Installation of a condensing gas boiler. Condensing gas boiler: features and benefits. Connecting the boiler to a gas boiler

In European countries, traditional (Convection) boilers have long been abandoned. What is the reason for this approach? Europeans are solid people and know how to count benefits, but if they use condensing boilers, so there is an advantage here. In what way can it be expressed?

Pros and cons of condensing boilers

The high efficiency of boilers is ensured by the combustion gas, which emits a large number of water vapor and has a very high temperature. The boiler equipment supplies this “additional heat” to the boiler heat exchanger, which provides additional heat removal.
Unlike a traditional boiler, a condensing boiler has a modulation range of 6 kW, resulting in reduced consumption (20-30% depending on the average winter temperature).
Thanks to closed cell combustion is safer and more environmentally friendly.
Small weight and dimensions of the boiler.
Low noise and vibration levels.

From these indicators it is clear why practical Europeans opt for condensing boilers, although they are somewhat more expensive than usual. In Russia, according to the owners of such boilers, their payback due to gas savings comes to 2 – 4 year of operation.

Installation of condensing heating boilers

The use of a condensing boiler in the heating system must be included in the project. Since it differs significantly from the usual wiring, pipe diameter and chimney feature.

As a rule, wall-mounted boilers are used for heating private houses. Their power is enough to heat the house, and their compact size allows you to place it in any convenient place, no need to build a separate boiler room. For example, a boiler with dimensions of only 589x368x364 is able to heat a house up to 240 m².

Installation of condensing heating boilers is possible on any reliable base. For this, either the fasteners that come with the kit are used, or a mounting frame is made. The use of such a frame allows you to organically fit this boiler into any interior.

Having fixed the boiler on the wall, proceed to connect the communications in accordance with the relevant diagrams. The output of carbon monoxide is carried out through the chimney, the pipe must be insulated and there should not be flammable surfaces nearby.

It is wiser to use such a highly efficient boiler with systems that also have high performance. For example, with Kermi radiators, which have the most high level heat transfer and heating system known as the Tichelmann loop.

Loop heating installation has a number of advantages:
System balance. No additional regulators required.
High efficiency due to equal water flow throughout the system.
Uniform heating of radiators.

These effects are achieved due to the fact that the return heating main starts from the first radiator, reaches the final one, and from there it is fed to the boiler. As a result, all radiators function as a single unit and, regardless of the distance from the boiler, they heat up the same way.

Decided to choose a classic gas boiler for heating, but heard about a new product - a condensing boiler? Yes, the information about him sounds very tempting: the efficiency is already above 100%, everything is beautiful and fabulous. What is the whole point? How was this achieved? Is everything true in his description or is there a drop of tar? We will answer these and other questions in our article. And now - a moment of attention!

Condensing boiler device

Internal organization condensing boiler

In order to understand this issue, let's start from the very beginning, namely, with the design of a condensing boiler. Let's look inside and find out what it consists of.

The most main feature this type of boilers - the presence of 2 heat exchangers. Otherwise, its design is similar to the design of a conventional gas device and includes:

Water inlet and outlet pipes- through them, cold liquid enters the equipment, heats up, and then through the outlet pipe it is fed to radiators and hot water supply.
Burner- responsible for the supply of gas to the combustion chamber, as well as for the uniform distribution of fuel.
Fan- is installed in front of the burner, and during operation it mixes particles of gas and air so that the resulting mixture burns well.
Heat exchanger No. 1- heats the water flowing through it to a predetermined temperature.
Heat exchanger no. 2- serves to condense moisture and extract heat energy from it. But more on that later.
Pump- to maintain water circulation.

Features of the condensing boiler

In order to better understand the ongoing process, let's take a closer look at principle of combustion and condensation.

What it is? It's simple: when hydrocarbon fuel burns, then as a result of the reaction, 2 substances are released: carbon dioxide CO 2 and water H 2 O. The resulting liquid, being in such a hot environment, almost immediately turns into steam. During the evaporation process, thermal energy, which, however, can be returned and sent additionally to our needs. And you can return it only if the steam is converted back into water.

The process of condensation and release of energy in this case has been known for a long time, but it could not be used in heating equipment. It's all about toxic condensate: during the combustion of gas, a lot of toxic caustic substances and formed carbon dioxide get into the combustion products. Such a vigorous composition very quickly caused corrosion of steel and cast iron heat exchangers.

