The range of heating boilers presented in retail chains is unusually diverse and wide. Today there is an opportunity to purchase not just a good, but practically a technically perfect unit. Do you think these do not exist? You are wrong. The market is rapidly and confidently conquering condensing boilers - the true embodiment of environmental friendliness and efficiency. Unlike typical gas boilers, which have an efficiency of about 85%, condensing units are able to use fuel more economically - and at the same time demonstrate an efficiency of 95-96%. In this regard, rational Europeans encourage the widespread use of such equipment, even at the legislative level.
Despite the relatively high cost of condensing boilers compared to "conventional designs", the former are successfully and quickly repaid in the face of a continuous rise in gas prices. Condensers are offered by almost all leading manufacturers of heating equipment - Vaillant, Junkers, Ferroli, Baxi, Viessmann.
Condensation of water vapor resulting from the combustion of hydrocarbons is one of the most promising innovative technologies for heat production. That is why we can say with confidence that the future belongs to such units.
A little bit of the history of progressive development
The first "representatives" of condensing boilers appeared in the 50s. Naturally, these models were very, very far from perfect - but they demonstrated real fuel economy even then. Their key disadvantage was the fragility of structural elements in contact with aggressive condensate. Steel and cast-iron heat exchangers suddenly fell into disrepair under the "onslaught" of merciless corrosion, and the device failed.
The world saw condensing boilers, which are as similar as possible to modern ones in design and quality, in the 70s. Their heat exchangers have already been made of stainless steel - a durable and reliable material.
Modern condensing boilers are the embodiment of economy, environmental friendliness and high efficiency. According to many experts, they definitely have a promising future in the heating equipment market.
Various studies and developments in relation to the use of "latent energy of vaporization" were also in the Soviet Union, but for many reasons they did not succeed in becoming massive and global.
The principle of operation of such units
As you know, the principle of operation of any heating boiler is extremely simple:
- Fuel burns out.
- Heat energy is released.
- Thermal energy through the heat exchanger "enters" to the coolant.
Naturally, it is not complete without heat loss. In a traditional gas boiler, the flue gases escape into the atmosphere through the chimney; together with them, part of the unused heat is also lost, because together with the gases, water vapor is also lost, which is formed during the combustion of fuel.
This steam contains exactly that latent energy that condensing boilers are able to store and transfer to the heating system. Extraction of "precious heat" is made possible by the condensation of steam in a special heat exchanger.
The water flow ("return") cools the vapors to the dew point temperature; the energy released during the condensation of vapors is absorbed by the same water.
Condensation heat exchangers are made exclusively of corrosion-resistant materials - stainless steel or silumin, since the practical use of condensate, unfortunately, does not in any way improve its chemically aggressive composition.
Usually, condensate is collected in a special tank built into the unit, and only then is discharged into the sewer. Due to the high aggressiveness of this product of the "vital activity" of the boiler, different norms and rules for its disposal have been adopted in different countries. In some, the condensate is allowed to be sent directly to the sewer, in others it must first be neutralized. Condensate neutralizers are offered by many manufacturers. What are they? These are containers filled with granulate containing calcium or magnesium compounds.
Determination of the actual efficiency of the boiler
Condensing boilers can be safely "introduced" into both traditional and low-temperature systems such as underfloor heating. Working in tandem with the latter, these units demonstrate an unusually high efficiency, since the conditions for condensation are almost ideal.
Competent installation of the "condensing boiler + underfloor heating" system allows you to completely abandon radiators and operate underfloor heating as the main, and not auxiliary, source of heat
We often hear that the efficiency of a condensing boiler can reach a fantastic 109%. Such audacious statements from manufacturers usually amaze people with even the slightest understanding of physics. After all, it turns out that actually perpetual motion machines appeared on sale! In fact, this is an exclusively marketing ploy, designed only to draw attention to the development, and in no way claiming to be scientific truth. But how did this figure come about? It turns out that the efficiency that is "off scale" for 100% is the result of a careful comparison of condensing units with ordinary gas boilers.
"Nonsense" is explained by experts as follows: the efficiency of a typical boiler is calculated by the lowest heat of combustion, excluding heat "flying into the pipe", and with this mathematics is 92-95%. The efficiency of a condensing boiler according to this calculation method is as much as 100%. If you add to it an 8-9% "charge of energy" from the use of the latent heat of condensation, you will get "phenomenal performance". But this is all conditional.
