90%.

The degree of energy dependence of the boiler is determined by the need to use additional energy resources. Some devices require an electrical connection to function fully. Modern electronics and automation cannot work without electricity. Non-volatile boilers have a traditional design and are controlled manually. Such models provide heating in non-electrified houses, country houses, etc.

Boilers can be classified according to the type of body material into cast iron and steel. Cast iron devices are not susceptible to water hardness, but are afraid of sudden temperature changes. They have a large mass, so the inertia of the system will be high. Due to the anti-corrosion properties of cast iron, they have a long service life, but are more expensive.

Advantages and disadvantages of solid fuel boilers

The advantages of this type of heating devices include environmental friendliness and availability of fuel without connecting to the power grid. The operating time and power of the system are easily controlled using fuel loading volumes. Modern units have a high degree of fire safety and do not use explosive substances for operation. Such a heating system allows you to significantly save on connecting to the gas network. The required power is calculated from the ratio - 1 kW boiler per 10 sq. m area.

Disadvantages usually include the need to regularly add fuel, during which a little smoke enters the room. Boilers need to be cleaned periodically. They reach maximum power rather slowly and cannot immediately stop supplying heat.

The process of designing and installing solid fuel heating differs from similar ones in that it has special requirements. Not only the characteristics of the boiler or furnace are taken into account, but also the safety rules and operating efficiency of the entire system. Knowledge of these nuances will help you do the heating of a private house using solid fuel: boilers, stoves and a chimney system.

Basic parameters of solid fuel boilers and stoves

Solid fuel heat supply is characterized by relatively low initial costs. There are affordable solid fuel home heating boilers on the market. However, the process of installing equipment and the entire system as a whole must be carried out according to certain rules.

Almost all solid fuel stoves and boilers for water heating have the same characteristics. Their knowledge and ability to correctly use information will help you choose the right equipment for heating your home. When choosing, you should pay attention not only to technical aspects, but also to workmanship. Heating boilers for homes using solid fuel must be made of special grades of steel. The thickness of the case is at least 2 mm. For the combustion chamber, heat-resistant steel with a thickness of 3 mm or more is used.

The advantage will be a guarantee from the manufacturer and seller of heating equipment. You also need to pay attention to the availability of a network of service centers for maintenance and repair. In order for reviews about solid fuel heating boilers to be only positive when choosing equipment, you should study the following parameters:

• Rated power. It is determined by preliminary heat supply calculations. To form a small reserve, heating a private house with solid fuel should have a power 15-20% more than the calculated one;
• Heat exchanger material. The most reliable are cast iron heating boilers using solid fuel. Their disadvantage is a high rate of inertia and possible destruction under strong mechanical stress. An alternative is lighter and cheaper models with a steel heat exchanger;
• Boiler type. In addition to classic direct combustion equipment, you can choose pyrolysis or long-burning boilers.

Often they make heating boilers using solid fuel with their own hands. But to do this work you need to choose the right manufacturing scheme and materials. The advantage of such designs is the ability to adapt the above parameters to a specific heating system.

All solid fuel air heating stoves are designed to use coal, wood, fuel briquettes or peat. Exceptions are pellet boilers, which differ in design and are intended only for pellets.

Solid fuel heating schemes

The installation of heating equipment is preceded by the selection of a circuit. The heating supply configuration, system operating parameters, as well as the type of coolant depend on it. In some cases, a steam heating scheme using solid fuel is advisable. But most often they choose water heating at home.

The choice is determined by the characteristics of the house - its area, heat losses and the required temperature conditions for heating. For uniform heat distribution, it is recommended to install a solid fuel heating boiler in a water circuit. If the area of ​​the house is small, you can use air heating. In rare cases, homemade steam heating boilers using solid fuel are used.

At the first stage of choosing an installation plan for a solid fuel heating boiler, it is difficult to decide on the type of heat supply. Currently, the most common types are the following:

• Water with natural circulation. Applicable for small private houses and cottages. This is due to the maximum possible length of the pipeline being up to 30 m. Even with a powerful solid fuel home heating boiler, the water circulation rate will be small;
• Water with forced circulation. For this type of heat supply, you can consider manufacturing a solid fuel heating boiler with a built-in pump. Thanks to this design, the heating area is significantly increased;
• Air. It can be implemented using special do-it-yourself solid fuel heating boilers, which have channels in their design for the circulation of warm air. An alternative is to install and duct systems to distribute heated air throughout the rooms of the house;
• Steam. It is used extremely rarely in autonomous heating due to the high cost of the equipment and the need for constant monitoring of the condition of the coolant. Most solid fuel steam heating schemes are designed for heating large buildings.

