Condensing boiler. What is a condensing boiler and how does it work? How does a condensing boiler work?

Today condensation gas boilers are the most popular models of equipment for heating systems due to their positive operational features, which distinguish them from other types of heating equipment.

Device and purpose

The main purpose of condensing heating devices is the arrangement of a heating system in private homes.

Among the main elements of condensation gas boiler heating should be noted:

A device that is designed to collect condensing liquid, into which the coolant flows after cooling the exhaust air masses. Thus, the steam condenses and releases thermal energy water. The condensate is then discharged into a special container through a drain device.
Heat exchanger cylindrical with a large heat transfer surface. This device is made of acid-resistant materials: stainless steel and aluminum-silicon alloys. Boilers with high power have a pair of heat exchangers.

Gas-burner with a closed combustion chamber. It is possible to automatically change the flow rate of supplied gas and air masses.
Monitoring and management system.

To study in more detail the operating principle of condensing boilers, you need to have some understanding of conventional boilers. Traditional boilers produce thermal energy by heating the coolant using heat accumulated in combustion products. The temperature of the gases entering the combustion chamber is no more than 200 degrees. This is justified by the fact that with a decrease in temperature, the draft decreases, active condensate is formed, leading to corrosive destruction of the heating equipment.

As was said, condensation heating devices have one two-stage or two separate heat exchangers. The initial stage works on the same principle as in the heat exchangers of classic heating units. Decomposition gases enter a heat exchange unit called a condenser.

IN in this case the vapor present in the decomposition gases is cooled and condensed until the liquid phase occurs. The heat released during the process is transferred to the coolant. Thus, in condensing apparatuses, a certain part of the expended energy is returned so that it can be reused.

The heat, which is usually released into the atmosphere by classical units, is used in the condensing apparatus to increase their coefficient useful action. Condensing gas boilers are available in two versions: floor-mounted and wall-mounted units, but their design features are similar to each other.

In condensation-type devices, condensate is usually directed into a special container provided by the design of the equipment, and then into the sewer system.

Since condensation-type heating units are equipped with closed combustion chambers, exhaust gases are forced out of them. This is explained by the fact that the exhaust gases have a relatively low temperature, and an additional heat exchange unit will increase the resistance to transporting the exhaust products. As a result, natural traction is not enough to remove products, which is why the forced method is used.

Air is supplied to the combustion chamber under high blood pressure using a turbine, which ensures complete removal of exhaust gases from the chamber. As a result, there is no need to equip boilers with chimneys, since the products are removed from the room through the supply and exhaust channel. Condensing boilers can be installed in rooms without chimneys, as well as in buildings with short chimneys, in order to generate a certain draft.

Condensing equipment is considered more fireproof, since combustion is carried out in complete isolation from the building where the device itself is located.

Advantages and disadvantages

Positive characteristics of condensing equipment:

There is no need for a chimney, which has complex design. Since the temperature of combustion products is low, it is possible to install a chimney made of aluminum and plastic pipes. The installation of coaxial chimneys is also permitted, where the air mass is supplied and discharged using the “small pipe in big pipe", that is, combustion products are removed through the wall into the atmosphere.
Compactness combined with high performance. The line of condensing units with a capacity of 120 kW are made in wall-mounted variations. Traditional gas devices They take up much more space and are only available on the floor.

Fence air mass for optimal functioning from the building in which they are located. Thus, there is no need to install special boiler rooms for equipment with a power of less than 60 kW.
Reducing the release of harmful gases and vapors into the atmosphere.
Significant gas savings. At quality installation 60 kW devices can save about 2000 m3 of fuel over the winter.

Negative characteristics of condensing type equipment:

Expensive. On average, the price of standard boilers of the same power is up to 40% lower than the cost of convection boilers.
Condensate cannot be drained into a septic tank, so a special tank is needed to collect condensate, where it is neutralized using neutralizing components, and only then can it be sent to a drainage tank. The condensate tank must be of sufficiently large capacity, since equipment even with low power produces a high volume of condensate.
The need for a heating system operating at low temperatures.
Ineffective work when too low temperatures, since there is a need to increase the temperature of the coolant.
Energy dependence.

