Heating systems differ in range, operating modes and types of basic elements:
- heat source;
- heat generating device;
- coolant (environment that transmits the generated energy).
The solid propellant heating heatgenerator heats the liquid heat carrier used for heating and hot water supply. This heating unit heats private houses and spacious cottages, outbuildings and small public buildings.
Advantages of solid fuel boilers
Solid fuel heating heat generators have a large number of positive qualities:
- deprive heating of dependence on centralized energy sources (gas), tariffs for them, pressure in the main pipe, the state of the distribution network;
- do not require thorough water treatment (as electric — to preserve heat transfer from the surface of the heating elements);
- do not force to create a fuel supply system (as for gas — from the main), install containers for several tons, for diesel fuel, fuel oil, an electric pump for their continuous supply;
- explosion-proofnot easily flammable (unlike gas, diesel);
- lower operating coststhan electric, liquid fuel units, a kilowatt-hour of produced thermal energy is cheaper;
- from liquid fuel more environmentally friendly;
- many models not dependent on electricity;
- do not react to air pollution (unlike gas and liquid fuel), successfully heat unfinished premises;
- solid organic fuel ash — fertilizer.
Types of solid fuel boilers for the home
The fuel used is the main criterion for dividing heating boilers into types. Electricity is used by electric units, natural gas — gas, fuel oil, diesel fuel — liquid fuel. Solid fuel units “feed” on wood, peat and products from them, coal (stone, brown), coke.
The principle of operation of the system is simple.
Fuel is fed into the combustion chamber, ignites. If there is a gas generator, then it turns into combustible gases — it is gasified.
A torch of burning gas is sent to the tank, heats the water, which circulates in the system by gravity or under pressure (due to the pump). Boilers with a gas generator are called pyrolysis. Less ash remains in them, soot is almost not formed. The efficiency of pyrolysis ovens is higher than traditional ones, but they are more expensive.
To maintain the pyrolysis regime, the moisture content of firewood should be kept within the permissible limits.
The heat from the water is transferred into the room through radiators, convectors, pipe registers.
Disadvantages of solid fuel heat generators:
- require a special room for installation;
- air ducts are needed for air supply, chimneys for the removal of combustion products;
- a sufficiently spacious room is required for fuel supply;
- not free delivery, unloading;
- an almost continuous presence of a person is necessary (to control the combustion process, fuel supply, ignition, if these processes are not automated).
Automation of the operation of the heating unit — equipping it with a bunker for the operational reserve of fuel, screw feeders, a special volumetric type burner with a built-in photosensor.
The inclusion of a pump, thermostat, electronic sensors, safety valves in the system makes the heating mode constant for several days. From the control panel temperature, a daily cycle of work, inclusion, shutdown are set.
In order to automate the maintenance of the furnace as much as possible, it is necessary to operate fuel units with a constant shape and size. These qualities are possessed by granular raw materials.
Wood, peat granules (pellets) are economical, environmentally friendly. In terms of energy efficiency, a pellet boiler is comparable to a gas boiler (efficiency 85–93%).
Raw materials (chips, sawdust, shavings) are crushed to a powder fraction, dried, granulated. The final moisture content of the granules is 8–12%, the density is 5–10 times higher than that of the feedstock. The standard “grain” shape is a cylinder, d = 6–10 mm, l = 5–70 mm.
A pellet stove requires human participation when the supply of pellets in the operational bunker runs out — once every 5–7 days. There are models with a volumetric fuel bunker. Autonomous mode of their work on one gas station reaches 30 days. Ashes are removed monthly.
On a note. Woodworking waste is the most common material for fuel pellets (pellets). However, not only crushed sawdust, chips and shavings, but also waste from oil extraction and agricultural production are suitable for the role of raw materials for alternative fuels. Sunflower husks (crushed to 2–4 mm), straw are not inferior to recycled wood in quality, have a lower ash content (almost 2.5 times), and are cheaper.
Pellets are more convenient to store than firewood, their calorific value is almost 1.5 times higher (in this indicator they are comparable to coal). The life of the boiler on pellets reaches 20 years.
Disadvantages of pellet heat generators:
- humid microclimate during storage and transportation is fraught with a decrease in the energy value of the fuel;
- design features of pellet aggregates affect their cost.