If we make objective calculations, it turns out that the efficiency of standard units is only 84-86%, and of condensing units - a little more than 95%. And this is under ideal conditions.
The condensing boiler can always be equipped with modern weather-compensated automation. It controls the boiler, focusing on the average daily temperature, thereby further increasing the efficiency of the equipment.
Condensing boilers are equipment with a closed combustion chamber. Air supply, removal of combustion products are carried out in a "compulsory manner". They do not need a classic chimney and are reasonably safe. They can be connected to smoke extraction systems such as a two-pipe system, a coaxial chimney, etc.
The relatively low temperature of the combustion products of the condensation units makes it possible to equip the smoke exhaust system for them with the help of plastic pipes. This allows you to save a little, which is good news.
Should you buy a "condensation unit"?
There are wall-mounted and floor-standing condensers. The power of the first, depending on the model, can be up to 120 kW, the second - up to 320 kW or more. If it is necessary to increase the capacity of the installations, it is possible to link the boilers into a cascade.
Depending on the purpose, there are single-circuit and double-circuit condensing boilers. Single-circuit - exclusively for solving the issue of heating; double-circuit is heating + hot water supply.
The cascade connection of condensing boilers allows you to easily organize a compact, easy-to-use boiler room that can demonstrate tremendous savings during the transition period
Still in doubt, is it worth getting a condensing boiler and pinning high hopes on it? An objective look at the advantages and disadvantages of this equipment will help you make the right choice.
Condensing boilers have characteristics that exceed even the most stringent requirements for heating units by the certification authorities. They are recommended for installation in protected and resort areas. The amount of harmful emissions from condensing boilers is 5-8 times less than that of gas boilers
The main advantages of the units include:
- Extremely compact. A condenser with a power of up to 120 kW can always be found in a wall-mounted version. Traditional boilers of the same power are, as a rule, exclusively floor standing, therefore, they take up much more space;
- Light weight;
- High efficiency;
- Deep modulation;
- Saving money for the arrangement of the chimney;
- Environmental friendliness - a minimum of harmful emissions into the environment;
- Reduced vibration;
- Low noise level. A well-thought-out design of the units allows you to almost completely eliminate noise effects. Operation of boilers of this type inside residential premises does not cause any discomfort;
- And most importantly, a significant reduction in gas costs - from 10% to 35%, depending on the "baseline".
Among the disadvantages of the equipment, it is worth noting:
- Very high cost. The condensing unit will cost 40-120% more than a conventional boiler;
- Ineffective in severe frosts. When there is a fierce cold outside, the temperature of the water in the heating system definitely has to be increased. If the temperature of the return water exceeds 60 degrees, the condensing boiler will not be able to perform its miracle function and will switch to the normal boiler mode with an efficiency of about 85%.
Practice shows that, despite all the nuances, condensing boilers are the right choice for thoughtful owners who value smart economy and want to bring maximum thermal comfort to their home. Please note that you can only enjoy a truly efficient system based on a condensing boiler if you trust competent professionals in the selection and installation of equipment.
The operation of a traditional gas boiler entails some loss of thermal energy along with the combustion products. Another negative point is the formation of chemically aggressive condensate, which causes corrosion in the system.
The condensing boiler cools the flue gases below the condensation point. The result is the condensation of water vapor with the release of latent energy to the coolant, which heats up in the boiler.
The principle of operation of condensing boilers
When gas is burned in condensing boilers, the effect of the formation of high-temperature water vapor occurs. The released vapors are concentrated as a liquid on a stainless steel heat exchanger. Standard types of gas heating equipment remove steam along with the rest of the waste products of combustion through the chimney.
When steam accumulates on the primary heat exchanger, heat is generated and returned back to the heating system. This principle of operation of condensing boilers ensures high efficiency rates and efficiency of the entire heating system.
Features of functioning
Condensing boilers are devices with closed combustion chambers. Waste products are forced out. Moreover, they all have a minimum temperature. The presence of an additional heat exchanger makes it possible to increase the resistance to the passage of substances formed during the combustion of fuel. This operating principle makes the natural draft effect impossible. That is why the condensing gas boiler works on the basis of the forced draft principle.
Condensing boilers have a closed combustion chamber with exhaust gases removal by means of special turbines. This has its advantages, since the combustion products can be removed to any place outside the heated building, moving along the supply and outlet channels.