Based on reviews from owners of private houses who have installed gas-fired condensing boilers, taking into account all the pros and cons, we can make right choice apparatus for the heating system.

Features of operation

Condensing type equipment uses natural or liquefied gas as fuel. The first is widely used in everyday life, and the second in industry. The operation of the condensation device is based on the laws of physics. The fuel burns, releasing water and carbon dioxide. In this case, the liquid evaporates and a certain amount of heat is released. The formation of condensation ensures that lost thermal energy is returned to the system, which leads to an increase in the efficiency of the system. In standard boilers, condensation is considered an undesirable phenomenon that needs to be gotten rid of.

The main difference between condensing boilers and convection boilers is that the latest models are considered obsolete. Also, the efficiency of condensing equipment differs from conventional and convection equipment by up to 15%.

Most buyers note that the cost of purchasing condensing-type equipment is compensated by the high efficiency of the device, which is ensured by the condensation of vapors contained in flue gases. After cooling flue gases in the heat exchanger up to 55 degrees, condensation of water vapor begins with the release of additional heat, due to which the efficiency increases.

Condensation is possible only if the coolant temperature is no more than 57 degrees and the greatest effect is achieved at 35 degrees coolant in the return.

Installation of condensing type equipment is relevant in heating systems with low temperatures.

Criterias of choice

Regarding the technical characteristics of boilers, you need to pay attention to the following points:

Performance. Too much high power maybe not always good option, and functioning at half capacity will soon lead to equipment failure. Therefore, before purchasing a device, it is necessary to calculate the optimal power for heating the house. To do this, you need to calculate the area of the building, height and level of insulation. You can even use special tools for research of a private house. With their help, existing heat losses. Optimal power condensing devices depends on the climate zone. For example, for Moscow, for a 10 m2 house, the equipment power should be in the range of 1-1.5 kW. Thus, for a private heating system with an area of 200 m2, you need equipment with a power of at least 20 kW.

Number of circuits. Dual-circuit devices on liquefied gas They work as follows: the first heat exchanger heats the coolant for the heating system, and the second heats the hot water supply. A single-circuit turbocharged boiler heats only the thermal agent. For many buyers, the second option is not entirely convenient, but when organizing a hot water supply system, you can simply install an additional boiler. With intensive use hot water can be purchased and double-circuit boilers with a boiler. Thus, opinions converge on which condensing type equipment is better.

Double-circuit devices most often have low power - up to 24 W, and are installed in rooms with good level insulation or with system autonomous heating. In other cases, options with one circuit are most optimal.

Gas consumption rate depends on the boiler performance, efficiency, and heating system load. – The material from which the heat exchanger is made.

The speed of heating response to external factors largely depends on it:

Silumin, or an alloy of silicon and aluminum, is designed to combat aggressive condensation. In this case, the heat exchanger must be seamless, since the presence of seams increases the risk of corrosion.
"Stainless steel" is considered inexpensive material compared to silumin. To the benefits of stainless steel include resistance to corrosion, lack of inertia and immunity to thermal shock. Therefore, the rating of materials for the manufacture of heat exchangers is headed by “stainless steel”.

Environmental friendliness. Conventional turbocharged boilers, when burning fuel, emit vapors with acidic impurities into the atmosphere, and in condensing devices the vapors dissolve in condensate and are neutralized.
The operating temperature affects the efficiency of the equipment. As the temperature decreases, the intensity of condensation increases. Thus, at a vapor temperature of 30 to 40 degrees, the rate of condensation formation is highest. In this case, condensation occurs in a constant mode.

Control. Modern condensing devices are equipped automated system management. Automation allows you to control and manage temperature conditions, flow rate and pressure in the circuits. The most advanced boiler models are regulated through a special application on a smartphone.
Installation method: on the floor or on the wall. Floor-standing models with one circuit are available with a power of more than 100 kW and are easily connected to boiler equipment using pumping units. If hot water is used intensively, the floor-standing boiler will become great solution. If the house area is small and much less water is consumed, it is recommended to give preference wall models with two circuits. They are compact and have low power - up to 100 kW, are easy to install and do not require a special chimney.
Pricing policy for condensing type gas boilers.

