Combined boilers are often used to heat private homes or country cottages for heating a house - they will ensure a comfortable temperature in all rooms, regardless of the presence or absence of a centralized gas supply or firewood.
A significant plus of such units is the adjustment of the cost estimate not only for heating the building, but also for the supply of hot water. In addition, it is very convenient to be able to use different types of fuel, agree?
The effectiveness of combined boilers in the absence of access to the central supply system of energy resources is confirmed by numerous reviews of their owners. The main task is to choose the optimal type of heating unit.
We will help you make the right choice. The article describes the features of operation, operation and maintenance of different types of combined boilers. We identified the main criteria for evaluating equipment and gave practical recommendations for choosing a heating unit.
The main types of combined boilers
Combined heating equipment is focused on loading and processing of two or more types of fuel materials.
More than 70% of the models on the market are equipped with special electric heaters that contribute to the partial or complete refusal to use the main heating elements for heating water in the summer season.
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Autonomous heating equipment
Specific design
Procurement of a machine
Stable performance boilers
Units for work on gas and electricity
Combined gas firewood models
The use of liquid and solid fuels
Modular burner change principle
The type of fuel material used allows you to conditionally divide the equipment into 2 main groups:
- standard - apply no more than two different types of fuel;
- universal - able to work on three or more fuel options.
In most cases, it is possible to replace the burner in order to change the fuel supply function. Also available are models equipped with hobs and even two burners with electronic or electromechanical control.
The catch here is one - the more extended the functionality of such an aggregate, the more complicated the process of its installation will be.
Pellet boiler refers to solid fuel plants. It burns pellet pellets made from wood waste (+)
Owners of country houses in which heating is provided by a combined heating boiler unanimously declares its indisputable advantage. Especially if the house is located far from large settlements, and the lack of gas supply and frequent power outages are the norm in this area.
In addition, the combined boiler, which is also called universal, has many other advantages.
They allow you to compete with the most popular types of single-component systems:
- the ability to connect multiple circuits;
- a wide range of resources for technical modernization - burner replacement, boiler installation;
- modern level of program management;
- no interruptions in the heating system - at the time of the cessation of the supply of one of the types of fuel, it is possible to use an alternative option;
- economical consumption of funds for providing a heating system.
Models with electromechanical control will be simply indispensable in homes located in areas that are often faced with power outages.
This option allows, if necessary, to transfer the boiler unit to the manual adjustment mode, without losing its productivity.
The performance of the boiler becomes the main one when choosing a boiler from the presented wide model range
Popular fuel combination options
Various variations of combined heating units make it possible to solve various problems - from large-scale to less global problems. For example, they are able to provide hot water supply for a single family of 3-5 people, as well as heating an office building or an apartment building.
Option # 1 - gas / electricity combination
Electricity is the most effective for heating water. A rapid increase in temperature is due to exposure to the coolant, with the least share of delay.
The main priority quality of equipment with a combination of gas / electricity is its variability, which is manifested in the possibility of connecting to several heating systems, as well as the option of installing several circuits
Characteristics of combined heating appliances that provide significant advantages:
- Small sizes. The device has an oversized combustion chamber for burning gases, a heat exchanger with a built-in heating element or other type of heating device;
- Low power consumption. The boiler operates on gas, and the electric heater is put into operation only on demand - for quick heating of water or in the absence of access to the gas supply;
- Low price category. This is achieved due to the absence of a separate combustion chamber - the heater is installed inside the heat exchanger. In equipment where there is no secondary circuit, the option of connecting a water heater is planned;
- TENY with a small power - many models on the market are designed only to support the specified temperature.
Although gas is an economical type of fuel, this cannot be said about electricity. Therefore, for houses located in an area with a poorly developed gas supply network, you should look for another version of the boiler that runs on different fuel.
Option # 2 - a combination of firewood / gas
More economical types of fuel are gas and firewood. The dimensions of the heating apparatus operating on such fuel are impressive - it has separate combustion chambers for each type of fuel.
Design features of boilers with a combination of gas / firewood type determine the placement of one or two heat exchangers. For the first case, it serves as a common element for all combustion chambers.
In case of interruptions in gas supply, the equipment will switch to electricity - for a month of such heating there will be a round in the payment for electricity
In a double-circuit boiler, only one type of fuel is used to ensure hot water supply. This type of combined boilers requires you to pre-issue permits for installation.
In addition, these boilers are divided into two subspecies: with a common and separate combustion chamber. The first option relates to installations created independently. They are used to minimize the final budget for the heating system of a country house.
With your own hands, a gas burner is installed in the classic boiler model, if solid fuel is used, it is dismantled. This option creates unacceptable working conditions for the heat exchanger - exposure to high temperature during burner operation. It is this that is a frequent cause of boiler malfunction.
