It is customary to call a boiler a furnace designed to operate as the main unit of a water heating system and equipped with a heat exchanger for a liquid coolant. Solid fuel boilers are an excellent solution for a country house in an area where there is no gasification. Universal, economical and fireproof heating systems built on the basis of a solid fuel boiler will provide the house with heat, hot water and create comfort. And all this at a reasonable price.
Types of heating boilers by energy source
In addition to the obvious advantages of living in the country, the owner of a country house has a lot of responsibility - including for the heat in the house. For heating and hot water systems, the following types of systems are used:
- Electric.
- On liquid fuel.
- Gas.
- On solid fuel.
Each of the classes has its own advantages and disadvantages. The solution for heating a private house with a solid fuel boiler is the most versatile in terms of fuel used, high autonomy and the lowest cost per kilowatt of heat. In addition, atmospheric systems with natural coolant circulation are not affected by interruptions in the power supply network. If in your area there is no centralized gas supply, it makes sense to consider solid fuel heating boilers.
Types of solid fuel
The most widely used solid fuel for heating boilers , such as:
- Firewood.
- Coal.
- Peat.
- Briquettes (eurowood).
- Pellets
Each type of fuel has its own disadvantages and advantages, and many of them are determined by the geographical and economic characteristics of a particular region. When choosing a device, you must definitely think about what kind of fuel it will be heated and evaluate the economic efficiency of a particular choice.
Manufacturers produce solid fuel heating boilers, both optimized for a specific type of fuel, and universal.
Firewood
This is the oldest type of fuel mastered by mankind. Traces of primitive bonfires are found in parking lots dating to several tens of thousands of years ago.
Today, birch and aspen firewood are most widely used. Less commonly - alder, oak and firewood of coniferous trees. Birch firewood is a leader in calorific value, but contains a lot of tar. Burning, it turns into soot clogging the chimney. Aspen gives less heat, but the chimney has to be cleaned much less frequently. Oak firewood gives a lot of heat and burns for a long time, but is too expensive for constant use. Alder wood gives a pleasant smell, so they are often burned in open fireplaces. Firewood of conifers is not bad in calorific value, but it contains a lot of tar, and the resulting soot clogs the chimney even faster than when burning birch firewood.
The advantage of firewood is its accessibility and a small amount of dust and dirt when used. The disadvantage is that firewood can become damp, which can significantly reduce their fuel efficiency or even make the furnace impossible.
Coal
Coal is widely used for heating. They are heated both with coal and brown.
Coal has a high carbon content, it has a high calorific value and gives little ash and slag. Brown coal is of less quality, contains many impurities, gives less heat and more forms gases, ashes and slags. Its only advantage is relative cheapness.
Coal does not dampen and has a high calorific value, one and a half to two times higher than that of firewood. The disadvantage of coal is dust and dirt when used.
Peat
Peat is extracted in swamps, dried and pressed into briquettes.
It has an average calorific value, burns with the release of a large amount of smoke. It is used in regions where there are few forests, but there are swamps.
Briquettes
These are compacted sawdust the size of a small brick, processed in drying chambers. They are distinguished by high heat dissipation and the ability to long uniform burning.
Pellets
They look like small compressed pellets from sawdust, their size is optimized for mechanical feeding from the hopper.
Solid fuel boilers
Systems for solid fuel water heating have been used by man since ancient times. The boiler itself was copper, the pipes of the warm floor were ceramic, the combustion chamber was simply the space under the boiler. The physicochemical basis of the operation of the device was a simple process of burning wood or peat. Over the past millennia, the design of the boiler has become much more complicated, new materials and physicochemical processes have begun to be used, the number of inventions and patents is in the hundreds.
A modern heating boiler for a solid fuel home is a high-tech unit with a coefficient of efficiency reaching up to 80%.
Solid fuel systems are divided into:
- Wood and coal. The calorific value of coal is about one and a half times higher than that of wood of mass varieties. The combustion temperature of coal is also significantly higher. The designs of wood and coal boilers differ insignificantly, mainly they come down to differences in fuel loading systems and ash and slag removal systems.
- Universal. Most devices belong to this class. Moreover, many models have the option of installing a separately purchased gas or liquid fuel burner.
- Peat (briquette).
- Pellet. The pellet boiler is equipped with a hopper for storing fuel and a mechanical system for feeding pellets into the combustion chamber. It is controlled by an automation system that maintains the specified parameters of the temperature of the coolant or indoor temperature.Such a boiler is distinguished by the greatest autonomy among all types of solid fuel devices and can operate without owner intervention from a week to a month - everything is determined only by the size of the hopper and heat consumption. The pellet system requires a larger area for its installation, the mechanical fuel supply system needs periodic maintenance and adjustment.