For most modern people who, one way or another, are faced with choosing a heating boiler, a unit such as a condensing boiler is associated with reliability, durability and efficiency. This is a relatively new development, which people have not yet fully understood - yes, many advantages are attributed to it, but whether this is really so, time will tell. We will not overtake it, but will simply look at what it is and how it works. Together with the site, we will understand the operating principle according to which a condensing gas heating boiler operates, we will become familiar with its advantages and disadvantages, as well as many other things characteristic of this combustion unit.

Gas double-circuit condensing boiler photo

Condensing gas boiler: what is it?

If we compare a standard gas boiler with its condensing analogue, we can come to the conclusion that their differences lie not only in some innovations, but in radically different operating principles. Yes, in both cases the heating of the coolant occurs due to the combustion of gas, but in a condensing boiler the heating of the coolant is additionally carried out using exhaust gases.

Moreover, the smoke removal system in this case produces primary heating of the liquid - exhaust gases, in which large quantities contains water vapor, the coolant is first heated, and only then the gas directly heats it to the set temperature. It is thanks to all this that fuel savings occur - the efficiency of condensing boilers is 15-20% higher compared to standard units of this type.

How does such a boiler work? If you do not delve into its design in detail, you can describe the sequence of the technological cycle of heating the coolant as follows.

Everything is simple, but in fact, this approach to heating the coolant requires some re-equipment of the boiler. Firstly, the coolant is supplied to the heating system in such units at the bottom of the boiler. Secondly, the upper low-temperature condensing heat exchanger is equipped with a tank for collecting condensate. Thirdly, all these innovations significantly increase the dimensions of the boiler. In principle, it’s easy to put up with all this if such equipment really allows you to save gas, which is the main advantage of a boiler of this type. But besides him, this one gas equipment there are other advantages.

Pros and cons of condensing gas boilers

As you already understand, the main advantage that gas condensing boilers have is high coefficient beneficial action - without increasing fuel costs, they produce more power than classic gas equipment of this type. In addition, the following points can also be attributed to the positive aspects of the operation of these boilers.

All this is very good, but along with the advantages, gas condensing boilers also have disadvantages. Firstly, maximum efficiency and economy in operation is achieved only under low-temperature operating conditions - if the temperature of the coolant in the return pipeline exceeds 50 degrees, then the boiler will operate as standard gas equipment. This imposes some restrictions on the scope of its application - to ensure the efficiency and economy of the condensing boiler, a large area is required. Alternatively, they can be used in systems with a large amount of underfloor heating. Secondly, the cost is more than 2 times higher than the price of a conventional gas boiler. Thirdly, the complex and difficult adjustment of the heating system, which is very difficult to carry out without specialists. And fourthly, there is the need to drain condensate - a branch needs to be installed to boiler equipment of this type.

And this is not all the unpleasant aspects of using gas condensing boilers - when paired with conventional linear boilers, they do not work quite as expected. Maximum efficiency this equipment is only possible with collector circuits heating system wiring.

Types of condensing gas boilers

Like most other gas boilers, condensing equipment of this type can be classified according to several criteria.

Like all other boilers, condensing units differ in power, which you should pay attention to first of all, since the ability of the boiler to heat a room of a given area fully depends on this indicator. The maximum power of wall-mounted condensing boilers cannot exceed 24 kW - in contrast, the same figure for floor-standing equipment of this type can reach up to 100 kW.

Manufacturers of condensing boilers

It's no secret that the quality of any product depends on the manufacturer - condensing boilers are no exception. They cost a lot of money and when purchasing such units, you need to be sure that the money is not wasted, and they will be able to work for a long time. long term. In this regard, it is better to give preference in choosing to trusted manufacturers, which include the following companies.

