Universal heating: boiler for wood, gas and electricity

Gas-firewood

The advantage of universal gas-wood heating boilers is their autonomy: a smooth transition of the system to burning wood in the event of a lack of gas. Also, if desired, you can connect a “warm floor” structure, because the necessary connections and pipes are included with the boilers.

Such universal gas-wood boilers can be single-circuit or double-circuit, so connecting a boiler to heat water or heating water using a flow-through method is not difficult.

The disadvantages include the large dimensions of such units. Most often, they require a separate room for installation, and involve complicated maintenance. Typically, such boilers are produced only of the floor-standing type.

Combined gas-wood boilers for the home imply increased requirements. Norms and rules of operation are described in PPB, SNiP and SP.

A gas-wood combination boiler for a private home includes the following elements:

1. Fire chamber. It is made of cast iron or steel. The boiler can have one firebox or two (more convenient). In the double version, wood is burned in the upper section, and a gas burner is installed in the lower section.
2. Hot water supply and heating circuits. They are produced by companies specifically for heating, or for heating the production of hot water (double-circuit). Heating of hot water using a flow-through method.

A universal gas-wood heating boiler implies savings. You can verify this by looking at the following table.

High-quality equipment using wood and gas is produced in Russia: “Zota MIX”, “Kupper PRO” (“Teplodar”), “Karakan” (“STEN”), “PARTNЁR” (“KOSTYOR”), “STS” (“Steel Solid Fuel Systems"). As well as foreign companies: Austria and Germany (“Wirbel”), the Finnish concern “Jaspi” and others.

It should be noted that in foreign analogues it is less common to notice shortcomings in the assembly and automation of the unit. They boast reliability and quality. However, the domestic manufacturer is constantly improving in accordance with the wishes of customers.

Prices for combined wood-gas heating boilers depend on the country of origin and the popularity of the brand. For example, the model (“BONTER”) will cost an average of 23 thousand rubles. Much will depend on the configuration, power and other indicators. But “Jaspi” will cost 130 thousand rubles. The run-up is large, however, unlike the Finnish one, where everything is regulated automatically, in the Russian analogue you will have to carry out all the boiler settings yourself.

Reviews of universal solid fuel and gas boilers: advantages and disadvantages

Coal-gas

The universal gas-coal boiler is environmentally friendly and easy to maintain. However, when choosing this type of design, you will have to constantly monitor the availability of solid fuel, because coal runs out quickly. If you suddenly come to the conclusion that “two in one” is not suitable for you, then you can always replace the burner - and the boiler will already operate on natural gas.

You can read more about the features of a pellet boiler here.

Most often, a combined coal-gas boiler can also be heated with wood. For example, in the technical characteristics of the dual-circuit model “Beryozka V”, in the “fuel” item it is indicated “natural gas / coal” (see table). However, buyers use such a boiler for heating with wood.

Gas-coal-wood

The advantage of a gas-wood-coal boiler is that it does not depend on electricity. This allows you to create autonomous heating systems. Fuel for such a unit is available in any locality and, moreover, at a low price. The wood-coal-gas boiler from the manufacturers listed in the table below is easy to service and has an attractive design.

Solid fuel boilers: operating features

The prices for solid fuel boilers can hardly be called low, but in the case of a house located remote from a populated area, there is often no other choice. Naturally, solid fuel boilers are practically not used in the city or in holiday villages, since there are a lot of other, cheaper ways to provide a home with heat. However, it is sometimes simply impossible to gasify a private house, which is why solid fuel boilers become the only heating option. It is also worth buying a solid fuel boiler because it has a fairly high efficiency at a relatively low cost of fuel.

For a long time, solid fuel boilers were not very popular due to the impossibility of automating their operation process. Today, this problem has been completely solved, and models capable of operating in autonomous mode for a long time have entered the market. The use of such long-burning solid fuel boilers makes it possible to provide the house with the necessary amount of heat without spending time on constant reloading of fuel. It is enough to load fuel once, and the boiler will operate efficiently throughout the day.

Firewood-coal-pellets-gas

Currently, these units are offered by: the manufacturer of the universal boiler “Cooper” “gas-wood-coal-pellets”, and others.

A large selection (pellets, firewood, coal, gas) gives such a boiler a great advantage. In the absence of one type of fuel, you can always switch to another type and stay warm.

Gas pellets

A pellet gas boiler is equipment that easily changes its operation from heating with one type of fuel to heating with another. This usually happens in about 15 minutes.

Here it is also possible to replace the burner in case of conversion. Many models have a tubular electric heater.

It is allowed to connect a liquefied gas cylinder.