Condensing units only became popular when rust-resistant steel alloys were invented.

That is why condensing boilers have special heat exchangers, which are made mainly of stainless steel or aluminum-silicon alloy (silumin).

The principle of operation of the condensing boiler

Condensing boiler: working principle

It all starts traditionally:

Water enters the device, gas begins to flow into the combustion chamber. There it is ignited by the ignition system.
During the combustion of fuel, combustion products are formed with high temperature. They pass through the first heat exchanger and heat its walls. And the walls, in turn, give off heat to the water circulating through the heat exchanger.
Further, these gases with a temperature above the dew point exit the heat exchanger No. 1 and enter the heat exchanger No. 2.
In heat exchanger No. 2, gases are cooled by means of water circulating through it from the heating system.
When their temperature equals the dew point temperature (at which condensate occurs), the released water vapor energy is transferred to the liquid that enters the heating equipment. And it was released during condensation.

Operating modes

The heat exchanger of condensing boilers has been specially designed in such a way as to extract energy from steam as efficiently as possible. The principle of operation of such a heat exchanger is also special: as we have already said, a heating return pipe is connected to it, through which water flows.

The lower the temperature of the water in this return, the more intense the condensation of moisture.. At the same time, the water temperature in this pipe should not be more than 50 ° C - otherwise the condensation process will not be possible, and the boiler will work like a conventional gas boiler, but still with less gas consumption - the benefit will be about 5%.

Therefore, we present the dependence of the efficiency on the water temperature in this reverse system.

If a liquid with a temperature of 40˚С flows in the direct water supply system, and 30˚С in the return one, then efficiency = 108%.
If the temperatures are 70˚С and 60˚С, then the efficiency will already be lower - 104%.
And at values of 90˚С and 75˚С, it will fall to 98%.

Features of condensate

As we have already said, the condensate that forms during operation has a very aggressive chemical environment. To collect it, the boiler design has a special container that needs to be emptied periodically.

How to be in that case? Of course, in foreign countries, such as Great Britain, Germany, special standards have been established, according to which such condensate is disposed of.

In Russia, there are no clear prohibitions and rules: condensate can be drained into the sewer without any negative consequences.

For example: for 1 day of operation of the boiler with a capacity of 25-30 kW, 25-28 liters of condensate are formed.

If this option disgusts you, then there is an alternative, some models are equipped with special condensate collectors. These containers are filled with magnesium or calcium granules. They absorb liquid, pass it through themselves, thus neutralizing its chemically active environment.

Gas outlet

All condensing models are equipment with combustion chamber closed type . There is no other option: an open chamber simply cannot support the combustion process. Due to the presence of the 2nd heat exchanger, which significantly complicates the process of movement of combustion products, and also due to the low temperature of the gases themselves (therefore, they will move very slowly), the air intake rate naturally will be small.

That's why for the removal of gases, a system of supply and discharge channel is used: it is logical to direct it through the wall / roof of the room, you can build smoke exhaust systems with your own hands.

Pros and cons of a condensing boiler

The list of advantages of this type of equipment is impressive and makes you think about purchasing it very seriously.

Compact dimensions and weight- they can be used even in houses and apartments with a small free area. In addition, you will significantly save on its transportation and installation.
economy- a completely logical plus, because the boiler design was created in such a way that less fuel was consumed to achieve the result. And so it is! Costs are less than traditional ones by 30-35%!
Precise modulation - in fact, this means a very careful choice of boiler power depending on external parameters (heat demand, air temperature in the room and outside the window, etc.). This also makes it possible to reduce fuel consumption if the boiler is partially loaded.
Low noise- it is also very pleasant, since the equipment can be placed next to living quarters, without fear that it will disturb the sleep of children, and indeed life in general.
Cascade function- an important aspect, especially if you need to heat a large house, or you will insure yourself in advance against a possible breakdown of the boiler. In this case, it can easily be replaced by another boiler from the cascade.
Reducing the selection of toxic substances into the atmosphere– a condensing boiler is about 70% more environmentally friendly than its traditional counterparts.
Low flue gas temperature- this is also a significant plus, since the low temperature of the combustion products allows you to install plastic chimneys. And their purchase and installation cost is much lower than similar work with classic steel chimneys.

Minuses. Of course, with such a rosy picture, you don’t want to spoil the impression, but still you have to talk about the essential. The point is their price - it is almost 2 times more than conventional heating models.