If we talk about economy class condensing equipment, here we can highlight BAXI boilers, which have optimal combination technical characteristics and cost - a 28 kW boiler will cost the consumer approximately $1,500. At the same time, the manufacturer gives a rather considerable guarantee on its products, which makes this boiler very affordable for a wide range of people.

To conclude the topic about a condensing gas boiler, I’ll say a few words about one very important point, influencing the duration of operation of equipment of this type. We are talking about a heat exchanger, or rather the material from which it is made - almost all condensing boilers are equipped with heat exchangers made of stainless steel or silicon-aluminum alloys. In principle, both options work well, but stainless steel is less susceptible to corrosion due to condensation. Both will work for a long time, but it is stainless steel that lasts the longest.

For many, the term “condensing boiler” is synonymous with reliable and economical heating equipment. However, not everyone can explain what this concept means and how a condensing-type unit differs from a conventional gas boiler.

Operating principle and internal structure

In traditional gas heating units, flue gases, the temperature of which is +100-(+170 0 C), together with the resulting water vapor, are removed into the atmosphere. The calorific value of the fuel used in such installations is called the lower calorific value. Condensing gas boilers, thanks to their use in their design and production latest technologies, are capable of converting the energy of condensation of water vapor into heat.

Definition! The total energy of combustion of gaseous fuel, including the energy of transformation of water vapor into liquid, is called the gross calorific value of the fuel.

Features of heat exchangers of condensing devices

Almost every gas boiler can theoretically be made condensing by retrofitting it with a condenser/heat exchanger and ensuring that additional aerodynamic resistance to the removal of combustion products is overcome.

Attention! The surface temperature of the condensing heat exchanger must be below the dew point of the fuel used.

At the beginning of the development of condensation technologies, the production of units of this type followed exactly this path. Operating heat generator installations, as a rule, were floor-mounted units made of cast iron, and were equipped with plate condensation modules made of corrosion-resistant steel.

Relatively recently, unified heating systems began to be created gas installations, originally designed for operation in condensation mode. Heat exchangers of such units must:

ensure intensive and efficient removal of steam condensation energy;
be resistant to condensate, which provokes corrosion processes.

Definition! Condensate from gas boilers is a mixture of low concentration coal, nitric, and sulfuric acids.

A gas condensing boiler is manufactured with one or two heat exchangers:

In the first case, it is a double heat exchanger with a branched heat exchange surface, made of stainless steel.
In the second case, the high-temperature heat exchanger is made of aluminum-silicon alloys, copper, and stainless steel. Typically, such a heat exchanger is made of stainless steel.

Attention! In wall-mounted boilers for high-temperature heat exchangers, cast iron is not used due to its significant mass.

Advantages of condensing heating gas equipment

The innovative design of the burners ensures almost complete combustion of fuel; due to the high efficiency, the amount of gas used is reduced (by 10-15%) and, consequently, the amount of emissions into the atmosphere is reduced.

Attention! Maximum efficiency is obtained when using units of this type in low-temperature heating, for example, in underfloor heating systems.

Equipment, thanks design features, is almost silent.
Wall-mounted models can have a power of up to 100 kW, while traditional wall-mounted gas boilers produce a maximum power of 35 kW.
The service life of this heating equipment is 2-3 times longer than that of conventional gas units.

Manufacturers of heating equipment of the type in question

High-end condensing heating equipment includes products from the German companies Viessmann and Buderus, and the Italian company Baxi.

Condensate gas Viessmann boilers Vitodens have a power range from 4 to 66 kW. These units are manufactured using a fundamentally new heating surface design. The Inox-Radial heat exchanger is a parallelepiped twisted into a coil. Stainless steel is used for its production. The company completely abandoned the installation of aluminum heat exchangers due to lower corrosion resistance and, therefore, shorter service life.

Attention! The design of Inox-Radial heat exchangers provides the possibility of installing, if necessary, devices for neutralizing condensate.

The Vitodens 300, 333, 343 are equipped with fuel-saving modulating burners and modulating circulation pumps, reducing energy consumption to a minimum. 26 kW units cost approximately $1,800.

