Gas wall-mounted boilers of low power. The smallest gas boilers. The best wall-mounted gas boilers

Fondital Antea CTFS 24

One of the smallest mounted gas boilers is Fondital Antea CTFS 24. Its height is 700 mm, width is 400 mm, depth is 250 mm. It has a weight of 26 kg.

This double-circuit model with a closed combustion chamber has a power of 25.5 kW, which is enough to heat 220 m². The boiler is equipped with two separate heat exchangers: the primary is made of copper, the second is made of steel. It has a modern control board and a user-friendly user interface.

Main characteristics of Fondital Antea CTFS 24:

• Efficiency=93%;
• gas consumption - up to 2.7 m³ / hour;
• DHW capacity at Δt=30 - 11.1 l/min;
• country of origin - Italy.

Ferroli FER EASYtech C 24

Model Ferroli FER EASYtech C 24 has the following dimensions: height - 700 mm, width - 400 mm, depth - 230 mm. The weight of the boiler is 27 kg.

This double-circuit unit with an open combustion chamber has a power of 24 kW and is able to heat a room up to 200 m². It is equipped with an enlarged bithermic heat exchanger and modern multifunctional control and monitoring systems for safe operation. The type of combustion chamber requires the installation of a classic chimney.

Key features Ferroli FER EASYtech C 24:

• Efficiency=90.5%;
• DHW capacity at Δt=30 - 11.1 l/min;
• country of origin - Italy.

TERMET MiniMax DYNAMIC 24 kW (turbo)

The compact boiler TERMET MiniMax DYNAMIC 24 kW (turbo) has a height of 700 mm, a width of 360 mm and a depth of 300 mm. Weight is 28 kg.

This double-circuit unit with an open combustion chamber has a power of 24 kW and is able to heat an area of ​​​​up to 200 m². The primary heat exchanger is made of copper, the secondary heat exchanger is made of stainless steel. The boiler is equipped with a modulating burner and necessary systems control over safe work. The type of combustion chamber requires the installation of a classic chimney. Main characteristics of TERMET MiniMax DYNAMIC 24 kW (turbo):

• Efficiency=91%;
• DHW capacity at Δt=30 - 11.4 l/min;
• gas consumption - up to 2.7 m³ / hour;
• country of origin - Poland.

Gas boiler for heating a private house is not only a necessity, but one of the main elements comfortable living, therefore, the choice must be approached consciously at the stage of designing the entire system as a whole. Market heating equipment does not stand still and is constantly developing and the result of fierce competition is the presence of the widest choice of boilers of various brands, configurations and modifications. Unlike owners of city apartments, who most often receive a boiler after the fact, the owner of a private house has the opportunity to choose a unit at almost any stage of designing his house.

From the author: the purpose of this article is to get acquainted with modern heating technology, its main differences, variety and applicability. We are not representatives of any of the boiler manufacturers, but we are engaged in diagnostics and repair of electronics of gas units and we will try to make this review as practical and not biased as possible.

Criteria for choosing a gas boiler

One of the main selection criteria gas boiler is the required power and the need for hot water at home. Ideally, the required power of the boiler is selected based on the thermal calculation of the building that will be heated by it. In the process of thermal calculation are taken into account heat loss rooms, number of windows, doorways, ceiling height, wall materials and characteristics of the selected thermal insulation.

There is an opinion that it is possible to select the power of the unit at the rate of 1 kW per 10 square meters area, but this value is rather arbitrary. Modern thermal insulation materials, plastic windows and insulated doors significantly increase the energy efficiency class of buildings, and this figure can be reduced by 20-30%.

A strong overestimation of the boiler power can lead to a decrease in its efficiency. Modern gas boilers allow you to adjust the power in a fairly wide range, but it should be borne in mind that the maximum efficiency and economy of the boiler will be achieved when it operates at rated power. Continuous operation of the boiler

the lower limit of power reduces the efficiency of the unit by about 12-15%. Information on the value of efficiency in different modes of operation, as a rule, is indicated in the passport or instructions for the device. Overstating the power of the boiler is also fraught with too frequent switching on and off of the device, which negatively affects executive mechanisms and electronics.

