The range of heating boilers presented in retail chains is extremely diverse and wide. Today it is possible to purchase not just a good, but practically technically perfect unit. Do you think they don't exist? You're wrong. The market is rapidly and confidently conquered by 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 operation of such equipment, even at the legislative level.
Despite the relatively high cost of condensing boilers compared to "conventional designs", the former successfully and quickly pay off in the face of continuous growth in gas prices. Almost all leading manufacturers of heating equipment offer condensers - 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 such units are the future.
A little history of progressive development
The first "representatives" of condensing boilers appeared in the 50s. Naturally, these models were very, very far from perfect - but the real fuel economy was demonstrated 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 ruthless corrosion, and the device failed.
Condensing boilers, as similar as possible to modern ones in design and quality, the world saw in the 70s. Their heat exchangers were already made of stainless steel - a durable and reliable material.
Modern condensing boilers are the epitome 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 regarding the use of "latent energy of vaporization" were 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:
- The fuel burns out.
- Thermal energy is released.
- Thermal energy through the heat exchanger "enters" the coolant.
Naturally, it does not do without heat loss. In a traditional gas-fired boiler, the flue gases “disappear” into the atmosphere through the chimney; along with them, a part of the unused heat also goes away, because water vapor, which is formed during the combustion of fuel, is also lost along with the gases.
This steam just contains the hidden energy that condensing boilers can store and transfer to the heating system. Extraction of "precious heat" becomes possible due to the condensation of steam in a special heat exchanger.
The flow of water ("return") cools the vapor to the dew point temperature; The energy released during the condensation of vapors is absorbed by the same water.
Heat exchangers of condensers are made exclusively from corrosion-resistant materials - stainless steel or silumin, since the practical use of condensate, unfortunately, does not improve its chemically aggressive composition.
Usually, condensate is collected in a special tank built into the unit, and only then is it discharged into the sewer. Due to the high aggressiveness of this product of the “life activity” of the boiler, different standards and rules for its disposal have been adopted in different countries. In some, condensate is allowed to be sent immediately 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 granules containing calcium or magnesium compounds.
Determining the real efficiency of the boiler
Condensing boilers can be safely "implemented" in both traditional and low-temperature systems like 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 rather than an auxiliary source of heat
We often hear that the efficiency of a condensing boiler can reach a fantastic 109%. Such bold statements by manufacturers usually lead to amazement of people even slightly versed in physics. After all, it turns out that actually perpetual motion machines appeared on sale! In fact, this is only a marketing ploy, designed only to draw attention to the development, and in no way claims to be scientific truth. But how did such a number come about? It turns out that the efficiency that goes over 100% is the result of a careful comparison of condensers with ordinary gas boilers.
The “nonsense” is explained by experts as follows: the efficiency of a typical boiler is calculated according to the lower calorific value, without taking into account the heat “flying into the pipe”, and with such mathematics it 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% "energy charge" 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 that of condensing units is a little over 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 "forced manner". They do not need a classic chimney and are quite safe. They can be connected to such smoke exhaust systems as a two-pipe system, a coaxial chimney, etc.
The relatively low temperature of the combustion products of condensers makes it possible to equip a smoke exhaust system for them using plastic pipes. This allows you to save a little, which is good news.
Is it worth it to buy a "condenser"?
Condensers are wall-mounted and floor-mounted. 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, boilers can be linked in 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 - this is heating + hot water.
The cascade connection of condensing boilers makes it easy to organize a compact, easy-to-use boiler room that can demonstrate tremendous savings during the transition period
Still in doubt, is it worth it to acquire a condensing boiler and place 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 certification bodies. They are recommended for installation in protected and resort areas. The amount of harmful emissions from condensing boilers is less than that of gas boilers by 5-8 times
The main advantages of the units include:
- Ultimate compactness. 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 on 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. The 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 "initial conditions".
Of the minuses of the equipment, it is worth noting:
- Very high cost. The condenser 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 return water temperature exceeds 60 degrees, the condensing boiler will not be able to perform its miracle function and will switch to 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 savings and are eager 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 combustion products. Another negative point is the formation of chemically aggressive condensate, which causes corrosion in the system.
The condensing boiler cools the combustion products below the point of condensation. The result is the condensation of water vapor with the return of latent energy to the coolant, which is heated in the boiler.
The principle of operation of condensing boilers
When gas is burned in condensing-type 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 combustion products through the chimney.
When accumulations of steam form on the primary heat exchanger, heat is released, which is returned back to the heating system. This principle of operation of condensing boilers ensures high efficiency and efficiency of the entire heating system.