Of course, the boiler can pay off, but this is influenced by such factors as the intensity of use, temperature conditions etc.

Condensing boiler efficiency

Condensing boiler in the house

In order not to break the brain in vain, we will give an example of how they reached such a figure.

So, as we have already found out, a condensing boiler heats water from 2 types of heat: gas combustion and steam condensation.

Now let's turn to the very form of efficiency - what is it? Physics says: we will get the efficiency if we divide the value of the heat that was released by the heating batteries by the value of the heat that was released during the combustion of gas in the boiler chamber. Well, let's multiply everything by 100%.

Now let's turn to the concept fuel combustion points. Any fuel has 2 points of combustion: higher and inferior.

The high temperature is the sum of the low temperature + the condensing temperature.

Efficiency is determined precisely by the highest temperature.

Heat losses are present in absolutely any device: heat radiation into space during heating, heat loss through distant gases, etc. That is why the energy expended will never turn into heat. This is the reason why the efficiency will always be less than 100%.

However, there is a slightly different calculation system: lower heat 100% is absorbed by heat exchanger No. 1, and heat from condensation 8-11% by heat exchanger No. 2. So it turns out that the efficiency of condensation models according to this scheme is 108-110%.

Operation of the condensing boiler: video

If you have not yet fully figured out how this notorious condensing boiler still works, then we advise you to watch this video. It will bring some clarity:

The gas boiler was bought, the gas main was connected, the heating was installed, the most important thing remains - to assemble it all in single system. Connecting a gas boiler is not such an easy task, and it’s not even that the gas boiler is a high-tech equipment, and most importantly, dangerous equipment, the main problem lies elsewhere: too much various options and connection diagrams. The method, order of installation and connection of highways depends on individual conditions. Therefore, it is strongly recommended that the connection, start-up and adjustment of the gas boiler be carried out by an authorized Customer Service. Besides, independent connection boiler will void the manufacturer's warranty. But situations are different, so in this article we will tell you the main universal points for connecting gas boilers. And you will notice that the instructions for your boiler are of higher priority than any article on the Internet.

Gas boiler connection diagram

There are several schemes for connecting gas boilers. Which one to use depends on how the heating system is made - open or closed, the coolant in it moves by gravity or with the help of a pump, has one high-temperature radiator circuit or several circuits, among which there is a low-temperature "warm floor". Also of no small importance is the type of boiler - single-circuit or double-circuit, with open cam combustion or closed, convection or condensing.

Connection of a single-circuit gas boiler

Single-circuit boiler equipped with only one heat exchanger, which heats water for one circuit. Initially, such boilers were used exclusively for space heating, but today they can be successfully used for hot water supply by adding a boiler to the connection diagram. indirect heating. Single-circuit boilers are available in wall and floor versions, which one depends on the power generated. Single-circuit floor-standing boilers are more powerful and heavier than double-circuit ones, they can be used for heating a large country house and providing for households hot water.

The peculiarity of connecting a single-circuit boiler is that only two pipes with a coolant can be connected to it - one at a time it will enter the boiler for heating, and the other one will leave it heated.

In the embodiment presented above, the coolant will circulate through the heating system of the house and return to the boiler for reheating. Safety valve and expansion tank necessary to bleed excess pressure from the system.

This diagram shows the easiest way to connect to an indirect heating boiler - through a three-way valve.

Indirect heating boiler is a thermally insulated container in which there is water for sanitary needs. It is this water that we need to heat. To do this, a spiral heat exchanger is built inside the boiler, through which the hot water of the coolant passes.

In this scheme, heating water for hot water supply (hot water supply) is a priority. When a sensor is triggered on the boiler that the water has cooled down, a three-way valve is activated and all the coolant heated in the boiler rushes into the boiler. There he gives up his heat to the water and returns to the boiler for reheating. The boiler-boiler-boiler circulation will continue until the water inside the boiler is heated to the required temperature. After that, the three-way valve is activated, and the coolant from the boiler rushes into the heating system and will circulate according to the boiler-heating-boiler scheme until the water in the boiler cools down.

All the time while the water in the boiler is heating up, the coolant does not circulate through the heating system. How long it takes to heat up a boiler depends on its capacity. For example, a 200 l boiler (for big family), filled cold water, heats up for 6 hours. But the reheating of this boiler will take 40 - 50 minutes. Heating a boiler of a smaller volume, for example, 80 liters, takes only 10 - 20 minutes. This time does not significantly affect the overall temperature in the house, for such a short period it still does not have time to cool down.