The German company Buderus is a pioneer in the field of condensation technology. Logamax plus GB 112 models are manufactured with a power of 80 and 100 kW, which is a record for wall-mounted gas boilers. At the same time, the units have compact dimensions - their width is equal to that of conventional boilers with a capacity of 24 kW. This equipment uses a finned heat exchanger made of silicon-aluminum alloys. approximate price boilers of this brand with a capacity of 24 kW - $1,400.

BAXI brand models represent a combination of excellent performance characteristics and reasonable prices. The 28kW Prime HT model costs approximately $1,500. This economy-class condensing wall-mounted boiler is equipped with the ability to electronically modulate the flame, both in heating mode and in hot water preparation mode.

Progress in the production of gas heating equipment has stepped far forward - it is enough to study the functionality of the models on sale to see this from your own experience. But equipment is evaluated not only by its functions, but also by other parameters - cost-effectiveness and efficiency. And the most advanced in terms of these characteristics is a condensing gas boiler, which allows the maximum conversion of gas combustion energy into heat supplied to heating.

In this review we will look at:

Design features of gas condensing boilers;
How condensing equipment works;
What are the pros and cons of these boilers?

In conclusion, we will go through the most popular models among buyers and study their main technical characteristics and functionality.

Construction of condensing boilers

An ordinary gas boiler has an extremely simple design. Here is located gas unit with valve connected to the burner. Hanging over all this is a single heat exchanger, responsible for heating the coolant to a given temperature. A mechanical or electronic control system is responsible for maintaining the temperature. Equipment efficiency reaches 90-92%, depending on the design of the selected device and the type of combustion chamber - models with closed chambers burn fuel more efficiently.

If single-circuit gas boilers are designed simply, then their double-circuit “colleagues” are a little more complicated - here a secondary heat exchanger is added (or one bithermic one is installed) and three-way valve. All these nodes are responsible for preparing hot water. The equipment has good efficiency and eliminates the need to purchase an additional water heater.

Condensing boilers are even more complex, because they are characterized by increased efficiency and a high efficiency rate - it reaches 98%. The technology of moisture condensation from the released combustion products is used here. Since they are still full of heat, they can be taken away and put into the heating system. This achieves significant fuel savings - depending on the model and operating conditions, it amounts to up to 10%.

Gas condensing boilers include the following components:

At the moment, condensing boilers are the most modern and efficient solutions in the field of heating systems.

Combustion chamber - open or closed. This is where the incoming fuel is burned. Moreover, the vast majority of condensing units are built on the basis of closed chambers, while models with open chambers are rare;
Main heat exchanger - here the main selection of thermal energy takes place, which is carried away by the hot coolant;
Condensing heat exchanger is the most important detail gas condensing boiler. This is where moisture condenses and heat is released into the heating system;
Secondary (or bithermal) heat exchanger and three-way valve - these components are responsible for the operation of the DHW circuit;
Control electronics – responsible for the operation of all equipment installed on board;
Drainage – responsible for draining condensate into the sewer system.

A condensing boiler is more complex than any other convection unit. But this is precisely what allows it to extract maximum thermal energy from combustion products.

The complexity of condensing boilers directly affected their cost - they are at least 30% more expensive than their convection counterparts.

Operating principle of condensing boilers

Let's look at the operating principle of a condensing gas boiler and find out how it receives additional energy. We have already said that the principle of moisture condensation from combustion products is used here. If we take hold of the chimney pipe, we will find that it is warm, and in some cases even hot (it all depends on the efficiency of the equipment). It is this thermal energy that we can select into the heating system.

The condensing boiler works as follows:

It is the presence of a second heat exchanger, in which hot steam condenses and releases the remaining energy, that determines such a high efficiency of the entire system.

The gas burner releases thermal energy, which is absorbed by the main heat exchanger;
Combustion products enter a large area condensing heat exchanger;
The cold coolant passing through the condensation exchanger causes the formation of condensation, taking thermal energy from the water vapor;
After this, the coolant enters the main heat exchanger.