The condensing boiler can be installed in houses without a chimney. This solution is safer compared to the operation of traditional gas boilers, since the combustion process is completely isolated from the room where the heating unit is installed.
Application
Wall-mounted condensing gas boilers, like floor-standing models, are mainly used in radiator heating systems or, if necessary, to equip a warm floor.
A prerequisite for creating a condensation effect is maintaining a certain temperature of the water in the return line. It is important that the coolant remains colder than the temperature at which condensation forms. If this condition is met, the condensing gas boiler will provide maximum operating power throughout the year.
Efficiency
How to achieve the highest efficiency rates by operating a condensing boiler? Compared to conventional gas-fired units, condensing units are designed to use heat from condensation. Thanks to this, it becomes realistic to achieve indicators of efficiency at the level of over 100%.
In the case of natural gas combustion in standard heating boilers, the useless consumption of thermal energy, which could be used with benefit, is about 11%. Assuming that the thermal power of the boiler as a result of fuel combustion is 100% and adding 11% of the latent heat to this indicator, it is possible to achieve a heat output equal to 111%.
In order to obtain high efficiency values when operating a condensing boiler, it is recommended to connect the heating unit to an external ambient temperature sensor. This makes it possible to maintain a stable level of the return water temperature at the required level for effective use of the condensation effect.
Security
Due to the presence of the effect of preliminary connection of gases and air in the corresponding burners, the wall-mounted condensing boiler produces a minimum amount of harmful substances from the exhaust combustion products.
If we draw a parallel with traditional boilers, then here the reduction in the amount of CO and NOx is from 80 to 90%. It is for this reason that, recently, in highly developed countries, condensing units are increasingly used as heating devices.
Advantages
Condensing boilers represent the latest in innovative technology development. Such devices become a profitable solution for the consumer due to a noticeable reduction in fuel consumption. Currently, this technology is considered one of the most economical in space heating. The decrease in gas consumption during the heating season here is about 35%.
Achieving such impressive results is made possible by the following factors:
- the emergence of the process of heat transfer from condensation both in heating mode and in heating water for domestic needs;
- high efficiency rates;
- the ability to achieve a comfortable temperature for living in the absence of significant heat loss;
- availability of ample opportunities for flame modulation.
Progress in the field of production of gas heating equipment has stepped far forward - it is enough to study the functionality of the models on sale to be convinced of this on our own experience. But the technique is assessed not only by its functions, but also by other parameters - these are economy and efficiency. And the most advanced in terms of these characteristics is a condensing gas boiler, which allows to maximize the conversion of gas combustion energy into heat supplied to heating.
In this review, we'll 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 is distinguished by an extremely simple design. There is a gas unit with a valve connected to the burner. Above all this, there is a single heat exchanger, which is responsible for heating the coolant to a given temperature. A mechanical or electronic control system is responsible for maintaining the temperature. The efficiency of the equipment 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 arranged simply, then their two-circuit "colleagues" are arranged a little more complicated - a secondary heat exchanger is added here (or one bithermal one is installed) and a three-way valve. All these units are responsible for the preparation of hot water. The technique is distinguished by good efficiency and allows you to get rid of the need to purchase an additional water heater.
Condensing boilers are even more complex, because they are distinguished by increased efficiency and high efficiency - it reaches 98%. It uses the technology of condensation of moisture from the emitted combustion products. Since they are still full of heat, they can be taken away and put into the heating system. This achieves substantial fuel savings - up to 10% depending on the model and operating conditions.
Gas condensing boilers include the following units:
At the moment, condensing boilers are the most modern and efficient solutions in the field of heating systems.
- Combustion chamber - open or closed. The combustion of the incoming fuel takes place here. Moreover, the overwhelming majority of condensing units are built on the basis of closed chambers, while models with open chambers are isolated;
- The main heat exchanger - here the main selection of thermal energy takes place, which is carried away by the hot coolant;
- The condensing heat exchanger is the most important part of a gas condensing boiler. It is here that moisture condensation occurs with the transfer of heat to the heating system;
- Secondary (or bithermal) heat exchanger and three-way valve - these units are responsible for the operation of the DHW circuit;
- Control electronics - responsible for the operation of all equipment installed on board;
- Drainage - responsible for the drainage of condensate into the sewer.
A condensing boiler is more complex than any other convection unit. But this is what allows him to take maximum heat energy from the combustion products.
The complexity of condensing boilers directly affected their cost - they are at least 30% more expensive than convection counterparts.