Traditional oven
A traditional stove (Russian, Dutch, etc.) works as follows: solid fuel is burned in the combustion chamber, placed on the grate. At this time, full access to air through the grate located below was blown and the exhaust flap (view) is open. More or less opening the blower, you can adjust the thrust and combustion rate of the fuel. As fuel burns out, hot combustion products, including carbon monoxide, which is hazardous to health, are released from it. Passing through a winding chimney left among the brickwork, these gases heat the brick. After the evolution of gaseous products has ended (the blue flames over the coals have disappeared), it is blown and the exhaust flap is closed so that the heat from the cooling coals and masonry does not escape into the atmosphere. However, most of the heat generated from the combustion of the fuel goes to the atmosphere.
Long burning boilers
Sellers often call a boiler of long burning anyone who can maintain a smoldering regime. In the strict sense of the definition, a solid fuel heating boiler with long burning should work on one fuel load for at least 24 hours.
The long burning mode is realized due to the slow burning of fuel in conditions of oxygen deficiency. At the same time, the chemical pyrolysis process begins, which consists in the release of combustible gases from solid fuel and their subsequent combustion. The gases released during pyrolysis have a significantly higher calorific value than wood or coal, and in a traditional furnace they are simply emitted into the atmosphere.
Types of long-burning boilers
Solid fuel boilers for continuous burning are manufactured according to several schemes.
- Non-volatile or atmospheric. The movement of air in them is due to natural traction. They have slightly lower thermal efficiency, but they do not depend on the stability of power supply.
- Supercharged. In this type of boiler, air is supplied by a fan, an automatic system controls the air flow. This design allows you to achieve maximum heat transfer, but depends on the power supply.
In addition, boilers are single-circuit and double-circuit. Single-circuit boilers are designed only for heating, dual-circuit boilers, along with heating, carry out hot water supply.
Solid fuel boiler selection
The market offers a wide variety of solid fuel boilers for heating a private house. To choose a boiler, it is necessary to clearly formulate the requirements for the future apparatus.
Key parameters that affect the choice of the boiler are:
- Thermal power.
- Autonomy.
- Type of fuel.
- The number of circuits.
- Type of boost.
- Price.
The main characteristic of the boiler is its thermal power, it determines the area of the building that this model can heat.
So, for a house with an area of 60 m 2, 9 kW of thermal power is quite enough, and for a two-story cottage with a total area of 200 m 2, it is better to choose 25 or 30 kW, depending on the climatic zone, average annual and minimum temperature. The quality of thermal insulation also affects the power of the boiler. If, for example, a boiler is bought for heating an old house built without the use of heat-saving technologies, the boiler capacity will have to be increased.
Autonomy means the time elapsed from loading to loading fuel at medium power. The maximum autonomy (up to one month) is provided by pellet boilers with automatic feeding, the minimum - atmospheric devices that run on wood (up to 12 hours)
The next parameter is the type of fuel. You should choose a boiler that runs on fuel that is affordable and affordable in the region. If you have not decided on the fuel, choose a universal boiler.
Number of heating circuits. A double-circuit boiler is more expensive and more difficult to connect. If the consumption of hot water is planned to be small, then it is easier to install an electric water heater. In addition, in the summer, when there is no need for heating, you will not have to heat the boiler.
The price of boilers for water heating on solid fuel starts from 20 thousand rubles. For this money you can buy the simplest single-circuit atmospheric boiler with manual power control. A long-burning boiler with automation will cost about 35-40 thousand rubles. From 120 thousand rubles. there is a pellet boiler for heating with solid fuel. The price of a fully automated boiler with a hopper designed for a monthly supply of pellets will be close to 300 thousand rubles. For a comparable amount, an entry-level autonomous gas supply system can be supplied.
DIY boiler
Do-it-yourself solid fuel boilers can be made from a gas cylinder that has served its purpose and scraps of steel pipes and fittings. Of course, if you possess welding and locksmith skills at a sufficient level. In terms of energy efficiency, it is unlikely to even be able to get closer to industrial designs, but it will cost you the price of electrodes.
It will be required:
- Gas cylinder, 50 liters.
- Steel angle 30 * 30, 1 running meter.
- Armature with a diameter of 8-12 mm, 2 linear meters.
- Steel pipe 2 inches, scraps from 40 cm - 6 pcs.
- Bulgarian.
- Welding machine.
The cylinder is placed vertically and legs are welded to it from the corner for support. In the lower part, a door is cut out for the blower and the ash tray, immediately above it several parallel pieces of reinforcement are welded across the container - this will be the grate. In the middle part, a door is cut out for loading fuel. In the upper part of the cylinder part, 8 holes with a diameter of 50 mm are cut so that 4 parallel pipe cuts are inserted into them and the gaps are welded. Of the 2 remaining pipe pieces, 2 collectors are made connecting the protruding ends of the pipes. One end is welded, on the other a thread is cut for connection to a water heating system. Carved doors are hung on the case with the help of purchased or self-made hinges. Sometimes, cast iron cast-iron doors of industrial production are used to improve the appearance.
Compared to industrial designs, the efficiency will be low, and the appearance will be more than modest. However, such solid fuel heating boilers will function properly and will be completely suitable for heating the gatehouse or greenhouse.