The best option for installing a home heating boiler using solid fuel is water heat supply with forced circulation. It has good performance and is inexpensive to maintain. You can also note a large number of schemes according to which you can independently calculate a solid fuel heating boiler.

In any heating system, regardless of the chosen scheme, safety elements must be present. For solid fuel boilers for water heating, these are air vents, drain and check valves.

Direct combustion boilers

The simplest design of a solid fuel heating boiler is the classic model. They consist of a combustion chamber, an ash pan, a heat exchanger and a chimney pipe. The transfer of thermal energy to water occurs due to the combustion of fuel in the firebox.

The advantage of such models is reliability and simplicity of design. To independently manufacture a solid fuel heating boiler of this type, you will need a minimum of tools and materials.

But along with positive qualities, these boilers have a number of disadvantages. The main one is high fuel consumption. Reviews of direct combustion solid fuel heating boilers indicate the need to constantly add firewood or coal. If this is not done, the temperature of the water in the pipes will inevitably decrease.

It should also be noted the following features of heating a private house with solid fuel using boilers of this type:

• Large indicator of inertia. The time for heating water in the pipes to the required temperature can range from 10 to 30 minutes, depending on the type of system and its characteristics;
• Problems with power regulation. As in solid fuel air heating stoves, this can only be done by limiting the air flow through the ash pan. Therefore, when designing a heat supply system, it is necessary to provide for the installation of safety devices;
• Low efficiency. Typically it is around 60-65%. This is due to the fact that some of the thermal energy escapes along with carbon monoxide through the chimney;
• Equipment. Steel and cast iron solid fuel heating boilers do not include a circulation pump, a safety group.

It is also worth noting the absence of a second circuit for hot water supply. As an alternative, you can consider the possibility of connecting a direct or indirect heating tank, if so provided for in the design. In this case, when calculating a solid fuel heating boiler, the installation of additional equipment should be taken into account.

In most cases, the design of a solid fuel heating boiler provides an operating time on one batch of wood or coal from 4 to 6 hours. The greater the combustion intensity, the shorter the time for one cycle.

Pyrolysis solid fuel boilers

To optimize fuel consumption and increase efficiency, they were developed using solid fuel. Despite the similarity of the processes occurring inside the structure, their operating principle differs from the described direct combustion models.

Such solid fuel boilers for water heating are also called gas generator boilers. Their operating principle is not based on the direct combustion of wood, but on the formation of a volatile mixture. With a relatively low temperature effect on firewood and with a minimal influx of oxygen, the process of smoldering occurs. As a result, so-called wood gas is formed. Rising through special channels, it enters the combustion chamber, where it mixes with the air flow and ignites.

The advantage of using gas-generator heating boilers for home heating using solid fuel is economical fuel consumption. On average, one batch of firewood is enough for 12-18 hours of work. In addition, pyrolysis cast iron heating boilers using solid fuel are characterized by the following qualities:

• Electrical connection. To operate efficiently, the boiler must be equipped with a fan or turbine (rare);
• Fuel quality. Before loading, the firewood must go through a drying stage. The optimal humidity for heating a private cottage with solid fuel should be 8-10%;
• Minimum volume of carbon monoxide. Most of them burn in the secondary chamber. Thanks to this, when calculating a solid fuel heating boiler, it is possible to provide a chimney of a smaller diameter. But it must be insulated, since there is a high probability of condensation forming on its surface;
• Fuel types. The design of a solid fuel pyrolysis heating boiler is made in such a way that logs, sawdust and wood waste can be used. It is important that they have the required level of humidity and do not contain foreign impurities.

To regulate the power of a do-it-yourself solid fuel heating boiler, you can connect a fan to the control unit. It will regulate the power of the device depending on the temperature indoors and outdoors. This way you can reduce fuel consumption and optimize heating performance.

You can improve the characteristics of a gas-generating homemade solid fuel heating boiler by lining its outer surface. This will reduce the thermal losses of the structure.

Long-burning solid fuel boiler

One of the alternatives to a pyrolysis heating boiler is long-burning models. This is a relatively new heating design, which is characterized by low fuel consumption and a long combustion period.