Connecting a double-circuit gas boiler

It differs from a single-circuit one in that it has two heat exchangers: one is the main one, it heats water for heating, and the second is an additional one, it heats water for hot water supply. Most often, such boilers are a high-tech boiler room, in which everything is provided and automated, and are wall-mounted.

Pay attention to the photo, which shows the insides of a double-circuit boiler. 5 pipes are connected to it (from right to left): 1 - a pipe with a coolant from the heating system, which goes to reheating, 2 - a pipe with cold water, which goes to the heat exchanger to heat water for hot water supply, 3 - gas pipe, 4 - pipe with hot water for hot water supply, 5 - pipe with hot coolant for the heating system.

All automation of a double-circuit boiler is arranged inside. By default, the heat carrier heated in the boiler by the main burner is sent to the heating system and returned cooled back to the boiler. This is how the boiler-heating-boiler circulation occurs. But as soon as someone opens a hot water tap on one of the consumers, cold water begins to flow into the boiler through pipe 2. The three-way valve immediately redirects the coolant, and it does not go beyond the boiler, but the main heat exchanger circulates - an additional heat exchanger for heating water - the main heat exchanger. The heat carrier heats the hot water while it is in use. As soon as the valve is closed, the coolant begins to circulate through the heating system again.

As practice has shown, a double-circuit boiler is not able to provide a large amount of water for hot water supply, no more than one consumer - a kitchen or a shower, and then the water will not be too warm. The boiler simply will not have time to heat it in the proper volume. That is why they are used only in small families, and for heating water in more add a boiler to the system.

According to the presented scheme, the coolant will only heat the water in the boiler, and the water supply system to the second circuit will be closed. This trick allows you to significantly increase the durability of a double-circuit boiler, which suffers greatly from hard tap water. An additional heat exchanger for hot water becomes clogged and fails in about a year. That is why the circulation of pure coolant in the secondary circuit is more economical option. But then what's the point of using a double-circuit boiler if you can install a single-circuit boiler of greater power? It will be both more profitable and more practical.

Connecting a wall-mounted gas boiler paired with a conventional electric boiler as a storage tank for hot water also possible. In this case, hot water from the boiler will flow into the boiler, and when its amount decreases to a critical point (set automatically), the boiler will again heat water to fill the boiler. It is also possible that the boiler is filled with hot water from the boiler, and its further temperature is maintained using a heating element.

We have considered universal schemes for connecting gas boilers, now let's move on to the procedure for installing pipes and electrics.

Despite the fact that the diagrams above indicate where the inlet pipe is connected and where the outlet pipe is connected, be sure to read the instructions for your gas boiler. The location of the pipes may differ depending on the model and manufacturer.

First, a few words about the heating system itself. If it has already been used before, and now you are just changing the boiler, then it is necessary to drain the coolant from the system and be sure to rinse it several times. On the walls of pipes and radiators, a lot of various salts so that they do not clog the fragile heat exchanger of the boiler, it is better not to be lazy and flush the system.

In the heating system can circulate as water, and antifreeze. Is it possible to use antifreeze specifically with your boiler, be sure to look at technical documentation. Sometimes boiler manufacturers themselves recommend certain brands of antifreeze or even produce it themselves. It is not worth neglecting such recommendations.

It makes sense to use antifreeze as a coolant in the heating system only if you live in the house on short visits and turn off the boiler when you leave for a long time. The water in the pipes in this case may freeze, but the antifreeze does not. But if you live in the house all the time and do not turn off the boiler in cold weather, then it makes sense to use water as a coolant. The reason for this is the disadvantages of antifreeze: low heat capacity, high viscosity and coefficient of thermal expansion. For the entire system, this threatens that with antifreeze it is necessary to use a boiler and pumps of greater power, storage tank larger capacity and larger heating radiators.

In favor of the use of water is also evidenced by the fact that modern gas boilers can be put into safety mode, when the coolant cools down to +5 ° C, the boiler heats it up again.

The scheme for connecting heating to the boiler is as follows:

Circulation pump (if required).
Ball valve.
Coarse filter.
Ball valve.