The principle of operation of condensing boilers
Let's look at the principle of operation 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 up the chimney, 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 heat energy that we can take 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 gives up the remaining energy, that determines such a high efficiency of the entire system.
- The gas burner generates thermal energy, which is absorbed by the main heat exchanger;
- Combustion products enter a large area condensing heat exchanger;
- The cold heat carrier passing through the condensation exchanger causes the formation of condensation, taking heat energy from the water vapor;
- After that, the coolant enters the main heat exchanger.
For some, it may not be clear where the water vapor comes from. There is nothing strange here - it is formed as a result of the combustion of natural gas. If we take a close look at the chemical formula of the reaction taking place here, then we will see in its results two main components - water vapor and carbon dioxide. It is the steam that contains the heat energy we need.
The condensing boiler is characterized by increased efficiency. This becomes possible due to a more complete extraction of heat from the 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 high efficiency is just a marketing gimmick aimed at increasing sales. In reality, the efficiency reaches 98%.
When creating the 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 condensing one, and only then into the main heat exchanger.
In other words, in order to be able to save on gas fuel due to 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
The condensing boiler is a unique piece of equipment created by the developers of heating technology. It is environmentally friendly and saves on gas fuel. Condensing boilers are widespread in European countries, where people care about their welfare and nature. And there they are the leaders in consumer demand.
On the territory of Russia, a condensing boiler is a rarity - consumers are not ready to change equipment at breakneck speed for a cleaner, from the point of view of the environment, technology. And the whole point is in its high cost, because individual models are up to two times more expensive. But those who know how to count and are good with math know that the initial cost is justified by saving on fuel. You just need to properly configure the equipment so that it works in the optimal temperature regime.
Let's take a look at the pros and cons of a condensing boiler - let's start with the positives:
If it seems to you that 10% savings are not so great, then just calculate how much money you will spend on gas at least in the next 5-7 years. We assure you that the numbers will unpleasantly surprise you.
- Savings on gas fuel - here we will find 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 / h, while for similar convection models it is about 2.2 cubic meters. m / hour;
- Reducing the burden on the environment - the more efficiently the fuel is processed, the better for the environment. It is bad that not every person understands this;
- Low temperature of combustion products - since thermal energy is taken almost completely, the temperature of the gases at the outlet of the gas boiler is extremely low;
- The possibility of unhindered use with water floors - they just need a low temperature of the coolant. In traditional high temperature heating, gas condensing boilers will be a waste of money;
- A wide range of models - any power (up to 50 kW and more), single-circuit and double-circuit, floor-standing and wall-mounted, with open (rare) and closed combustion chambers.
There are also disadvantages:
- The low temperature of the coolant will require recalculation of the number of sections in the radiators - there is no getting away from this. But you can act differently by installing small-sized baseboard convectors or underfloor heating instead of traditional batteries;
- The 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 drainage - its surplus is removed to the sewer system;
- Decrease in efficiency with increasing temperature - if suddenly you want to add gas to keep the rooms warmer, efficiency will start to drop rapidly;
- Volatility - all gas condensing boilers require electricity. Therefore, consumers will have to take care of the reserve;
Due to their design features and the principle of operation, condensing boilers use fuel energy much more efficiently and more economically than traditional gas-fired units. Although the price of condensing equipment is still high, homeowners are increasingly opting for it. And this is not surprising - the boiler efficiency reaches up to 98%, and gas savings reaches 20%. Experts say that condensation technology is the future.
The principle of operation of condensing boilers
The cost of fuel is getting higher from year to year, so energy-saving technologies are steadily gaining popularity. Condensing boilers appeared in the middle of the last century, but they were not immediately able to win the trust of consumers. At the time, the instruments were unreliable and manufacturers had to tweak their designs. As a result, they have ensured that these models of heating cats have taken a leading position in the market.
An interesting fact is that European countries stimulate and support their citizens who decide to buy a condensing gas boiler by providing loans at minimal interest.
A conventional natural gas heating boiler uses only a fraction of the energy from the combustion of the fuel. Waste gases, which have a sufficiently high temperature and powerful potential, are discharged into the atmosphere through the chimney, giving off unused heat to the outside air. The condensing gas unit more efficiently uses the heat resources released not only during the combustion of gas, but also during the condensation of water vapor contained in the smoke. Steam entering a separate heat exchanger, when cooled, turns into a liquid called condensate. This releases a certain amount of heat. Moisture is discharged into a condensate trap, and heat energy is discharged into the heating system.