The efficiency of a pellet gas boiler reaches 90%.

The unit has several combustion chambers. The kit includes two burners, as well as many control and shut-off devices. Has a high degree of security and automation. But despite this, a gas-pellet boiler, like any combined gas boiler, requires compliance with the standards of PPB, SNiP (some excerpts are described at the beginning of the article).

Don't forget to clean the boiler from time to time. During the maintenance process, it is necessary to remove accumulated wood dust and soot from the electric drive and moving elements.

What do you need to work with pellets?

To convert the boiler to fuel pellets, you need to install a pellet burner, which is connected to the fuel hopper. After all operations, the boiler operates as follows:

• granules are supplied to the burner via a conveyor from the fuel bunker;
• electric ignition occurs immediately via a piezoelectric element;
• a built-in fan is activated in the burner, which increases the pressure, and the pellets burn at a high temperature, raised artificially.

Typically, gas-pellet boilers are made of cast iron, and due to their large dimensions and weight, the structure is placed on a concrete base.

What do you need to work on gas?

Pellet boilers with a gas burner are connected, first of all, to cylinders and gas holders. Such units are gaining popularity in the construction of houses and sites where natural gas is planned to be installed soon.

To connect a gas burner, you first need to close the unused firebox with an airtight hatch. Then you need to install a burner device in a place specially designated for gas equipment. After everything, set the switch to gas consumption. All. The modification took no more than 15 minutes.

Combination boiler Wirbel ECO-CK 20

Boiler "Kupper PRO-22" with pellet burner

Boiler "Kupper PRO-22" with a pellet burner
Instead of a gas burner (as in the previous version), a pellet burner is installed, on top of the boiler there is a bunker with automatic control for a standardized supply of fuel pellets from the bunker.

When it is not possible to connect to a gas pipe, a boiler of this type will be the optimal solution in terms of automation of the heating system. And of course, as you already understand, when civilization reaches you and it becomes possible to connect to the natural gas pipeline, there is no need to change the entire boiler - only the burners.

Speaking about heating boilers, we cannot, of course, ignore electric boilers; in some cases they are also in great demand.

Firewood-pellets-gas

If you are interested in the design of this type of heating, the table below describes the manufacturer of gas, solid fuel and pellet boilers, its most popular model and a brief description.

Thus, combined boilers for heating a home are an excellent option for obtaining not only heat, but also saving money. Since there is always a choice of fuel and its autonomous switching, in the absence of one specific type of fuel, your home will be heated at any time of the year. Combined boilers for solid fuel and gas are reliability, high performance and versatility.

Single combustion boilers

Combined boilers "wood/coal - gas"

Today, there is no main gas supply to the village where the house is being built, but it is possible to use firewood to fire the boiler - a universal single-fuel boiler is selected, when instead of the loading chamber door, a gas burner can be installed in it in the future. In this case, there is no need to buy an additional gas boiler. You can choose an atmospheric burner, in which gas is mixed with air to create a combustible mixture naturally, or a pressurized one, equipped with a fan, with its help the gas burns in the chamber much more efficiently, its consumption is reduced. The disadvantages of a pressurized gas burner are its energy dependence, noise and higher cost.

According to the degree of regulation, forced-air burners are divided into:

— single-stage, when when the required coolant temperature is reached, the burner is turned off and then turned on again;

- two-stage, when in the first stage the boiler operates at 100% power, and in the second at 50-60%, and this significantly saves fuel;

- modulated, with smooth adjustment of the gas combustion flame, which allows the boiler to operate in the range from 10 to 100% of power, and gas consumption is saved by 15% or more compared to unregulated burners, if the operating mode of the modulated burner is configured correctly.

The situation may look different: gas is supplied to the house, but the gas pressure in the network is unstable, or has disappeared altogether, and there is a need in the middle of winter to urgently switch to an alternative type of fuel in order not to defrost the system. Removing the gas burner and installing the combustion chamber door of a universal boiler is not a difficult task; any man can handle it by tightening a few bolts. It is assumed that there is enough space on the territory for storing firewood in a ventilated place, protected from precipitation, or in a specially folded woodpile.

In houses where people do not live permanently in winter, it is sometimes economical to use liquefied gas as fuel in their dachas. For significant volumes of its storage, the installation of a tank is required, and this entails obtaining permission from the gas service, compliance with the protected zone, and other requirements, and it will be filled by special refueling vehicles. You can use gas in cylinders; they can be combined into blocks of up to 10 pieces. and one cylinder with a volume of 40 liters is enough to heat a house with an area of ​​up to 50 m for about three days. Liquefied gas is more expensive than main gas, but for its use there are less approval costs and if the house is used infrequently, on weekends and the system is filled with antifreeze, this heating option can be used in the boiler. Cylinders cannot be installed in the same room as the boiler; a reducer is required to convert the liquid state of the fuel into a gaseous state with a volume of 1.8-2 m³/h and a gas train (proportional gas supply valve). The burner used is the same as for main gas.