Circulation pump always installed on the "reverse". Ball Valves necessary in order to easily disconnect the system from the boiler without draining the coolant, as well as quickly remove the filter for prevention and cleaning. Coarse filter in the heating system, it is necessary in order to protect the boiler heat exchanger from clogging with salts, it is placed directly in front of the boiler, preferably on a horizontal section with a sump / catcher down. If it is not possible to install the filter on a horizontal section of the pipe, then install it on a vertical one. The direction of the coolant flow must necessarily coincide with the direction of the arrow on the filter housing.

The pipe with the hot coolant coming from the boiler must be connected to the boiler branch pipe using an American quick coupling and a shut-off ball valve must also be installed.

It is necessary to install ball valves on the inlet and outlet pipes with the coolant to drain the coolant from the system to summer period or for repairs.

Scheme for connecting hot water to a double-circuit boiler:

Coarse filter.
Ball valve.
Fine filter or magnetic filter.
Ball valve.
Quick coupling "American".

In order to maximize the service life of the additional heat exchanger of a double-circuit boiler and protect it from scale, it is necessary to install on the supply pipe with cold water coarse filters and magnetic filter. If the coarse filter has already been installed before the water meter, then it does not make sense to install it in front of the boiler.

The hot water outlet pipe must be connected to the socket with ball valve with "American", it is desirable to install a check valve.

All connections must be sealed with tow or FUM tape, and even better with special plumbing paste.

Modern gas boilers come with two options for connecting to the mains - a cable with a plug for connecting to a socket and a three-core insulated cable. Whatever option you come across, in any case, you should follow this rule: the gas boiler is connected through an individual circuit breaker directly to the shield and it is imperative to take care of grounding. It is also advisable to use voltage stabilizers or backup sources power supply in the event of a power outage.

Automatic shutdown is installed near the boiler so that it can be easily and quickly turned off. Even if the boiler has its own cable with a plug, it is necessary to make a personal socket for it, to which power is supplied through the circuit breaker.

ground the boiler on the gas pipeline or heating pipe is not allowed. To ensure high-quality grounding, it is necessary to equip either a ground loop or point grounding. For the latter, there are ready-made universal kits modular grounding (ZZ-000-015), the installation of which will take an area of 0.5x0.5 m in the basement of the house, underground or on the street next to the house. The resistance of the ground loop for the heating boiler must be no more than 10 ohms. In different sources you can find other figures, but gas services require just such indicators - no more than 10 ohms. This is necessary for safety net and is due to the fact that power poles overhead lines for the most part do not have re-grounding.

Gas boilers are different - some need a regular chimney, others need a coaxial chimney, and others (parapet boilers) do not need it at all. Therefore, read the instructions for your boiler. Moreover, most often, a chimney is already included with a gas boiler, it only needs to be properly installed.

Rule one - the diameter of the boiler chimney must be equal to or greater than the diameter of the outlet pipe in the boiler.

Most often, the diameter of the chimney depends on the power:

up to 24 kW - 120 mm.
30 kW - 130 mm.
40 kW - 170 mm.
60 kW - 190 mm.
80 kW - 220 mm.
100 kW - 230 mm.

Ordinary chimneys are brought up, 0.5 m above the ridge of the house. They can be arranged both inside the wall of the house, and inside the house itself or behind its wall. No more than three bends per pipe are allowed. The first section of the pipe connecting the boiler to the main chimney must be no more than 25 cm. The pipe must have a closing hole for revision cleaning. For boilers with conventional chimneys and an open combustion chamber, a large air supply is required, it can be provided either with an open window or a separate supply pipe.

Rule two - the chimney must be made of sheet metal or other acid-resistant material. The same applies to short sections, swivel elbows and other things. Do not connect the boiler to the main chimney with a corrugation, do not use brick chimney. As a result of gas combustion, steam is formed, saturated with sulfuric and other acids, in the process of condensation, acids precipitate and corrode the walls of the chimney.

Rule three - the coaxial chimney is mounted horizontally and led directly into the wall. This type of chimney is a pipe in a pipe. By inner tube vapors are removed from the boiler, and air enters the combustion chamber through the outer one. This allows you to heat the air and increase the efficiency of the boiler.

The coaxial chimney should move away from the wall of the house by at least 0.5 m. If the boiler is ordinary, then the chimney pipe should have a slight slope towards the street. If the boiler is condensing, then the slope should be towards the boiler - then the condensate will drain into a special tube - a siphon, which must be drained into the sewer. Usually in condensing boilers everything is written in the instructions. Maximum length coaxial chimney 3 - 5 m, the more turns or bends, the smaller the allowable length.