For some, it may remain unclear where water vapor comes from in the first place. There is nothing strange here - it is formed as a result of the combustion of natural gas. If we look closely at chemical formula reaction taking place here, we will see in its results two main components - water vapor and carbon dioxide. It is steam that contains the thermal energy we need.

The condensing boiler is characterized by increased efficiency. This becomes possible due to more complete extraction of heat from combustion products. Manufacturers claim that the efficiency is up to 115%, but you cannot go against the laws of physics - you cannot get more energy than it was expended. And such a high efficiency is just a marketing ploy aimed at increasing sales. In reality, the efficiency reaches 98%.

When creating a condensing boiler, the developers did everything possible to make the equipment economical and energy efficient. But the efficiency directly depends on the temperature of the coolant in the return pipe. The lower it is, the better; the optimal indicator is from +30 to +40 degrees. If the temperature is high, there will be no condensation - the heat will escape into the atmosphere, and the efficiency will drop. Therefore, the coolant first enters the condensation, and only then into the main heat exchanger.

In other words, in order to save on gas fuel Due to the high efficiency, it is necessary to create a heating system with a relatively low coolant temperature - the optimal ratio will be +30 degrees on the return pipe and +50 on the supply pipe.

Advantages and disadvantages of condensing boilers

A condensing boiler is a unique piece of equipment created by heating engineering developers. It cares about the environment and allows you to save on gas fuel. Condensing boilers are widely used in European countries, where people care about their well-being and about nature. And there they are the leaders in consumer demand.

In Russia, a condensing boiler is a rarity - consumers are not ready to change their equipment headlong to cleaner, from an environmental point of view, equipment. And it's all about her high cost, because some models cost up to twice as much. But those who can count and are comfortable with mathematics know that the initial costs are justified by savings on fuel. You just need to configure the equipment correctly so that it operates at the optimal temperature.

Let's look at the pros and cons of a condensing boiler - let's start with the positive qualities:

If it seems to you that a 10 percent saving is not so great, then just calculate how much money you will spend on gas at least over the next 5-7 years. We assure you that the numbers will unpleasantly surprise you.

Saving on gas fuel – here we can expect real savings, reaching 10% and even a little more. That is, if we work hard to reduce heat losses in our home and install a condensing boiler, the savings on gas fuel will be up to 20-25%. For example, the gas consumption of a 20 kW boiler is less than 2 cubic meters. m/hour, while for similar convection models it is approximately 2.2 cubic meters. m/hour;
Reduced load on environment– the more efficiently fuel is processed, the better for nature. It’s bad that not every person understands this;
Low temperature of combustion products - since thermal energy is removed almost completely, the temperature of the gases at the outlet of the gas boiler is extremely low;
Possibility of unhindered use with water floors - they just need a low coolant temperature. In traditional high temperature heating, gas condensing boilers will be a waste of money;
Wide selection of models - any power (up to 50 kW and more), single-circuit and double-circuit, floor and wall-mounted, with open (rare) and closed by cameras combustion.

There are also disadvantages:

Low coolant temperature will require a recalculation of the number of sections in the radiators - there is no escape from this. But you can do it differently by installing small baseboard convectors or heated floors instead of traditional radiators;
High cost of gas condensing boilers - if you take a similar convection model, then with equal power, characteristics and capabilities it will cost less (on average, condensing models are 30-80% more expensive);
The need for condensate removal - its excess is removed into the sewer system;
Decrease in efficiency as the temperature rises - if you suddenly want to turn on the gas to make the rooms warmer, the efficiency will begin to drop quickly;
Energy dependence - all gas condensing boilers require electricity. Therefore, consumers will have to take care of the reserve;

According to statistics, to create autonomous heating in their homes, most Russians purchase gas heating systems, which are rightfully considered the most economical and environmentally friendly.

Modern industry offers huge selection boiler equipment, differing in many parameters, among which the most common are thermal power, functionality, method of installation and exhaust gas removal. This publication will cover hot water gas boilers, which have some design differences from traditional heating installations. We are talking about condensing and parapet type boiler equipment.