When issuing a permit to install a boiler of a gas / wood type combination, the main aspects are the technical indicators of the solid fuel zone, which should not affect the gas
The design with separate chambers of the furnace is equipped with a dual-circuit system, one of which is used to heat water during heating, and the other to provide hot water.
In the event of a solid fuel boiler conversion for the use of diesel fuel, only blast burners are installed:
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Solid fuel boiler to be reworked
Blast gas burner control unit
Connecting the burner to the combustion chamber
Blow burner control unit
Boiler automation sensors
Installing the control unit on the wall
Liquid fuel storage tank
The transfer of solid fuel heating equipment to the liquid version will reduce costs without losing productivity. This solution is advisable if it is not yet possible to switch to the use of main gas. Still, diesel heating is 2-3 more expensive than gas.
Option # 3 - a combination of firewood / electricity
If it is impossible to connect to the main gas supply or the arrangement of heating with cylinders, solid fuel boilers are most often used. They have great power and are non-volatile.
Structurally, combined boilers such as firewood / electricity are quite similar to gas models. Self-production of this type of device is also available. It will be enough to determine the required power, select the heater and mount it in the heat exchanger.
Factory models of universal boilers for heating wood / electricity are equipped with a full set of necessary elements. The power and placement of the heating elements are correctly designed in them, which leads to a high level of safety during the operational period
In addition to these characteristics, it is necessary to note the following features of combined heating boilers running on wood and electricity:
- supporting opportunities - connection of the heating element block through the contact zone with the temperature controller or a special software unit that provides remote control of the boiler;
- increased breakage resistance - factory ones provide heat supply due to the operation of heating elements (heating elements) that can withstand high thermal effects during operation of the furnace compartment;
- maintainability - in case of failure of the electrical part of the boiler, it can easily be replaced. In many models of gas heat generating plants, such a function is not available.
The capacity of a solid fuel boiler is relatively slowly regulated. In connection with this feature, manufacturers recommend using the electronic part of the heating system to quickly adjust the heating level.
Option # 4 - multi-fuel plants
Design features of multi-fuel heating equipment for domestic use are based on the use of several alternative fuels. Such heating systems include models with the combination of pellet pellets / gas / firewood / electricity.
In most variations of pellet boilers of a combined type of heating, the burner is presented as a removable element, so its combustion chamber can be used for other types of fuel
The most significant structural feature of pellet combined heating boilers is the equipping with several combustion chambers, adapted to use one of the types of fuel - solid or liquid.
In addition to the functionality, it is possible to install an electric heating element located in the heat exchanger chamber.
Due to the easily removable pellet burner, it becomes possible to use other types of fuel, for example, diesel or gas.
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In boilers designed for the use of all types of fuel, a volumetric firebox is arranged, in which firewood, coal, pellets are loaded. It is possible to install one, two or more heating elements
In the assortment of combined boilers there are models with a removable hopper that can be removed and put back if necessary in its operation
In the design of combined boilers that consume fuel in any aggregate state, there is a combustion chamber for gas and diesel
Particularly noteworthy are the combined boilers operating in the solid fuel version according to the pyrolysis principle. They are economical, suitable for installation in almost any infrastructure conditions
Equipment for universal use
Boilers with removable pellet hopper
Additional camera in construction
Universal pyrolysis boiler
For the use of this kind of energy, the necessary conditions for creating a forced draft pressure and certain structural features of the heat exchanger. All these characteristics are characteristic of pellet boilers.
A multi-fuel heating system can be installed only after the following requirements are met:
- Uninterrupted power supply - a necessary condition for enhancing the operation of a pellet heating boiler, gas and diesel burners (the use of solid fuel materials is an exception);
- Organized supply of fuel materials to the boiler - this is the most acute problem when designing the installation of heating boilers with a combination of gas / firewood / electricity;
- Providing storage space for energy - for the use of balloon heating, external steel boxes are mounted or a separate room is allocated, and in some cases a building; diesel is stored in tanks connected to the pump unit.
Before purchasing universal heating equipment, it is necessary to analyze the main factors affecting the choice of a specific model.
So, the feasibility of using each type of energy carrier should be assessed, because the cost of such a device is much higher than single-fuel systems.
The necessary diameter of the chimney must be calculated in advance, as traction coefficient must meet at least the minimum requirements for each fuel material
How to choose the right boiler?
The only objective criterion for choosing a combined boiler for your home is the necessary power to ensure the functioning of the heating system. Moreover, the number of connected circuits should not affect this indicator.
It makes no sense to pay more for a powerful boiler in the hope of adjusting its operation by automation. This approach contributes to the "idle" operation of the device, which leads to a faster failure. In addition, this mode of operation accelerates the condensation process.