The classic installation scheme for a solid fuel heating boiler provides for significant heating of water in the heat exchanger. Currently, low-temperature systems are gaining great popularity. It is for such schemes that a long-burning boiler will be optimal. It differs from classic models in the absence of an ash pan and the method of supplying air to support the combustion process. Reviews of long-burning solid fuel heating boilers indicate their high efficiency and reliable operation.

Structurally, it consists of a large combustion chamber, occupying about 90% of the total volume of the boiler. Air is supplied through the upper pipe, which lowers under the influence of gravity as the fuel burns. In fact, a smoldering process occurs, due to which the temperature of the coolant does not exceed +70°C.

It will be useful for the consumer to know the following properties of a long-burning boiler:

• Availability of automatic traction control. This is a mechanical device that has a thermoelement in its design. When it heats up, the air flow decreases. The reverse process provokes a decrease in the temperature of action on the thermoelement;
• No electrical connection required;
• Ash removal is carried out once every 3-4 days of operation.. However, with a large amount of combustion products, a sharp deterioration in the operation of the boiler occurs;
• Combustion occurs only at the top. Thanks to this, there is a significant reduction in fuel consumption.

One of the disadvantages of long-burning boilers is their high cost. However, with proper design of the heating system, compensation of primary costs will occur after 4-5 heating seasons. It is also necessary to ensure that the structure is protected from moisture.

A rational owner always thinks about how to wisely invest money in purchasing a solid fuel boiler for a private home and reduce the costs of its further operation during the heating season. Which one is better, more profitable, more convenient? This article will tell you what heating boilers exist, their types, advantages and disadvantages.

Types of solid fuel boilers for a private home

Prices for electricity and gas are rising from year to year, and it is not always possible to connect to the main line. Thus, a solid fuel boiler can be considered a reliable, autonomous and economical option for heating a home. With its pros and cons.

Home heating boiler

For convenience, all existing boilers that operate on solid fuel can be divided as follows:

1. Boilers in which fuel is supplied automatically to the firebox are pellet solid fuel boilers. They run on solid granular fuel. Pellet boilers are often classified as long-burning boilers.
2. Boilers that require manual fuel loading. They can also be divided into groups:

• classic or traditional boilers;
• top combustion pyrolysis boilers;
• long burning boilers.

The general parameter by which boilers are usually selected is the fuel combustion time for one load, as well as the type of fuel on which they operate effectively.

Solid fuel boiler with hob

When choosing a solid fuel boiler for heating a cottage or private home, you should pay attention to the following parameters:

• number of working circuits. A double-circuit boiler will heat the room and provide hot water;
• the presence of a hob will help solve the problem of cooking;
• boiler power and its efficiency. A boiler with a power of 5-12 kW can heat a house with an area of ​​100 square meters. m;
• dimensions, weight and ease of installation;
• boiler design and fuel loading method;
• fuel used.

Advice. Solid fuel boilers are produced only as floor-standing ones; it is impossible to hang such a boiler on the wall.

Classic solid fuel boilers

This is the most common type of boiler. Made from cast iron or heat-resistant steel. Heat is generated by burning solid fuel. Solid fuel boilers operate on coal, wood, peat, and heating pellets. Used for heating and also for heating water. Most often they are heated with coal, since wood burns quickly. The temperature sensor is responsible for maintaining the temperature in the boiler and regulates the air damper. When the temperature drops, the sensor opens the damper slightly and vice versa.

Classic solid fuel boiler

They operate from 2 to 6 hours on one load of fuel. Absolutely autonomous: do not depend on the electrical network or the availability of gas. More modern modifications have built-in electronic temperature sensors and a control panel, as well as a boost fan, which makes the operating process more comfortable.

Advantages:

• time-tested technology;
• simple and reliable to use;
• relatively low cost, wide range of manufacturers, models and prices for boilers;
• the ability to use fuel available in your region;
• autonomy - no connection to the electrical network is required;
• low level of efficiency;
• simple boiler piping;
• low cost of fuel compared to energy resources and gas tariffs.

Be prepared to need significant fuel storage space

Flaws:

• it is necessary to equip a warehouse for storing fuel reserves;
• shallow depth of temperature control;
• inertia of the fuel combustion process;
• the need for fuel delivery and preparation.