Energy from steam condensation

To understand what a gas condensing boiler is, you must first consider the operating principle of a traditional boiler system. When gas is burned, heat is released, which heats the heat exchanger and, accordingly, the coolant passing through it. After which, the heated coolant enters the radiators, where heat exchange occurs between the air and the coolant, and combustion products are discharged through the chimney.

From a school chemistry course, everyone knows that combustion is an oxidation process that occurs with a large release of thermal energy. When a gas-air mixture burns, carbon dioxide and water are released, which is in a vapor state. In order to turn water into steam, a colossal amount of energy is expended.

The operating principle of a condensing gas boiler is to convert water vapor found in fuel combustion products back into water. During condensation, steam releases the accumulated heat to the surface of the heat exchanger.

It works like this: the return flow from the heating system enters the condensation heat exchange chamber of the boiler, through which the exhaust gases pass. The temperature of the coolant coming from the system is much lower than the temperature of water vapor from combustion products. The steam condenses on the walls of the heat exchanger, releasing the accumulated thermal energy to the coolant, which, being warm, enters the primary heat exchanger, where it is heated to the nominal temperature.

The heated coolant flows back into the heating system, and the condensate is discharged through the drainage into the sewer system. The acidity of condensate usually does not exceed 3.5 units: discharging it into the sewer does not violate established standards.

For boiler units of this type, the efficiency reaches up to 98%, with lower fuel consumption (compared to traditional installations with the same technical parameters).

The efficiency of the boiler depends on the temperature of the inlet boiler equipment coolant: the lower it is, the Device efficiency higher. The operation of this device becomes most efficient at temperatures of forward and reverse coolant flow of 40/30°C.

Parapet installations

Due to the huge range of heating equipment presented on Russian market climate control technology, many of our compatriots are interested in the question: “What are parapet gas boilers?”

Despite this somewhat tricky name, these are completely energy-independent boiler units, with a sealed combustion chamber, which represent a kind of symbiosis of a gas boiler with a convector. The scope of application of this technology is wide: from production premises, to heating city apartments and private houses that do not have a stationary chimney. The removal of combustion products and the supply of air necessary for normal combustion of gas is carried out through a coaxial chimney.

Because this type heat generators are non-volatile, it will only be used in heating systems with natural circulation coolant.

Structure of a parapet boiler unit:

Housing made of thick-walled steel. It has an easily removable decorative casing with an inspection door. Thanks to perforation, this heating device, not connected to the heating system, performs the function of a convector.
Burner block with gas valve. The unit consists of a main and pilot burner and is mounted on an easily removable frame structure. The pilot burner includes a thermocouple and a spark electrode.
Sealed combustion chamber.
Heat exchanger with copper coil.
Coaxial chimney through which exhaust gases are removed and street air enters.
Non-volatile automation and regulation unit.

This type of installation is equipped with a thermometer, a piezo ignition system and a smoke-air unit.

A distinctive feature of parapet heat generators is the design of the heat exchanger with a copper or steel water heating coil. Spiral turbolizers are installed in the inner part of the heat exchanger, which are designed to reduce the speed of exhaust gases. This design allows you to significantly increase the contact of heated gases with the surface of the heat exchanger, and, consequently, heat transfer.

How to adjust the operation of a gas installation

Many owners of heating equipment ask how to adjust a parapet boiler? We strongly do not recommend adjusting the boiler yourself. We warn you, this instruction is given for informational purposes only.

Let us immediately make a reservation that interfering with the operation of gas equipment is prohibited by law in our country. His self-adjustment operation can lead to reduced efficiency, equipment failure and other undesirable consequences. Condensing boilers must be adjusted by specialists who are licensed and experienced in this type of activity.

Adjusting the operation of the boiler, as a rule, consists of adjusting the gas valve. On the burner block (under decorative panel) there are two adjusting screws: adjusting the maximum and minimum gas pressure.

With the boiler cold, start the pilot burner.
Set the first mode.
If the boiler does not start, then turn the minimum pressure screw (see the data sheet for location) until it starts.

You have adjusted the boiler start. The cutoff is adjusted in the same way.