Features of functioning
Condensing type boilers are devices with closed combustion chambers. Waste products are discharged outside by force. And 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 principle of operation makes the effect of natural draft 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 removed by special turbines. This has its advantages, since the products of combustion can be removed to any place outside the heated building, moving along the supply and discharge channels.
You can install a condensing boiler 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, as well as floor-standing models, are mainly used in radiator heating systems or, if necessary, arranging a warm floor.
A prerequisite for creating the effect of condensation 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 produce maximum power throughout the year.
Efficiency
How to achieve the highest efficiency values when operating a condensing boiler? Compared to conventional gas appliances, condensing units are designed to use the heat from condensation. Thanks to this, it becomes possible to achieve efficiency indicators at levels above 100%.
In the case of natural gas combustion in standard heating boilers, the useless consumption of thermal energy that could be used with benefit is about 11%. Assuming that the heat output of the boiler as a result of fuel combustion is 100% and adding 11% latent heat to this indicator, a heat output of 111% can be achieved.
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 return water temperature at the required level for effective use of the condensation effect.
Safety
Due to the effect of preliminary combination of gases and air in the corresponding burners, the wall-mounted condensing boiler produces a minimum amount of harmful substances from the waste products of combustion.
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 have been increasingly used as heating devices.
Advantages
Condensing boilers represent the latest developments in innovative technology. 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 due to the following factors:
- the emergence of the process of heat transfer from condensation both in the heating mode and in heating water for domestic needs;
- high efficiency;
- the possibility of achieving a comfortable temperature for living in the absence of significant heat losses;
- wide possibilities for flame modulation.
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 for yourself. But the technique is evaluated not only by functions, but also by other parameters - this is economy 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:
- Structural features of gas condensing boilers;
- How does condensing equipment work;
- 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
A conventional gas boiler is distinguished by an extremely simple design. Here is a gas unit with a valve connected to the burner. Above all this hangs a single heat exchanger responsible for heating the coolant to a predetermined 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 simple, then their double-circuit "colleagues" are a little more complicated - here a secondary heat exchanger is added (or one bithermic one is installed) and a three-way valve. All these nodes are responsible for the preparation of hot water. The technique has a good efficiency and allows you to get rid of the need to purchase an additional water heater.
Condensing boilers are even more complicated, because they are characterized by increased efficiency and high efficiency - it reaches 98%. It uses the technology of condensation of moisture from the released 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 components:
At the moment, condensing boilers are the most modern and efficient solutions in the field of heating systems.
- The combustion chamber is open or closed. This is where the combustion of the incoming fuel takes place. Moreover, the vast majority of condensing units are built on the basis of closed chambers, while models with open chambers are single;
- 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 condensation of moisture occurs with heat transfer to the heating system;
- Secondary (or bithermic) heat exchanger and three-way valve - these nodes 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 removal of condensate into the sewer.
A condensing boiler is more complex than any other convection unit. But this is what allows him to take the maximum thermal energy from the combustion products.
The complexity of condensate 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 touch 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 thermal 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 off 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 coolant passing through the condensation exchanger causes the formation of condensate, taking thermal energy from the water vapor;
- After that, the coolant enters the main heat exchanger.
For some, it may remain unclear 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 carefully look at the chemical formula of the reaction taking place here, we will see two main components in its results - this is 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 a more complete removal of heat from the combustion products. Manufacturers claim that the efficiency is up to 115%, but you can’t go against the laws of physics - you can’t get more energy than it was spent. 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 have done 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 fly into the atmosphere, and the efficiency will drop. Therefore, the coolant first enters the condensing, 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 heat engineering developers. It takes care of the environment and saves on gas fuel. Condensing type boilers are widespread in European countries, where people care about their well-being and nature. And there they are leaders in consumer demand.
On the territory of Russia, a condensing boiler is a rarity - consumers are not ready to headlong change equipment for cleaner, from an environmental point of view, equipment. And the thing is its high cost, because some models cost up to two times more. But those who know how to count and are friends with mathematics know that the initial costs are justified by saving on fuel. You just need to properly configure the equipment so that it works at the optimum temperature.
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 a 10 percent savings 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, the numbers will surprise you unpleasantly.
- Savings on gas fuel - here we are waiting for real savings, reaching 10% and even a little more. That is, if we work hard to reduce heat losses in our homes and install a condensing boiler, gas fuel savings 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 approximately 2.2 cubic meters. m/hour;
- Reducing the burden on the environment - the more efficiently the fuel is processed, the better for nature. It is bad that not every person understands this;
- Low temperature of combustion products - since the thermal energy is taken away 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 and wall, with open (rare) and closed combustion chambers.