When deciding which solid fuel boiler to choose, the quality and area of u200bu200bthe house are taken into account. When choosing the power of the unit, with low heat losses and ceilings not higher than 2.7 m, they approximately consider: 1 kW per 10 m2. The optimal area of a house heated by a pellet heat generator is 120–170 sq. m.
In the furnace of traditional boilers, firewood and coal are loaded every 3–6 hours. New generation units (with firebox extended upwards, special air supply) burn fuel slowly (7 days of work on one tab).
They also say about pyrolysis units: “long burning”, noting the increased time of their work on one load. Then, before choosing a long-burning solid fuel boiler, you should take care of a spacious firewood shed for drying logs.
The main features and characteristics of solid fuel boilers Viadrus (Czech Republic)
The range of Viardus solid fuel boilers is represented by 13 types:
- seven of them require manual loading of fuel;
- at six, fuel is supplied automatically.
It is permissible to heat all devices with manual loading with firewood, and in the Lignator and Hefaistos P1 models, only pieces of wood can be burned.
The maximum thermal power of the Lignator is the lowest of the non-automatic units — 34 kWh (with wood moisture less than 20%), but the efficiency is high — almost 90%.
On a note. Developers of solid fuel boilers take 15 (less often 12) kW as the minimum power. It is more economically feasible to generate a smaller amount of thermal energy (heat a small space) with a fireplace. (A fireplace equipped with a water circuit can be connected to a heating radiator, the efficiency of such a system is 85%).
Hefaistos P1 is much more powerful — it produces 30–100 kW of heat per hour (depending on the number of sections) at operating pressure up to 400 kPa, fuel consumption 8–27 kg/h, combustion efficiency 83–89%. The diameter of the logs is 8–15 cm, the length is determined by the depth of the firebox.
Unlike Lignator, Hefaistos P1 is pyrolysis.
The “manual” models of the Hercules series are less “choosy in nutrition”: they prefer firewood, but “assimilate” other solid fuels:
- model U28 can be fired with lignite (the stove will give 17–46 kWh);
- the same type of fossil, coke is suitable for the operation of Hercules U24 (13–74 kWh);
- in models U22, U26 they burn coke, hard coal (which releases more heat during combustion than brown).
A feature of Hercules U22 (which has a thermal power of 12–58 kWh) is the ability to burn logs of high humidity — up to 25%. Hercules U26 is distinguished by high maximum power — 72 kWh.
Among solid fuel boilers from Viadrus with manual loading the VSP IV model stands apart.
The heat generator has a number of features:
- sections of the unit are arranged in 2 rows;
- work as part of a centralized low-pressure heating network is permissible (it is possible to connect several circuits);
- potential versatility (it is possible to rebuild the unit for burning gas, peat, diesel fuel);
- the ability to increase the safety of the heat generator (installation of a blast burner);
- the VSP IV does not burn hard coal.
The power of the VSP IV heating boiler is an order of magnitude higher than other models with manual fuel loading — 146–386 kWh.
On a note. Power above 500 kW reduces the efficiency of the boiler and its life: the structures will burn through in 3–5 years. And yet, there are pellet heat generators more powerful than 2 MW (and much more expensive than conventional ones). Their design is complicated by a special device for the pre-treatment of wood pellets in the combustion process.
For the automatic loading of solid fuel into the combustion chamber, you will have to “pay” with a relatively small thermal power of the boiler. Power of Viadrus boilers with automatic loading of solid fuel (kW∙h):
- Woodpell — 5.8–25 (performed by 5- and 7‑section, efficiency 91%);
- Hercules Duo, Fanda — 6–35;
- Hercules Green Eco Therm — 7.5–32;
- Hercules Eco — 7–42.
Of the five listed Viadrus products, only one works not only on pellets: Hercules Duo is also heated with brown coal.
The VSB Eco model stands apart. It is as productive as the VSP IV, ready to go to manual operation, able to run on lignite, coke, natural gas, biogas, liquid fuels. The unit can heat a store, a public building.
On a note. A solid fuel boiler for agricultural engineering is being developed. The purpose of research and testing is to create a heat-generating device that works efficiently on a specific fuel — bedding manure (more precisely, on its solid combustible component). The new technology utilizes the by-product of poultry farms and provides them with thermal energy.
Which solid fuel boiler to choose, models and prices
Any model of solid fuel boiler Viadrus finds its buyer. Smaller heat generators are preferred by owners of small but warm cottages. More heat requires heating the cottage. Then the choice depends on the possibility of combining heat generators of several types, installing a heat-insulated water accumulator.