The condensation heat generator is adjusted using a gas analyzer, the probe of which is installed in a special socket in the chimney. The maximum and minimum power is regulated by turning the damper on the gas valve, based on the readings of the gas analyzer: at maximum power, the carbon dioxide content in the flue gases should not exceed 9.5%; residual oxygen – no more than 4%.

Popular models of heat generators

Today, on the domestic market of climate control equipment you can easily find parapet boiler equipment from several Russian, Ukrainian and European manufacturers. The consumer quite often has a problem with the choice. So, a double-circuit parapet gas boiler: which manufacturer is better?

AOGV 13 P DV "ROSS" is a double-circuit heat generator designed to create autonomous heating and hot water supply in domestic and industrial premises.

This model has a power of 13 kW, which is enough to heat a room of 100 m2. Features of this model: steel heat exchanger; reliable Italian automatic equipment; The system can be connected from any side and can operate on both natural and liquefied gas. Small dimensions allow installation of the unit in any convenient location, but no further than 5 m from the external wall. DHW capacity – 4 l/min. Efficiency – 90%; fuel consumption 1.4 m 3 / h. Cost – 23 thousand rubles.

The heating system connection is universal (left or right), gas supply is only on the right. This device can be mounted on a wall, on the floor, and its small size allows it to be installed under a window sill. DHW capacity – 4.1 l/min; Temperature limits in the heating circuit are 40/90°C. Efficiency – 90%. Gas consumption 1.4 m 3 /h. average cost 19 thousand rubles.

Aton Compact 12.5 MV – Ukraine. This dual-circuit model has become quite popular thanks to the reliable German automation Mertik Maxitrol and high quality assemblies.

The body of the Aton Compact 12.5 MV boiler unit is covered with powder enamel, which reliably protects it from corrosion and makes it visually attractive. Installation power 12.5 kW; fuel consumption no more than 1.4 m 3 / h; DHW productivity – 300 l/hour. Efficiency 90%. The average cost is 18 thousand rubles.

Choice best model and the manufacturer – it’s a matter of taste and financial condition user. But, a larger number of our compatriots believe that the AOGV 13 P DV “ROSS” heat generator is the best of the parapet models.

If you decide to purchase condensing boiler equipment for heating and creating hot water at home, we recommend that you familiarize yourself with the most popular models.

Vaillant AtmoTEC plus VUW 200-5 - wall-mounted condensing double-circuit gas boiler from the famous German manufacturer Vaillant Group.

A special feature of this model is the plate design of the heat exchanger in the DHW unit, which eliminates the appearance of scale. The copper main heat exchanger is coated with Supral, which significantly increases heat transfer. Burner material: chromium-nickel steel. The device is equipped with an LCD display. Thermal power for this model – 22.2 kW; DHW – 9.6 l/min; Efficiency – 98%; Cost – 53.5 thousand rubles.

Chaffoteaux TALIA GREEN EVO SYSTEM 12 FF is a condensing heat generator with a power of 13.3 kW. Designed for autonomous heating and creation of hot water supply in apartments and private houses without a stationary chimney.

The peculiarity of this model is the highest efficiency (99%), efficiency (up to 30%), versatility and automation. This installation can work with a boiler indirect heating. Power consumption 105 W. The average cost is 57 thousand rubles.

BAXI DUO-TEC COMPACT 24 GA is a dual-circuit turbocharged model with a closed combustion chamber, made in Italy.

A special feature of this device is the ability to adapt to fuel quality. The boiler is equipped with a stainless steel burner with preliminary creation of a gas-air mixture and adaptive flame control, due to which a reduced composition of CO and NOx is observed in the combustion products. The efficiency of the installation varies depending on the operating mode
97.6-107.6%. Average cost – 60 thousand rubles.

Based on user reviews, the best condensing boiler in its class is the Vaillant AtmoTEC plus VUW 200-5.

Advice: making the right choice of heating device is a rather difficult task, especially for a person who has not encountered these devices. In any case, before purchasing a gas boiler, consult a professional.