When choosing power, some experts recommend taking into account the need for hot water preparation and increasing the power by 20%, or even twice. Naturally, when choosing a gas boiler for heating a private house, it is assumed that residents will also need hot water, but it will be more correct to be guided not by power, but by the number of hot water points and their distance from the boiler room.

Often the final power and type of boiler is selected based on the needs for hot water preparation.

Depending on this criterion, there may be several options:

double-circuit gas boiler

boiler with built-in boiler

single-circuit boiler and boiler indirect heating

Double-circuit gas boiler

Double-circuit gas boilers are designed to heat the coolant in the heating system and, if necessary, prepare hot water, i.e. they have two independent circuits. Depending on the type of boiler, double-circuit models can be with one heat exchanger (primary) and with two additional plate heat exchangers for preparing hot water. When choosing such a boiler, you should pay attention to the performance of the boiler in hot water mode. On average, the water consumption of one point of water parsing at a comfortable pressure and average pressure will be about 8-10 liters per minute.

Based on this, for example, a 24 kW double-circuit boiler will be able to provide approximately 2 points of water analysis, because the performance of the heat exchanger in DHW mode in most cases will be 14-15 liters per minute. And such productivity will be at a temperature delta of 25 degrees, at a temperature delta of 35 degrees this value will be significantly less - in the region of 10 liters per minute. Delta is the temperature difference cold water and desired heating temperature. Comfort temperature DHW is about 40 degrees, therefore, at an incoming cold water temperature of about 5 degrees (in winter period) - the delta will just be 35. For example, we present these characteristics for some of the most famous models:

With an increase in the power of the boiler, these figures will not increase significantly. For 32-36 kW models, this is approximately 15-16 l / min, and for 38-40 kW, 18-19 l / min. Therefore, it is obvious that a double-circuit boiler with a secondary heat exchanger can be considered mainly for small private houses or apartments up to 120 square meters with two, maximum three points of water analysis. Double-circuit boilers are separate devices and are not designed to work together with boilers.

Summing up, we can distinguish the following features of dual-circuit models:

versatility (both heating and hot water at the same time)

dimensions (can be mounted in a kitchen cabinet)

ease of installation and operation

lower value (cost) of initial costs

Boiler with built-in small volume boiler

Such boilers have some advantages compared to typical double-circuit boilers: instead of a flow-through heat exchanger, a small boiler capacity is installed (usually 40-60 liters) and this means that there is always a small supply of hot water. Firstly, residents practically do not need to wait for the initial water heating. Secondly, the boiler will turn on less often - it happens that it is necessary to briefly open the tap to rinse the cup. The double-circuit boiler in this case will turn on and will heat the water at full power, the option with a built-in boiler will turn on only when the temperature of the spare water drops below the set one. Fewer start-ups - longer service life of actuators.

For example: the Ariston CLAS B EVO 24 FF model (built-in tank of 40 liters) already has a DHW capacity of 16 liters per minute at a delta of 35 degrees and 19 liters per minute at a delta of 30 degrees 10 minutes after switching on!

Obviously, such boilers have a greater degree of comfort, but are significantly more expensive. Also, they are free from the problem of scale formation, that is, they are less demanding on water quality. When choosing a boiler for a private house, you should pay attention to the performance in hot water mode and ease of maintenance.

Single-circuit boiler and indirect heating boiler

An indirect heating boiler is a water storage tank that does not have its own heating element, and is heated by external sources (for example, a boiler or solar panels). According to many experts, the use of a single-circuit boiler and a boiler in the heating circuit is most preferable. From the previous version, such a scheme differs in the volume of the boiler itself in the direction of increase. The boiler is selected based on the needs of the residents of a private house in hot water. There are various methods, calculators is a topic for a separate review. Individually, it is necessary to determine the maximum possible one-time water consumption, for example, in the morning hours, and select a container of the required volume. The performance of the boiler will depend on the capacity of the boiler, because the capacity of the boiler itself is limited by the capacity of its coil. The volume of the boiler is selected from the peak values ​​​​of water consumption. If averaged, the following recommendations can be made: up to 80 liters for a family of 1-2 people, up to 150 liters for a family of 3-4 people, and from 200 liters for families of more than 5 people. In non-standard cases, it is necessary to carry out design calculations.