A conventional gas boiler during operation uses a lower heat of combustion, while equipment of a condensing type uses a higher one, consisting of the heat released during the combustion of fuel and the heat that appears during condensation. This is the more efficient use of natural gas and efficiency, as well as increased efficiency indicators, which differ not only in floor-standing units, but also in wall-mounted heating devices.
The equipment of the condensing type under consideration is perfect for both radiator heating and hot water supply systems, and for the installation of a "warm floor".
Construction of condensing heating devices
Any of the boilers has a heat exchanger in which the coolant is heated, which then enters the heating system of the house through the piping. Gas boilers of the condensing principle of operation are equipped with two heat exchangers, the first of which operates according to the traditional scheme, and the second, condensing, is switched on later.
The secondary heat exchanger is a structure of pipes of complex cross-section with spiral fins. This shape allows you to significantly increase the area in contact with the steam. The flue gases in the additional heat exchanger heat the heating medium coming from the return line. At this point, the water vapor cools down to the dew point, resulting in condensation.
In other words, in a condensing boiler, part of the energy is returned for reuse, whereas during the operation of a conventional boiler, it irretrievably escapes into the atmosphere along with the steam.
For the manufacture of secondary heat exchangers, stainless steel is used, as well as coatings from aluminum-silicon alloys called silumin. This protects the device from chemically aggressive condensation.
Gas condensing boilers are equipped with high-tech burners. Their peculiarity lies in the fact that in the combustion mode they provide constant control over the mixing proportions of the gas-air mixture, observing the optimal ratio. The design of the heating devices has a closed combustion chamber, isolated from the room. Therefore, the considered boilers are relatively safe equipment.
Externally, energy-saving and traditional gas boilers are practically no different. Manufacturers produce wall and floor models in single-circuit and multi-circuit designs. But you should pay attention to the fact that the condensing equipment has a higher power with the same dimensions. For example, wall-mounted boilers using the heat of air steam can have a capacity of up to 110 kW, while conventional gas-fired units with a capacity of more than 40 kW are already produced in a floor-standing version.
Modern models of heating boilers using the condensing principle of operation are produced in two versions - with dry or wet heat transfer. The first option is intended for residential buildings, and the second, more efficient and expensive one, is for boiler houses. But boilers with wet heat transfer are not yet fully developed, because are still under development.
Condensate disposal
The condensing boiler produces a fairly large volume of condensate per day. It depends on the capacity of the equipment and can be 30 liters or more. It is not allowed to drain aggressive liquid directly into the domestic sewage system, therefore, manufacturers equip modern gas heating devices with neutralizers.
The additional device is a separate reservoir for acidic condensate. It passes through a layer of alkali metals (magnesium and potassium), resulting in a chemical reaction. As a result, the condensate decomposes into carbon dioxide and water, which can already be drained into the sewerage system.
How beneficial is the use of condensing boilers
There are many opinions about the economic benefits of using condensing gas equipment in a domestic environment. The fact is that for consumers in Russia the price of gas is provided significantly lower than for residents of European countries. Therefore, some experts claim that condensing boilers will pay off in our conditions for at least ten years. But this is not true.
First, gas is not as cheap as we would like it to be. Secondly, the reviews of the owners of heating boilers indicate that significant savings can be seen as early as 2-4 years of operation. This period depends on the technical characteristics of the equipment, such as power, and on the optional equipment.
For clarity, some examples should be considered.
A budget option
A condensing boiler with a built-in heat exchanger for a private house, assuming a heat load of up to 30 kW with the simplest wiring and connecting only heating radiators, will cost a third more than a traditional boiler. But operating costs at maximum loads will make it possible to return this difference in 3.5-4 years, taking into account the annual increase in gas prices. In the future, the condensing boiler will begin to significantly save fuel costs, becoming more profitable every year.
Advanced option
The price of a traditional boiler (taking into account the purchase of a set of additional devices) for a house that requires a heat load of about 35 kW, with a multi-circuit heating distribution system and the presence of a 200-liter hot water tank will be higher than condensing gas equipment. Therefore, there is no need to talk about payback here. It turns out that a condensing boiler designed for medium heat loads begins to save the owner's money from the first day.
Highly advanced option
In this category, you can consider multi-circuit boilers with a heat load of up to 60 kW. In this case, it will be necessary to complete the already condensing boiler, so its price will be 15-20% higher. But the difference, taking into account the rise in gas prices, will be equal earlier than with the budget option. It will be possible to talk about payback in 2.5-3 years.