Hercules Duo popular due to the fuel of two types in the “diet”. The price is about 200 thousand rubles. Hercules U26 is suitable for conversion to automatic Hercules Duo, which also affects demand.
The modification kit includes a burner, pellet feeders, a bunker, panels with automation and sensors, the inner metal of the furnace and other parts.
It is possible to re-equip for automatic pellet Hercules U22 with 5–7 sections. His price: 60–700 $ — if 5 sections, 60–70 — if 7.
(The cost of a 2‑section model U22 C2 is 45–500 $.9‑section — 80–100).
Not ignored by buyers and pellet Woodpell (160–180 thousand rubles).
More than 500 thousand rubles. it will cost to buy a seven-section Viadrus Hefaistos P1 — the so-called solid fuel boiler for long burning on wood.
Readers’ reviews about long-burning wood-burning boilers
After the vacation, we were able to decide which solid fuel boiler to choose: we saw Hefaistos P1 T7 (seven-section) in the holiday home. For the dacha, they chose the same, but smaller (the depth is only 1.5 meters, sections — 5). 40 kg of firewood is enough for 3 hours of work, if the work is at full capacity.
Veronica Z., Podporozhye, Ladeynopolsky district.
Why not all furnaces can be loaded with fuel briquettes? Briquetted raw materials have a higher density and lower moisture content. The combustion process proceeds differently and gives different results, which not every furnace is designed for.
A 5‑section Legnator was enough for heating a small cottage with low heat loss. It weighs less than 400 kg, compact — the depth is not more than a meter. We heat the water to 70 degrees (comfortable, especially with low ceilings).
Vyacheslav D., Oryol
I chose Hercules U22D 5 for a 155 m round house2. Cast iron is suitable for both firewood and coal. I drown in the evening, by the middle of the night it burns out. It is already cold to get up in the morning — I will combine it with an electric boiler.
Installation and adjustment
Before installation, read the basic rules:
- Heating boilers are not allowed to be installed in a residential building, including utility rooms. A room with a continuous flow of air is allocated under the boiler room (the intensity depends on the characteristics of the boiler).
- The basis for a heavy unit, with a flame and hot water inside, is a plinth made of non-combustible material. The contour of this stable fire protection is left protruding beyond the boundaries of the boiler by 2 cm in all directions.
- Any surfaces in the boiler room should not be closer than 20 cm from the boiler casing. Concrete, brick, ceramics, fiberglass and, moreover, wood and rubber are no exception.
- Materials that ignite easily and are capable of self-sustaining combustion cannot be located closer than half a meter from the boiler. These are cardboard, polyurethane, wood fiber materials, PVC, etc.
More information about the combustibility of materials — in the instructions for the product. In any case, when determining the installation location of the boiler, it is necessary to retreat at least half a meter from the walls of the boiler room.
The minimum height of the boiler room is also standardized (for example, for Woodpell it is 2.1 m).
- Leave at least a meter of free space in front of the heating boiler.
The installation of a solid fuel boiler for heating a private house and the adjustment of its work are carried out by qualified specialists authorized by a certified company. The existing heating system is pre-washed and cleaned.
The quality of the water in the circuit — hardness, the content of iron, manganese, calcium — are normalized. If necessary, the coolant is softened and cleaned. After installation, the system is checked for tightness, the first heating is carried out.
Heating boilers designed for heating residential premises heat a liquid heat carrier — water, water-based antifreeze. (This way of transferring the generated energy reduces the danger of the system: the steam is hotter). Viadrus boilers are not designed to heat antifreeze.
Maintenance of the heating boiler requires strict adherence to the manufacturer’s instructions.
- Do not leave fuel near the boiler: the minimum distance is 1000 cm.
- The best place for fuel waiting to be loaded is another room.
Viadrus boilers, designed for solid fuels, are cast iron. Cast iron products are more reliable, more durable than steel ones, as a heat exchanger they are more inertial (heating up longer, cooling down longer).
- The role of thermal insulation of boilers is played by non-asbestos mineral material.
- The shell of the boiler is varnished, its removable parts are attached to the bolted connections.
The heating boiler is the most common heat generator in the home heating system. Autonomy combined with modern developments and European workmanship expands the use of units for coal, wood, briquettes and pellets.