Combined gas/diesel fuel boilers

One of the most common types of universal boilers is the combination of “gas/diesel” in the fuel used, since both substances burn in a firebox of approximately the same design and the transition by changing the burner is carried out quickly and with simple settings. In the line, for example, of German Buderus boilers there are models both in steel (the marking contains the letter “S”, they are for large objects, the power line starts from 71 kW) and in cast iron (“G”, power 25-1200 kW, these boilers are more often used in individual houses). Such models are very popular in Europe, in addition to natural and liquefied gas and diesel fuel, they can also run on biofuel - rapeseed oil, they use technologies that reduce harmful emissions of exhaust fumes into the atmosphere and various techniques to reduce fuel consumption. These cast iron boilers are low temperature. Thus, the cast iron boiler Buderus Logano G215 WS (power 40-95 kW) is manufactured according to the Thermostream principle, thanks to which it can operate stably without the use of a mixing pump or return temperature controller.

Combined boilers “wood/coal-electricity-gas-liquid fuel”

There are quite inexpensive models, such as those of the Russian brand Zota, which can operate on many types of fuel: in normal mode using wood/coal, with the additional installation of a heating element - on electricity, and when installing the corresponding burner, also supplied as an option - on diesel or gas.

Using such a boiler as an example, we can consider options for switching from one fuel to another in a combined unit.

It should be understood that one mode will be the main mode for the boiler; it is according to this mode that the boiler power will be calculated, and other fuel sources will become backup. For example, when operating on solid fuel, the boiler produces full power, and if the firewood runs out, the device will automatically switch to heating with a heating element (if there is a special control module), but will work with a decrease in the initial power. This mode is intended to protect the house from defrosting in the event of an emergency shutdown of wood burning, but not for full heating to a comfortable temperature. Nevertheless, this is the most common way to complete a universal boiler; for small heated areas, you will not feel any difference in temperature comfort and it will allow you to significantly save on the purchase of an additional electric boiler and installation of pipes.

Installing a liquid fuel burner will reduce the efficiency of the boiler, since heating with wood and diesel fuel has different heating principles: when burning with wood/coal, the heat rises from the bottom up when the coolant is heated, and from the burner the heat spreads horizontally in the boiler, strongly heats the back wall of the boiler, which, with prolonged exposure it may burn out. Additional thermal insulation of the rear wall will be required. Diesel and fuel oil burners are described in detail in the article on liquid fuel boilers; in this case, we are only talking about the possibility of a simple transition of a universal device to this type of fuel if necessary. Diesel fuel is stored in plastic containers either indoors, with a protective metal tray in case of leakage, or, if the composition of the soil allows it, buried next to the boiler room; a place must be provided in advance.

Sometimes, it is convenient for owners of car service centers located in areas remote from the main gas supply to use universal boilers with a firebox for wood/coal and a special burner for working with waste oil. According to reviews, its efficiency is not bad, but the oil consumption required varies depending on the power and you must constantly have a supply of it, which is only possible with a large turnover of material.

Changing a diesel burner to a gas burner or installing a gas burner on a boiler that was previously fired with wood is also not difficult if all the equipment is from the same manufacturer. If the transition from gas to another type of fuel does not raise any questions, then the reverse transition sometimes requires attention: when burning with diesel, for example, a significant amount of soot is formed in the chimney, and when the gas burner is turned on, soot from the walls of the chimney can crumble and block the chimney. A good burner should turn off in this case, but if this does not happen, the resulting carbon monoxide can enter the room, which is unfavorable and sometimes dangerous. Therefore, when switching from a diesel firebox to gas, it is better to invite a service specialist who will clean the chimney and start the boiler.

All of the above conditions for switching from one fuel to another are typical for single-fuel boilers, that is, when all types of fuel burn in one chamber and heat one coolant circuit. This type of universal boiler is the most economical and if you do not intend to frequently switch from one type of fuel to another, you can consider it. Universal boilers can be made of cast iron or steel. The former are more bulky and heavy, but given the difference in heating mode when changing fuel, cast iron may be preferable. Nevertheless, there are steel boilers with a bent, seamless body, which in the low power range can also successfully act as universal boilers.