As for the calculation of power, theoretically, for heating an area of 10 m2, 1 kW of heat energy will be required.
But this is a rather conditional indicator, which is adjusted based on such parameters:
- ceiling heights in the house;
- number of floors;
- degree of insulation of the building.
Therefore, it is advisable to use one and a half coefficient in their calculations, i.e. in the calculations, increase the supply by 0.5 kW. The power of a multi-circuit heating system is calculated with a premium of 25-30%.
So, to heat a building with an area of 100 m2, a power of 10-15 kW is required for single-circuit heating of the coolant and 15-20 kW for a double-circuit.
To select a gas burner in a solid fuel boiler, you need to accurately measure the dimensions of the combustion chamber. It is to these proportions that the size of the gas burner will correspond
An equally important criterion when choosing a combined heating boiler is the price category. The price of the device depends on the power, number of functions and manufacturer.
For users, other characteristics are equally important:
- DHW
- material of manufacture;
- convenience in management;
- dimensions;
- components;
- weight and installation features;
- other things.
The issue of domestic hot water needs to be resolved immediately: the boiler will supply hot water or there is an electric boiler for this.
In the case of determining the first option, a more preferable method is chosen - accumulative or flowing, as well as the parameters of the water tank according to needs (calculated based on the number of residents).
As for the dimensions of the equipment, they only matter if they are installed in a room with a small area.
According to the material of manufacture, a wide range of boilers is presented. But the most popular options are steel or cast iron. Also, such a boiler is able to withstand high and long temperature load, has a higher operational life.
Judging by the intensity of sales and relying on consumer reviews, the following models are actively in demand:
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The equipment runs on all types of fuel, including electricity. The double-circuit unit perfectly copes with heating a house with an area of up to 200 m² and with the supply of hot water for a family of 4-5 people
Zhytomyr-9 boilers are represented by single and double circuit models. They work on solid fuel with an efficiency of 78%, on gas with an efficiency of 92
Designed for use on solid, liquid fuel and natural gas. Perfectly heats a house with an area of up to 200 m². Equipped with automation. Productivity varies depending on fuel within 90-95%
The dual-circuit combined boiler processes all types of fuel. In the basic configuration there is a blast burner, an electronic control unit and its own circulation pump. Excellent house heating up to 350 m²
The owners of the boiler can choose any type of fuel, including natural gas and electricity. Rated power 22 kW, when connected to the mains only 6 kW. Heats 220 m²
The solid fuel unit is designed for the use of coal or firewood. Reserve fuel is diesel, gas and electricity. Serves up to 500 m², performance when connected to the mains is 6-9kW
The fail-safe model fully complies with the specifications declared by the Korean manufacturer. Suitable for arranging a one-story private house, up to 220 m²
The combined boiler from the company Teplodar of the Cooper PRO 42 brand is designed to heat an area of up to 420 m². There is an opportunity to install heating elements. On wood, it works according to the long-burning scheme, one bookmark of firewood is enough for 8 hours
Popular Zotamix 20kw unit
Czech unit ATMOS DC18SP
Performance Kiturami KRM 30R
Affordable Kupper PRO 22
Powerful ZOTA MIX 50 unit
Stable Working Kiturami KRM 20R
Automation of control affects usability, and the security system depends on how automated the process of energy combustion. Most models can be controlled using convenient remote controls or panels.
Most models are equipped with additional equipment. This may include the presence of a cooking surface for cooking, injectors, traction controllers, burners, noise insulation casing, etc.
Choosing a boiler for this parameter should be based on personal preferences and the amount allocated for the purchase.
When choosing a heating boiler with a combination of firewood / electricity, it is necessary to calculate the required power of the heating element. It is recommended to choose models with an indicator of at least 60% of the required coefficient for heating a house
But on the weight of the equipment and the complexity of its installation, you must immediately pay attention.
Installation in a residential building of most floor models of combined boilers for heating, equipped with several combustion chambers, requires an additional concrete pedestal, because the standard floor covering will not be able to withstand such a load. The best solution is to equip a separate boiler room.
Knowing the main parameters that affect the choice of a combined boiler, you can choose the most suitable model.
Additional selection recommendations, as well as a comparative overview of different heating units for a private house, are given in this article.
An example of a pellet combined heating boiler:
Regardless of the type of equipment chosen, it is necessary to design a future heat supply system before purchasing it. These include: pipelines, chimney and safety measures during operation of the heater.
This will ensure the full functioning of the heating system with minimal energy costs.
Looking for an efficient combination boiler for your home? Or is there experience in using such installations? Please leave comments on the article, participate in discussions and share your impressions about the use of heating units.