There are also disadvantages:
- The low temperature of the coolant 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-sized plinth 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 excess is removed into the sewer system;
- Decrease in efficiency with an increase in temperature - if you suddenly want to add gas so that it is warmer in the rooms, the efficiency will begin to drop rapidly;
- Energy dependence - all gas condensing boilers need electricity. Therefore, consumers will have to take care of the reserve;
Due to their design features and principle of operation, condensing boilers use fuel energy much more efficiently and economically than traditional gas units. Despite the fact that the price of condensing equipment is still high, homeowners are increasingly opting for it. And this is not surprising - the efficiency of the boiler reaches up to 98%, and gas savings reach up to 20%. Experts say that condensing technology is the future.
The principle of operation of condensing boilers
The cost of fuel is getting higher every year, so energy-saving technologies are steadily gaining popularity. Condensing boilers appeared in the middle of the last century, but they could not immediately win the trust of consumers. At that time, the devices were unreliable, and manufacturers had to refine their design. As a result, they have achieved that these models of heating cats have taken a leading position in the market.
An interesting fact is that European countries encourage 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 part of the energy obtained from the combustion of fuel. Exhaust 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 smoke. The steam entering a separate heat exchanger, being cooled, turns into a liquid called condensate. This releases some heat. Moisture is removed to the condensate collector, and thermal energy - to the heating system.
A conventional gas boiler uses the lower calorific value during operation, while condensing-type equipment uses the higher one, consisting of the heat released during the combustion of the 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 distinguish not only floor units, but also wall-mounted heating devices.
The condensing type equipment in question is excellently suited for both radiator heating and hot water systems, and for a “warm floor” device.
The design 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 put into operation later.
The secondary heat exchanger is a structure of pipes of complex cross section with helical fins. This form allows you to significantly increase the area in contact with steam. Flue gases in an additional heat exchanger heat the coolant coming from the return line. At this point, the water vapor cools down to its dew point, resulting in condensation.
In other words, in a condensing boiler part of the energy is returned for reuse, while in the operation of a conventional boiler it irretrievably escapes into the atmosphere along with 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 condensate.
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 proportions of mixing the gas-air mixture, observing the optimal ratio. The design of heating devices has a closed-type combustion chamber, isolated from the room. Therefore, the boilers in question are relatively safe equipment.
Externally, energy-saving and traditional gas boilers are practically no different. Manufacturers produce wall models and floor models, in single-circuit and multi-circuit versions. But you should pay attention to the fact that condensing equipment has more power with the same dimensions. For example, wall-mounted boilers that use the heat of air vapor can have a power of up to 110 kW, while conventional gas units with a capacity of more than 40 kW are already available in the floor version.
Modern models of heating boilers using the condensing principle of operation are available in two versions - with dry or wet heat transfer. The first option is intended for residential buildings, and the second, more efficient and expensive, for boiler houses. But boilers with wet heat transfer have not yet been fully developed, because. are still under development.
Condensate disposal
During the day, the condensing boiler produces a fairly large volume of condensate. It depends on the power of the equipment and can be 30 or more liters. It is not allowed to drain aggressive liquid directly into the domestic sewer, therefore manufacturers equip modern gas heaters with neutralizers.
An additional device is a separate tank into which acid condensate enters. 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 sewer system.
How profitable is the use of condensing boilers
There are many opinions about the economic benefits of using condensing gas equipment in domestic conditions. The fact is that for consumers in Russia, the price of gas is provided much lower than for residents of European countries. Therefore, some experts argue that condensing boilers in our conditions will pay off for at least ten years. But this is not true.
First, gas is not as cheap as we would like. Secondly, feedback from the owners of heating boilers suggests 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 with a heat load of up to 30 kW with the simplest wiring and connection of only heating radiators will cost a third more than a traditional boiler. But operating costs at maximum load 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 (including the purchase of a set of additional devices) for a house requiring a heat load of approximately 35 kW, with a multi-circuit heating distribution system and 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 the condensing boiler, designed for medium heat loads, from the first day begins to save the owner's money.
Highly advanced version
In this category, you can consider multi-circuit boilers with a heat load reaching 60 kW. In this case, it will be necessary to complete the condensing boiler already, so its price will be 15-20% higher. But the difference, taking into account the rise in gas prices, will equalize 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;
- use of modern gas burners.
Installation of floor gas boilers
In the floor version, boilers of high power are made. They are installed in separate rooms in which there is the possibility of organizing 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 100-200 mm high or a support frame is installed.
- The places of connection to the boiler equipment of the chimney, supply and return heating pipes are determined and organized.
- A gas boiler is installed on the prepared base at a horizontal level. Its adjustment is made by screw legs.
- 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 outlet pipe is connected to the chimney.
- Check the seams and connections for tightness, and the gas pressure in the pipeline - for compliance with regulatory requirements.