Rule four - the parapet gas boiler is installed strictly according to the scheme near the outer wall. The coaxial deflector is most often located at the back of the boiler, and not at the top.

A gas boiler usually comes with all the necessary decorative wall linings, clamps and other elements.

Connecting the boiler to a gas boiler

As mentioned above, the boiler is connected to a gas boiler to provide hot water. It can be connected to both a single-circuit boiler and a double-circuit one. There are several connection schemes and those proposed below are only the most common.

This scheme has already been described above. A three-way valve is installed on the heating supply line, a pipe goes from it to the indirect heating boiler itself, where it is connected to the pipe with the help of an "American". The pipe with the cooled coolant from the boiler crashes into the line with the "return" heating. For ease of use of the boiler, the outlet pipe must also be connected to the American pipe.

If the safety group, pump and expansion tank are located directly in the boiler, such as in wall boilers, then the three-way valve is controlled by the boiler itself, to which the signal comes from the boiler thermostat (needs to be connected).

If the boiler is floor-standing, then you can connect the thermostat directly to three-way valve, then the control will occur directly.

Boiler connection via additional pump

This connection scheme also assumes DHW priority. It uses two pumps: one for the heating system, the other for the boiler circuit.

This scheme is used if the system has several circuits, for example, 1 circuit - radiator heating, 2 - circuit of the "warm floor" system, 3 - circuit of the boiler for hot water supply. The hydraulic arrow and distribution manifolds allow you to evenly redistribute the coolant between the circuits. You can learn more about the operation of the hydraulic arrow from the video.

In addition to the proposed schemes, there are others - you can make the DHW circuit circulate through the system so that hot water always flows from the tap and you do not have to drain cold water from pipes. You can also use not just an indirect heating boiler, but a boiler with a built-in heating element for reheating hot water and many other tricks that are best checked with a specialist.

Connecting a thermostat to a gas boiler

connected to a gas boiler in order to provide more economical work. A thermostat is installed in the most remote room or in a place where you would like to navigate, is it time to “turn up the heat” or is it still warm. This device will send information to the boiler automation that the temperature in the room has reached the lower allowable mark, the boiler will automatically turn on and heat the coolant until the thermostat reports that the maximum temperature has been reached.

The thermostat must be positioned at inner wall at home, 150 cm above the floor. The device must not be exposed to various heat sources, vibrations, drafts and sunlight.

In modern boilers for connection room thermostat special terminals are provided. Initially, the contacts are closed, as if giving a signal to the boiler that it is necessary to heat the coolant. Therefore, this contact-closing jumper must be removed. Then connect the thermostat to the terminals with a two-wire cable 0.75 mm2.

The gas service must connect the gas to the gas boiler and start the boiler, otherwise you will have to pay an impressive fine for arbitrariness. For reference, we clarify that it is necessary to supply gas steel pipe or corrugated pipe from stainless steel with a diameter of 8 - 9 mm, also use a paranitic gasket and tow for sealing. It is impossible to use rubber hoses in a metal braid, FUM tape, plumbing paste, etc.

It's time to consider and deal with the features of condensing gas boilers ...

Condensing gas boilers: principle of operation, types and advantages

Thanks to their high-tech design, condensing boilers make the heating system much more convenient, comfortable, and economical. If in conventional devices the products of combustion give only a part of the thermal energy, then in this case it is done to the maximum. The Luch Tepla company presents boilers of all types in a large assortment.

Design

By their structure, condensing boilers are indistinguishable from typical heating appliances. Available in several versions:

wall-mounted (more traditional, focused on individual heating systems of private residential buildings);
floor (increased power, designed for use in office and industrial premises).

Their design includes a non-standard heat exchanger made on the basis of acid-resistant materials. Usually - from steel-stainless steel or silumin. It looks like a pipe with a complex section and spiral fins. All this increases the heat exchange area and makes the gas boiler more efficient.

Besides, condensation device equipped with a fan placed in front of the burner. It "sucks" the gas from the gas pipeline, mixes it with air and directs it directly to the burner. The boiler also has an electronically controlled pump, which allows you to optimize the heating power, reduce noise from the coolant passing through the system and save on electricity.

Types of Condensing Gas Boilers :

Condensing boilers are of several types:

single-circuit;
double-circuit;
heating;
water heating.