Feedback from experts and consumers suggests that condensing heating boilers are preferred by those owners who know how to count their money. They understand that in addition to saving on gas bills, such equipment will last at least twice as long as a conventional gas appliance.
But do not forget that the efficiency of condensing equipment will depend on several factors:
- boiler age;
- the correct ratio of the heated volume and the power characteristics of the unit;
- using modern gas burners.
Installation of floor-standing gas boilers
In the floor-standing version, high-power boilers are made. They are installed in separate rooms, where it is possible to organize additional ventilation. The installation process is carried out in stages.
- At the stage of preparatory work, a foundation is made in the form of a concrete cushion with a height of 100-200 mm or a support frame is installed.
- The places of connection to the boiler equipment of the chimney, supply and return pipes of heating are determined and organized.
- A gas boiler is installed on a prepared base on a horizontal level. Its adjustment is made with screw feet.
- The unit is connected to the pipelines of the coolant circulation system. This takes into account that double-circuit and multi-circuit boilers have additional pipes and flexible piping.
Before entering the heating boiler, a special coarse filter must be installed on the return pipe to prevent scale or rust from entering the heat exchanger.
- The unit is connected to the gas pipeline using copper pipes or flexible hoses. A valve is mounted on the inlet pipe. The branch pipe is connected to the chimney.
- The seams and joints are checked for tightness, and the gas pressure in the pipeline is checked for compliance with regulatory requirements.
Regardless of the model, floor-standing gas boilers are allowed to be installed in rooms with a ceiling height of at least two meters. A single unit requires a minimum volume of 7.5 m3 and a mandatory ventilation opening for external air intake.
The minimum distance from a wall made of non-combustible materials is allowed to be 100mm. Roofing steel with a thickness of at least three millimeters is used as an insulating material.
Non-combustible coverings are required on the floor under the gas boiler. This could be:
- steel sheet;
- tile;
- a natural stone;
- cement strainer;
- expanded clay concrete slabs.
Installation of wall-mounted boilers
Wall-mounted appliances are installed after preparing the electrical wiring and connections to the hydraulic and gas circuits, which is done using the supplied templates. Before that, it is determined:
- location of the heater;
- the possibility of a communications device;
- the admissibility of organizing the correct removal of combustion products.
It is required to fasten the wall-mounted heating boiler to a reliable base. In most cases, load-bearing walls or a specially installed frame in the form of frames, consoles, hangers, racks, etc. are used for this. Manufacturers provide a range of accessories and fittings that are supplied complete with the equipment or purchased separately. Also, the wall-mounted unit can be fixed to a vertical fence using a mounting frame made for a specific heater model. Its use in combination with decorative panels and covers allows you to harmoniously fit the condensation technique into the interior of the room.
After installing the boiler on the wall, proceed to its direct connection to the supplied engineering networks and communications.
The branch pipe responsible for the removal of carbon monoxide gases is connected through corrugated pipes with a chimney. At the same time, their sharp bends are not allowed. The chimney should not be located less than 100mm from flammable surfaces. In any case, it will be better to isolate them.
Valves are installed on the gas nozzles and the gas pipelines are checked for tightness. The wall-hung boiler must be connected by a specialist, carrying out appropriate tests and blowing out the pipes.
To be able to connect the equipment to the 220V power grid, you will need to install an outlet and a stabilizer. Do not forget about the grounding of condensing boilers, as well as the fact that contact of the cable with hot elements can lead to its melting and failure. The safety requirement must be respected unquestioningly.
The water circuit is connected to the wall-mounted boiler according to the corresponding diagrams supplied with the equipment.
Features of chimneys for condensing boilers
Ready-made chimneys made of plastic or aluminum are installed on wall-mounted and floor-standing condensing boilers. By design, they can be:
- coaxial, representing a "pipe-in-pipe" design;
- two-pipe, divided into a flue and air intake segment.
The low temperature of the exhaust gases leaving the chimney allows the use of plastic in the exhaust system. At a temperature of 35-70 degrees, it does not deform, does not melt and does an excellent job with its functions.
This circumstance significantly helps when replacing an old boiler with a brick chimney with new equipment. A conventional gas boiler will require the dismantling of the old chimney, since temperature fluctuations and aggressive condensate will cause the masonry to collapse too quickly. To prevent an emergency, you will have to think in advance about installing an anti-corrosion, gas-tight stainless steel chimney or polymer liners, the price of which is quite high.