Thus, we get the following advantages of using a boiler:

constant supply of hot water ( maximum comfort)

lower hydraulic resistance compared to plate heat exchanger

reduction in the number of boiler starts

reduced water consumption (no need to drain water while waiting for heating)

no scale formation (does not cancel regular maintenance)

Some manufacturers of heating equipment have ready-made boiler + boiler options that are installed in a single system.

So, in the end - we select the boiler according to the heat losses of the house, the boiler - according to the needs for the amount of hot water.

In addition to the main operational characteristics, boilers have a number of other differences: the material of manufacture and the type of heat exchanger, the type of combustion chamber, and the method of installation.

According to the installation method, floor and wall boilers are distinguished. Wall-mounted boilers are distinguished by their compact size, light weight and versatility, they are used when there is no separate room for installing a gas boiler. Floor models are equipped with cast iron heat exchangers (therefore, they are heavy) and require certain requirements from the room during installation. Distinctive feature of such boilers is their high reliability. Cast iron heat exchanger It has high corrosion resistance and long service life. Among the shortcomings - fragility and heavy weight.

Heat exchangers of wall-mounted boilers can be made of steel, copper, aluminum alloy or stainless steel. Steel heat exchangers are the cheapest and have a number of disadvantages, such as lower efficiency, a tendency to deformation and have a shorter service life. Copper heat exchangers have significantly higher thermal conductivity, corrosion resistance and lighter weight.

Bithermic heat exchanger

Worth considering separately design feature gas boilers with bithermic heat exchanger. In “bithermics”, heating of the heating coolant and running water takes place in a single primary bithermic heat exchanger (there is no secondary one). When the boiler needs to heat the heating system, the circulation pump turns on; when DHW heating is required, the pump turns off and all power is transferred to the tap water flowing there. The heat exchanger itself is a pipe-in-pipe design (one is heating, the other is hot water). The advantage is low cost, but an important necessity is the water treatment of the water passing through the heat exchanger. Limescale, which actively forms on the walls at high operating temperatures, can significantly reduce the service life.

Atmospheric and turbocharged gas boilers

According to the method of removing combustion products, gas boilers are divided into atmospheric, where smoke is removed from the combustion chamber due to natural draft in the chimney, and turbocharged, in which combustion products are removed forcibly by means of a fan.

Gas boilers with a fan are more expensive, but more economical and have higher efficiency. To install such a boiler, a classic chimney device is not required, it is enough to use coaxial chimney(pipe in pipe), in which air is supplied and removed through one common pipe, which can be taken out of the room through the wall.

Modern fans with variable speed allow you to achieve significant savings and, in combination with a modulated gas burner adjust the power of the boiler in a very wide range, as well as obtain high efficiency in low power modes.

Condensing boilers

All roughly represent the process of heat transfer in a conventional gas boiler: the heat exchanger is located directly above the burner and when the gas is burned, heat is transferred to the coolant. During the combustion of the gas-air mixture, the formation of carbon dioxide, water and heat is released. The rest of the heat that the heat exchanger did not have time to accept goes into the chimney, while the temperature of the flue gases can be from 140 to 170 degrees.

With such a scheme a large number of The heat just escapes into the chimney. This is due to the fact that the combustion products contain approximately 10% of water in the gaseous state, i.e. in the form of steam and manufacturers are trying in every possible way to avoid the condensation of this steam inside the boiler or chimney. The layout of a traditional boiler is designed to prevent the formation of condensate, because condensate is water only in a simplified form. In reality, combustion products contain harmful impurities, which form an aggressive mixture of acids (nitric, sulfuric, coal), which lead to rapid wear of the boiler elements.