At the same time, their power can vary from 20 kW to 100 kW, which is quite enough for domestic boilers. For office and industrial premises, they are produced with greater power and in the floor version.

Operating principle of condensing gas boilers :

In standard boilers, the hot exhaust gases are simply vented to the atmosphere through chimney channel, losing a significant share of unused heat. It is discharged to the outside along with the waste products in the form of water vapor, which is formed at the time of fuel combustion. It is in the steam that the additional thermal energy lies, which the condensing boilers store and then transfer to the heating system.

Cooling, the vapor condenses, that is, it becomes a liquid, and releases a certain amount of heat. This process takes place in a special heat exchanger with an expanded area. It is he who “takes away” heat for transfer to the heating system. This approach has been known before. But it began to be used relatively recently due to the emergence of corrosion-resistant alloys, which form the basis for the production of condensing boilers.

Features of operation of CONDENSING gas boilers:

The efficiency of such gas devices largely depends on the characteristics heating system. The lower the water temperature, the more complete the process of condensation of water vapor. Therefore, the higher the amount of latent heat that is returned to the system.

In this way, the condensation mode is maintained throughout the entire heating period. That's why essential condition for the functioning of the condensing boiler is the average temperature of the coolant. For example, at the entrance to the boiler, it should be less than 60 degrees (ideally, up to 57 degrees). This will give better condensation and increase the efficiency of the heating device.

But even if you combine a condensing boiler with old system, it will still bring tangible savings, as it will be more efficient than the old equipment. This is due to the fact that in our climatic zone the most frosty days in total occupy a little more than 10 percent of the duration of the entire heating period. On other days optimal condensation is possible.

Advantages

Among the basic advantages of this type of boilers is high efficiency. In this case, it is equal to 108-109 percent, when compared with other boilers. Another advantage is their increased economy. It is approximately 15-20 percent more than standard heating appliances.

To understand how profitable condensing heating boilers are in use, it is necessary first of all to consider their principle of operation. One of the features in this case is the receipt of additional heat, which is the result of the condensation of combustion products. This phenomenon occurs due to a decrease in temperatures in the combustion chamber to 100-110 degrees, which cannot occur in a conventional chimney due to a strong decrease in thrust.

Therefore, to achieve the maximum use of fuel energy, you should connect the work of hidden resources. Latent heat is that part of it that is brought out along with water vapor and smoke. Such heat losses may seem insignificant, but in fact, their preservation can significantly increase the efficiency of the heating structure.

The efficiency of a condensing boiler is higher due to the fact that, compared to a conventional design unit, it condenses the steam released during combustion. Further, this steam is mixed with smoke, and the energy released in this case is directed to ensure additional heating of the coolant.

Important! In order for condensation to occur, it is necessary to provide a temperature difference between the vapor and the surface with which it is in contact. Thus, cooling, the vapor passes into a liquid state, reaching the dew point. To provide efficient process condensation, it is necessary to ensure that the temperature drops to 60 degrees Celsius.

Design features

The operation of a conventional gas boiler is as follows: when the fuel is burned, the coolant is heated and the combustion products are released into the atmosphere through the chimney. Any unit long burning in practice proves the low efficiency of such a scheme. Therefore, to increase efficiency, there are several significant changes in the design of condensing-type units:

For effective cooling of smoke, another chamber is provided in the design. It is fed into it after the fuel burns out in the furnace.
Adjustment of the intensity of the flame thanks to the installed modular burner.
The system has an additional heat exchanger, thanks to which water is circulated from the return pipe. The temperature difference contributes to the condensation of steam, in which heat is actively released, heating the coolant.
Removal of the cooled smoke is carried out by means of an external contour of a coaxial cable. The system also has an internal circuit used to supply oxygen.
Condensate is collected in a specially designed container.
A fan is installed in front of the burner, due to which the gas is better saturated with oxygen.

The principle of operation of such boilers on video

Advice! In order to save money, the chimney for such a boiler can be made of plastic. Since, due to the design features, the temperature of the exhaust air does not exceed 40 degrees, then plastic pipe will do the job perfectly.