Regardless of the model, floor gas boilers are allowed to be installed in rooms with a ceiling height of at least two meters. A single unit requires a minimum space volume of 7.5 m3 and a mandatory vent to allow air to flow in from outside.
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.
On the floor under the gas boiler, non-combustible coatings are required. It 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 supply and connections to the hydraulic and gas circuits, which is done using the attached templates. Before this is determined:
- location of the heater;
- possibility of communication device;
- the admissibility of organizing the correct removal of combustion products.
It is required to fix 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, suspensions, racks, etc. are used for this. Manufacturers provide a range of fixtures and fittings supplied 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 model of the heater. Its use in a set with decorative panels and covers allows you to harmoniously fit the condensing equipment into the interior of the room.
After installing the boiler on the wall, they proceed to its direct connection to the connected engineering networks and communications.
The branch pipe responsible for the removal of carbon monoxide is connected through corrugated pipes to the chimney. At the same time, their sharp bends are not allowed. The chimney must not be located at a distance of less than 100mm from flammable surfaces. In any case, it will be better to isolate them.
Valves are installed on the gas pipes and the gas pipelines are checked for tightness. The wall-mounted boiler must be connected by a specialist, carrying out appropriate tests and purging pipes.
To be able to connect the equipment to the 220V power grid, you will need to install an outlet and have 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 observed unquestioningly.
The water circuit is connected to the wall-mounted boiler, adhering to the appropriate diagrams supplied with the equipment.
Features of chimneys for condensing boilers
Ready-made chimney pipes made of plastic or aluminum are installed on wall-mounted and floor-standing condensing-type boilers. By design, they can be:
- coaxial, which is a "pipe in pipe" design;
- two-pipe, divided into a smoke exhaust and air intake segment.
The low temperature of the exhaust gases escaping through 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 perfectly copes 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, because due to temperature fluctuations and aggressive condensate, the masonry will 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 lining the old chimney with plastic, which will come out much cheaper.
Myths about condensing boilers
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 understand some of them.
Price
Experts say that condensing boilers are more expensive than traditional gas units. But this is only with a superficial 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-mounted or floor-standing, single- or double-circuit devices), but also in terms of 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 see that the final price of traditional equipment is often higher than condensing. And if we take into account that conventional gas boilers require additional devices, the price of which can be significant, then the question of a higher cost of condensing equipment will disappear by itself.
efficiency
Many manufacturers claim that their condensing boilers are over 100% efficient. This statement is ambivalent. On the one hand, it is quite attractive to consumers, and on the other hand, it causes bewilderment.
The use of additional heat, of course, raises the efficiency of the use of this type of equipment and increases the efficiency. But talking about a coefficient exceeding 100% can only be conditional.
The fact is that in order to facilitate the comparison of two types of gas heating equipment, the efficiency calculation is carried out according to the method for determining the indicator for traditional boilers using only the lowest calorific value. And here the heat of condensation is not taken into account, which adds 7-9% to the efficiency. Condensation plants use 100% lower heat and part of it that has arisen as a result of the condensation process, which adds up to an indicator of 107-109%. In fact, the efficiency does not rise above 98%.
Chimney
Despite the opinions about the need for devices for condensing chimneys made of acid-resistant materials, the price of which is quite high, they are not much different from conventional chimneys installed in closed-fired gas unit systems.
Waste combustion products are removed forcibly, so the boilers in question can be connected to various smoke exhaust systems. The main thing is to respect the tightness of the structure.
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 neutralizing and utilizing aggressive moisture in the design of devices. For conventional gas units, in the chimneys of which, although in smaller quantities, condensate is present, vents and neutralizers are installed additionally.
Notable Manufacturers
The market for heating equipment 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. Among the most famous manufacturers of condensing equipment, there are several companies.
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 enterprise is headed by one of the representatives of the family, already in the third generation.
Today, Viessmann includes several companies specializing in heating systems, as well as ventilation and refrigeration systems. Its products are mainly produced for export, 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 Vaillant in 1874. Thanks to the extraordinary 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-researcher Robert Bosch, had nothing to do with heating boilers for a long time. Only in 1929, the founder of the company decided to restructure it and move to a wider area of activity. Since that time, many enterprises have joined the structure of the corporation, including firms manufacturing 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, cast-iron condensing equipment was introduced. Since 2003, the Buderus trademark has been owned by the Robert Bosch GmbH group of companies.
Baxi
The company appeared in 1866 in England. It was founded in partnership between Richard Baxendael and Joseph Heald, and the Baxi trademark was used only in 1930 when one of the heating systems was released. Today, boilers of the Italian production Baxi S.p.A., belonging to one of the enterprises of the Baxi Group holding, are entering the Russian market.