For a condensing boiler, you can limit yourself to wrapping the old chimney with plastic, which will come out much cheaper.
Condensing boiler myths
The popularity of any product always gives rise to multiple rumors and myths that do not always reflect reality. Condensing boilers, both wall-mounted and floor-standing, are no exception. Let's try to figure out some of them.
Price
Experts say that condensing boilers are more expensive than traditional gas units. But this is only with a cursory glance at the price tag or price list. Having sorted out the issue, you can understand that the equipment differs not only in price and version (wall or floor, single or double-circuit devices), but also in thermal power.
Paying attention to the technical characteristics of gas boilers of different principles of operation, as well as comparing two units with the same performance and capabilities, you can make sure that the final price of traditional equipment is often higher than the condensing one. And if we take into account that additional devices must be purchased for ordinary gas boilers, the price of which can be significant, then the question of a higher cost of condensing technology will disappear by itself.
Efficiency
Many manufacturers claim that their condensing boilers are more than 100% efficient. This statement evokes a twofold feeling. On the one hand, it is quite attractive to consumers, and on the other hand, it causes confusion.
The use of additional heat, of course, increases the efficiency of using this type of equipment and increases the efficiency. But talking about a coefficient exceeding 100% can only be conditional.
The fact is that to facilitate the comparison of two types of gas heating equipment, the calculation of the efficiency is carried out according to the method for determining the indicator for traditional boilers that use only the lowest heat of combustion. And here the heat of condensation is not taken into account, which adds 7-9% to the efficiency. Condensing units use one hundred percent of the lower heat and its part, which has arisen as a result of the condensation process, from which the figure of 107-109% is added. In fact, the efficiency does not rise above 98%.
Chimney
Despite the opinions about the need for a device for condensation devices for chimneys made of acid-resistant materials, the price of which is quite high, they differ little from ordinary chimneys installed in systems of gas units with a closed firebox.
Waste combustion products are discharged forcibly, therefore, the considered boilers can be connected to various flue systems. The main thing is that the tightness of the structure is observed.
Condensate
Many consumers are sure that during the operation of the boiler there are problems associated with the appearance of condensate. But manufacturers of condensing equipment include systems for neutralization and disposal of aggressive moisture in the design of devices. For conventional gas units, in the chimneys of which, although in smaller quantities, condensate is present, diverters and neutralizers are installed additionally.
Famous manufacturers
The heating equipment market is diverse and extensive. Domestic and foreign manufacturers offer a huge range of boilers that differ in their dimensions, power and type of fuel used. Several companies can be distinguished among the most famous manufacturers of condensation technology.
The German company appeared in 1917 as a workshop for the production of agricultural machinery, and 10 years later its founder Johann Wiessmann developed and produced the first boiler. Until now, the company is headed by one of the family members, already in the third generation.
Today Viessmann includes several companies specializing in heating systems as well as ventilation and refrigeration systems. Its products are mostly exported, and production sites are located in 11 countries. The company produced the first condensing boiler in 1992.
A small private company was founded by the Prussian engineer Johan Weillant in 1874. Thanks to the outstanding abilities of the owner, she quickly achieved success. Since 1894, the company began producing gas equipment, and today the Vaillant Group, which has factories in 7 countries, is known all over the world, including for its developments in the field of energy-saving equipment.
Bosch
The workshop, founded in 1886 by the German inventor and researcher Robert Bosch, had nothing to do with heating boilers for a long time. Only in 1929, the founder of the company made a decision to restructure it and move to a broader field of activity. Since that time, many enterprises have joined the structure of the corporation, including firms for the production of household boiler equipment.
The history of the German company Buderus began in 1731, when its founder Johann Wilhelm Buderus rented a small metallurgical plant, where cast iron parts for furnaces were produced. In 1898, the company received a patent for its own sectional boilers, and in 1981 - presented the condensing cast iron equipment. Since 2003, the Buderus trademark has been owned by the Robert Bosch GmbH group of companies.
Baxi
The company was founded in 1866 in England. It was founded in partnership between Richard Baksendhal and Joseph Hild, and the Baxi trademark was used only in 1930 when one of the heating systems was released. Today, boilers of Italian production Baxi S.p.A., belonging to one of the enterprises of the Baxi Group holding, are entering the Russian market.