Advantages and disadvantages

Now let's take a closer look at the pros and cons of condensing boilers. The design has several obvious advantages:

Both floor-standing and wall-mounted condensing gas boilers have more high power compared to conventional units.
Substantial fuel savings, achievable due to the original design of the burner. Thanks to it, it is possible to accurately regulate the operation of the unit.
The minimum amount of harmful emissions into the atmosphere.
Heat loss in the volume of not more than 2% of the total heat.
High compactness. Even a floor condenser will be significantly more compact than its counterpart of a traditional design.
A double-circuit boiler of this type is great for houses with a "warm floor" system.

Durability due to the high quality of the materials used and the competent setting of the operating mode.

Important! Such units are most effective when used in houses whose area exceeds 200 m2. In this case, there is a large difference in return and supply temperatures, and the efficiency of the device increases significantly when the low-temperature return branch of the coolant is heated. In addition, the larger the heated area, the more obvious the savings when using such equipment.

The disadvantages of this type of boilers include the following:

A sealed chimney equipped with forced ventilation is required.
A high level of efficiency is achievable only in low-temperature heating systems.
Energy dependence.
High cost compared to traditional designs.

Mounting Features

Installing a condensing unit involves several important nuances. And the first one is the choice of location. The best option in this case, a specially designated room will become, but if it is not there, then installation can be carried out in the kitchen.

Advice! The walls of the room in which the unit will be installed must be tiled. The floor must also be non-combustible. There must be an exhaust hood in the room.

Hinged structures are fixed on the wall using dowels. Correct location the boiler is achieved if its lower part has a slightly greater indentation from the wall than the upper one.

Chimney installation features

Today, there are a number of options for connecting a chimney to a heating boiler. But whichever of them is chosen in the end, it is important to maintain high tightness. The design of chimneys for condensing units does not differ significantly from the chimney connection schemes in traditional models.

The main requirements are as follows:

Production material. Chimney such a unit must be made of plastic or stainless steel. The main parameter here is not resistance to elevated temperature, and acid resistance. The fact is that condensate has the same effect as light acid, therefore it is very important that the material is not afraid of corrosion.

Chimney angle must be such that condensate can flow back into the boiler, but precipitation must not enter it, as this may result in damage to the unit due to a short circuit.

How to organize the correct condensate drainage and avoid installation errors

As mentioned above, the basis for the operation of condensing boilers is the formation of condensate.

Important! The amount of condensate formed directly depends on the power of the equipment. So, during the day, the unit can accumulate up to 50 liters of condensate, which has a low acidity. Therefore, this liquid can be drained directly into the siphon of household waste, which will not cause any harm to the environment.

Consider the main mistakes that can be made when installing such equipment:

One of the most serious mistakes is the lack of a tank in the system designed to drain condensate, or its size is not suitable. Unfortunately, given error allowed even by experienced professionals.
The wall-mounted boiler is installed on a wall that has a coating that is not protected from fire. This may cause a fire.
The condensate is discharged outside. This is unacceptable, since at sub-zero temperatures, icing of the tube is possible. As a result, the unit may simply lock up and fail.
Lack of gas filters in the system.
The boiler is equipped gas meter, which does not match its power.
During installation, the correct slope of the equipment is not observed.

When installing, be sure to take into account all the above points. Only in this case, the installed unit will function correctly for a long time.

The most popular manufacturers

On the modern market heating appliances there is a number of condensing units manufactured by various companies. Consider the most popular manufacturers whose products have proven themselves due to high performance and uninterrupted operation:

Wisman ( Viessmann). The company is one of the world leaders in heating and refrigeration systems. Its products are distinguished by the introduction of new technologies and high performance. Wiesmann is doing an excellent warranty service its technology and carefully cares about the quality of products. True Italian quality at relatively affordable prices.
Vaillant ( Vaillant) - German manufacturer heating equipment, which has gained significant popularity in more than 60 countries around the world. High quality Vaillant products are emphasized by their compliance with international standards. The company annually invests a lot of money in the modernization of its technologies, producing premium-class equipment.

Baksi ( Baxi). Another Italian company specializing in the production of heating equipment. It is one of the European leaders, having been present on the market for more than a decade. Big the lineup and high reliability of the equipment produced by the company - distinctive features this manufacturer.
Buderus (buderus). Well-known German company, which is one of the oldest in Germany. It has been manufacturing heating equipment and accessories for almost 300 years. Today it is one of the undisputed leaders in the world market.

Conclusion

Condensing boilers are an excellent option for home heating. This is a reliable and productive equipment with high efficiency and enviable economy. Best of all, such units are suitable for heating private houses of a large area, since in this case the level of efficiency increases significantly.