There are different types of heating devices used in private houses, but more and more users prefer to purchase a combi boiler for heating a private house. It is an apparatus capable of operating simultaneously on several types of fuel: electricity and gas, solid fuel or diesel.
Combined boiler operating principles
Combined boilers are usually equipped with two furnaces for different fuels. The principle of operation depends on the type of product. For a device powered by electricity and solid fuel, the first option is auxiliary. It is characterized by the presence of a heating element in the heat exchanger, which works when connected to the power supply. If there is a power outage, the device is switched to firewood. In this case, additional equipment is not required.
Some types of boilers do not depend on the power grid, as they operate on gas and liquid or solid fuels. When switching over, it is not necessary to change settings or install additional burners, since they are already included in the design. Most models are equipped with a firebox and a union nut, with which you can switch between fuel lines.
Advantages and disadvantages
An electric wood boiler, as well as other options for devices, provide an uninterrupted supply of heat to a private house. The equipment allows you to use a certain type of fuel at the most convenient time in order to save money. The following advantages stand out:
- no need to install backup heating equipment;
- autonomy of work;
- versatility: any type of fuel can be both primary and secondary;
- high level of efficiency;
- profitability;
- simplicity and ease of use - most products are equipped with automation;
- service life: up to 25 years;
- the ability to connect a warm floor system.
The combined device also has disadvantages: the high cost of equipment, the need to organize a place for storing liquid or solid fuel, and expensive maintenance. The devices weigh a lot. A professional is required to complete the setup.
Fuel combination options
The combined heater operates on gas and electricity, wood and gas, wood and electricity, or three types of fuel. Each type of boiler has its own advantages and features of work.
Gas and electricity
A gas-electric apparatus is installed if the house needs to be provided with heat and hot water. In such a system, it is allowed to mount several circuits. The device is small in size and consumes little power. Electricity in this case is an auxiliary fuel option.
Since there is no separate combustion chamber in the device (the heating element is installed in the heat exchanger), the total cost of the boiler is low. However, electricity cannot be called cheap energy, therefore, in regions where gasification is poorly developed, it is better to provide for other options for heating devices.
Gas and firewood
Combined gas boilers, where a gas burner and a wood-burning stove are combined, are more economical. Devices of this type are heavy and are installed only on the floor, since steel and cast iron are used for the manufacture of furnaces. The market offers two- and one-circuit models. The first type provides the house with warmth and hot water.
Such a boiler is equipped with one common or two separate fireboxes. The second option provides for the location of the gas burner at the bottom of the structure, and the chimney at the top. Both fireboxes are heated at the same time. To eliminate combustion products, there is a special tray, which greatly facilitates the cleaning process. But it is installed only in the case of using solid fuels. The product has the following positive qualities:
- ease of maintenance and operation;
- the ability to connect 2 heating circuits;
- independence from the electrical network;
- high efficiency (up to 90%).
The gas water device needs additional foundation equipment during installation. A separate room is required for storing firewood or pellets. You also need a constant reloading of firewood.
Electricity and firewood
Combined boilers for heating a private house "wood-electricity" are the safest option. The main type of fuel in this case is wood or pellets. Electricity is only needed to maintain the room temperature at the same level. The device is convenient to use at night, as there is no need to throw firewood into the firebox every 4 hours.
The electric wood boiler is equipped with an automation system that controls its operating mode, as well as its power. It is not necessary to manually switch between fuels. The unit has a high level of safety. An electric solid fuel boiler is characterized by the following advantages: low cost of equipment, the ability to automatically adjust, high efficiency.
Multi-fuel heating boilers
The multi-fuel version of heating devices is good because it allows you to use 3 or more types of fuel: gas, electricity, pellets, firewood. It is equipped with several combustion chambers. Additionally, an electric heating element can be provided in the design, which is localized in the heat exchanger.
Since the pellet burner can be easily removed, there is the possibility of using diesel fuel or gas. To install such a unit, the following conditions must be met:
- Electricity supply without interruption. Only then can a pellet, gas or diesel burner work.
- Availability of an organized supply of selected fuel materials.
- Providing a separate room for storing materials.
Before installing combined boilers "solid fuel-electricity-gas", it is necessary to calculate the feasibility of their use. The cost of such a device is high and not available to everyone. Chimney equipment is required, as well as ensuring a minimum draft factor for each fuel material used.
Criterias of choice
To know which combined unit to choose for heating a private house, you need to take into account the technical parameters of the device, the size and number of floors of the structure, the required power.
- Power. 10 sq.m. area requires 1-1.5 kW of thermal energy. For a double-circuit boiler, this figure increases to 1.5-2 kW for the same area. If this value is exceeded, the device will run idle. This accelerates component wear, increases fuel consumption and increases the cost of heating in general. Operating in this mode promotes the formation of condensation inside the machine.
- Fuel availability. Not all regions have the opportunity to connect to the gas main or buy firewood.
- House size.
- The need to organize the supply of hot water. If there is already a boiler in the house, there is no need for a double-circuit boiler.
- Unit cost. It depends on the power, additional functions, reputation of the manufacturer.
- Dimensions and material of manufacture of the device. The dimensions of the boiler are important if it will be located in a small room. Of the materials, steel or cast iron is considered the best option. Such products are characterized by a long service life.
- Availability and availability of components.
- Weight. For some devices it is necessary to build an additional foundation.
- Installation requirements. Most gas or electric heaters require special permission from the relevant services for installation.
- Ease of use. It is good if the device is equipped with automation and additional security levels.
You can install the product in the kitchen, but it is better to allocate a separate room for it. You also need to pay attention to the complexity of setting up and connecting the device.
Installation of combined boilers
Multi-fuel devices are mounted according to a pre-developed project, as well as after obtaining permission from special services. The installation has the following requirements:
- Premises. The unit may only be installed on a concrete base, which must be reinforced. The walls of the room must be constructed of non-combustible materials. It is important to keep dry in the boiler room. The room must be well ventilated. The minimum distance from the boiler to the walls is 30 cm. The boiler room must comply with fire safety standards: a sheet of metal is laid in front of the firebox; it is forbidden to store flammable substances in the room.
- Chimney. The inner diameter of the structure is equal to the pipe of the heating device. To ensure a normal draft level, the chimney must rise above the roof ridge. It must not be damaged. To avoid the formation of condensation inside the chimney, it must be insulated. The structure requires periodic cleaning.
- Electricity grid. It must be able to withstand the boiler load. If the power of the heating element is more than 6 kW, the optimal voltage in the network is 380 V. Electrical equipment should not come into contact with water in any way. The temperature in the boiler room should remain within the range from 0 to +45 degrees.
The stove in the house has long been an outdated structure, instead of which multi-fuel boilers are successfully used. They require correct installation and adherence to operating rules, but they provide uninterrupted heating in any conditions.