Advice. The coal burns slowly and gradually, maintaining approximately the same temperature in the firebox. Firewood and its by-products ignite faster, so they cannot immediately fill the entire firebox. This will lead to a short-term release of a large amount of heat and overheating of the boiler, which is very dangerous.

Pyrolysis solid fuel boilers

Pyrolysis boilers are a relatively new technology. This type of boiler is used for heating and water heating. They have two combustion chambers. In the first chamber, the fuel itself burns under an artificial oxygen deficiency. During combustion, volatile substances are released, which burn in the second chamber.

Construction of a pyrolysis boiler

Pyrolysis boilers operate on wood, fuel briquettes, pellets, brown coal, there are models that consume coke and coal. The fuel must be dry, otherwise water vapor entering the second chamber can extinguish the boiler. Some pyrolysis boilers are equipped with a thermostatic air regulator and devices that protect the boiler from boiling. In case of boiling, the thermostatic valve will release the water by opening the damper and the temperature inside the boiler will drop.

Advantages:

• Efficiency of at least 90%;
• minimal amount of ash and soot formation;
• Additional fuel is required 2-4 times;
• convenient and reliable to use;
• the fuel burns completely, the ash pan does not need to be cleaned often;
• reduced emissions of harmful smoke into the atmosphere;
• Large unsplit wood can be burned.

Afterburner chamber of pyrolysis boiler

Flaws:

• complex boiler design;
• high price;
• the wood must be dry (no more than 20% humidity);
• connection to the electrical network is required;
• at a load of half power, combustion is unstable, tar forms in the flues;
• There is no way to automate the fuel supply process.

Advice. The boiler can be placed in almost any technical room with an organized air flow. The chimney can be installed internally or externally.

Pellet solid fuel boilers, boilers with automatic fuel supply

In Europe, this type of boiler is very popular. They are used for heating, as well as for heating water for domestic needs. Pellets are used as fuel for these boilers - pressed shavings, sawdust from wood. The main important convenience is automation. They do an excellent job of maintaining the set temperature. All you need to do is fill the bunker with fuel at the beginning of the heating season. The boiler has a built-in auger that will independently feed pellets into the firebox. The only disappointing thing is that you can’t burn anything other than pellets.

Automatic pellet boiler

Advantages:

• durability, service life more than 20 years;
• automation of fuel refilling;
• automatic ignition;
• Efficiency 90%;
• Stably maintain the set temperature.

Flaws:

• works only on wood pellets;
• high cost of fuel and equipment;
• connection to the mains is required.

Important. Using unsuitable fuel leads to excessive fuel consumption and can cause equipment failure.

Long burning boilers

This type of boiler can operate on coke, brown and hard coal, peat briquettes, firewood, wood chips, and sawdust. Those models that are designed to work only on wood differ only in the air supply system and the materials from which the combustion chamber is made. You can load up to 50 kg of fuel at a time. The burning time of firewood is from 12 hours to two days. If the firebox is filled with coal, the burning time will be from four days to a week. If it’s warmer outside and there’s no need to heat it too much, you can reduce the boiler power by 10% simply by lowering the fuel burning rate.

Long-burning boilers are very convenient because they do not require constant fuel supply

Long-burning boilers are new generation boilers. In many models, the boiler has a bottom, which indicates complete tightness. Solid fuel burns in such a boiler from top to bottom. This is why they can run for so long on one load. The fuel does not burn all at once, but only the first 10-20 cm. The air supplied to the firebox is heated by the outgoing smoke, and then enters the combustion zone using a recuperator. The air distributor is always at the fuel combustion level.

Advantages:

• non-volatile;
• with one load, coal works for up to 5 days, and wood for up to 2 days;
• deep power regulation;
• the ash is removed 2-3 times a month;
• the price of such a boiler is lower than a pyrolysis boiler, but higher than a classic long-burning solid fuel boiler.

Installed long burning boiler

Flaws:

• Efficiency is low;
• full cycle operation without the possibility of additional fuel loading;
• Additionally, it is necessary to install a circulation pump that operates from the network.

Advice. Some manufacturers provide replaceable burners, which allows the user to easily switch from one type of fuel to another (for example, from coal to pellets) without losing the comfort of using the boiler. The user only needs to change the burner and reconfigure the automation.

How to heat a house with a solid fuel boiler: video

Solid fuel boiler for home: photo