The process of condensate formation begins when the combustion products are cooled to about 55-57 degrees. Therefore, the solution for extracting additional heat is to cool the combustion products to the conditions for the formation of condensate inside the boiler and control this process. For maximum heat transfer to the heat carrier, a large area of ​​​​the heat exchanger and the creation of conditions for the formation of condensate inside this heat exchanger are required. In addition, the condensate, cooling down, gives additional heat, which, in fact, is transferred to the coolant, flowing down the walls. That is why marketers often indicate the efficiency of such boilers as more than 100%, adding to the efficiency of a traditional boiler the effect of heat transfer by condensate.

Example: Baxi LUNA DUO-TEC 1.24 GA. Maximum power 24.7 kW, and minimum power only 3.7 kW!!!

In addition to the efficiency of heat removal, condensing boilers can regulate power over a very wide range. This is especially true in the middle lane, where the average annual temperature ranges from 0 to 5 degrees. Therefore, such a boiler will be much more economical than the traditional one in the off-season, when the nominal power of the boiler is not required.

In addition to all the advantages, it is worth noting that in order to obtain the maximum capabilities of a condensing boiler, low temperature regime work (supply temperature less than 50 degrees), and this is not always possible. Since the boiler, in fact, is additionally a condensate generator, it must also be disposed of in a country house using septic tanks - this will have to be taken care of additionally.

In a country house, insects can also become a real problem for such a boiler. The temperature of the exhaust gases is low and therefore attracts insects, and in the case of a coaxial chimney, and x will be continuously sucked into the combustion chamber.

Conclusion

In this review, we have analyzed the main differences gas installations presented on the market, considered typical schemes applicability. Choosing a gas boiler can be a difficult task, which one to choose - Ariston, BAXI, Vaillant or Protherm? Let's give some advice.

Choose boilers of popular brands, widely distributed in the market of a particular region. The purchase of products from little-known manufacturers can lead to a limitation of the life of the boiler until the first breakdown.

Pay attention to the materials and manufacturers of the main components of the boiler (hydraulic group, circulation pump, heat exchanger). Preference should be given to well-known world brands and durable manufacturing materials.

Expansion tank. It is worth looking at whether the volume of the built-in expansion tank will be sufficient for your conditions, because in different boilers of the same power it can differ in the range from 6 to 10 liters. If the heating system provides its own expansion tank, then the recommendation can be neglected.

Be sure to evaluate the cost of boiler ownership and availability service department and spare parts. You can compare prices for the main components: heat exchanger, electronic board, fan and others. In different regions, the availability of spare parts may be different, so you should give preference to the most common brands, with which in the event of a breakdown, for example, during the heating season, there will be no problems.

When choosing, compare technical equipment different models: the presence of self-diagnosis, anti-freeze, post-circulation functions, power adjustment ranges, the presence of a warm floor mode (if necessary) and the ability to connect programming options and weather-dependent automation.

In the case of choosing a single-circuit boiler for antifreeze as a coolant, specify the possibility of its use. Some manufacturers prohibit the use of antifreeze in their boilers.

Be sure to read the terms of the product warranty. In some cases, the warranty can be calculated from the date of manufacture of the product and if you are sold a boiler that has been in storage for two years, you will lose the lion's share of the warranty period.

As for the reviews, we do not recommend using them as the ultimate truth. The history of equipment operation may be different and depend on specific conditions, region, water hardness, power quality, literacy of the designer and installer. Some people take care of things, observe intervals Maintenance and operating rules, others believe that you can not approach the boiler for 10 years and everything should work. On the Internet, you can often find overtly custom reviews or reviews written for search engines, so they are often biased and carry absolutely no value. A gas boiler has long been no longer a luxury and is used everywhere, therefore, it is better to take advantage of the reviews of the owners, who are likely to be found in the immediate vicinity.

We hope that this material will help you in choosing a gas boiler for heating a private house, we also recommend watching a video with recommendations from professionals.