Gas boilers for the heating of a country house permanent favorites of Russians. We tell some of the modern models better prefer: convection or condensing.
Photo: shutterstock / fotodom.ru
A feature of the condensation boilers "Lynx" (protherm) is a cast heat exchanger from aluminum and silicon alloy. His design makes the boiler less sensitive to water of poor quality. Photo: Vaillant.
It is believed that the service life of expensive floor boilers with a massive cast iron heat exchanger is 25-30 years. Most modern models (both outdoor and wall-mounted installation) is less than 8-10 years. But the cost of such devices is significantly lower. Thanks to this, devices remain available for most of the population. Thus, the most inexpensive CIS boilers can be purchased, for example, for 10-15 thousand rubles. True, it will, as a rule, the models are not very perfect from a technical point of view - bulky (almost everything for floor installation), not fully automated. But they are quite suitable for the replacement of old domestic floor boilers of type AGB 120, and therefore they have steady demand.
The package of two-circuit boilers GAS COMI Boiler (NAVIEN) includes a remote control panel (b). Photo: Boris Bezel / Burda Media
However, over the past two decades, many houses have appeared equipped with newer and perfect gas boilers. This is mostly wall-mounted models. They are equipped with burners and heat exchangers of improved design, which allow to develop power sufficient for heating of 150-200 m² mansions, which previously thought it was possible to dump solely with the help of floor mounting boilers.
More than half of these boilers are double-circuit, adapted not only for heating, but also for the preparation of hot water for the DHW system. Now a two-round wall-mounted mounted boiler manufacturers (Ariston, Baxi, Bosch, Buderus, Kiturami, Protherm) can be purchased for 30-40 thousand rubles, and the choice will be wide enough.
Photo: shutterstock / fotodom.ru
When you need power
Wall condensation boilers Buderus Logamax Plus GB172i are distinguished by an improved design of heat exchangers, efficiency and original design. Photo: Bosch.
In the first models of condensation boilers, they were distributed in Russia not even due to efficiency, and because of high power. Only these wall-mounted models provided performance up to 60-90 kW. In the conditions of a large house and a small room of a boiler room (or even its absence), only such boilers ensured the production of the necessary amount of heat and hot water.
How many contours do you need?
Quite often, people choose a double-circuit boiler, believing that only such a device is optimally coping with heating, and with hot water supply at home. It is not quite so, sometimes a single-connecting boiler is even more preferable. For example, if you have a big family and four or five point of water intake. In this case, the best solution will be the purchase of a boiler and a separate boiler, since the two-circuit model may not cope with intensive load. But if you have a family of two or three people and one or two points of the waterborne, the two-kilt boiler will be quite enough.Condensation boilers
Wall-mounted convection gas boiler Vaillant Turbofit. The heat capacity of the boiler is stable at a gas pressure from 13 to 20 mbar. Photo: Vaillant.
What is new to us manufacturers? Probably the topic number one is the notorious condensation boilers. Such equipment is now produced by all leading manufacturers and is very popular in Europe. It can be said that traditional convection type boilers are treated as outdated, and their complete replacement is only a matter of time. The secret lies in the fact that the efficiency of condensation boilers can be 10-15% higher than that of convection, due to which the costs when buying more expensive condigances pay off in Europe in 4-5 years. Plus, you get environmentally cleaner equipment, since the emission of harmful substances into the atmosphere in condensation boilers is small, several times lower than that of traditional models.
Buyers gradually began to understand that the cost of acquiring a condensation boiler should be compensated by a high efficiency of this device.
Wall Condensation Gas Copper Buderus Logamax Plus GB162 with a capacity of 70, 85 and 100 kW. Photo: Bosch.
The increase in the efficiency is ensured by condensation of vapors contained in smoke gas together with combustion products. The smoke is cooled on the secondary heat exchanger (the coolant from the reverse line of the heating system) is supplied to about 55-57 ° C, the water vapors are condensed on the heat exchanger, and additional energy that gives the efficiency of the efficiency is released. The condensation mode will work only under conditions when the temperature of the coolant in the return does not exceed 57 ° C and the greatest efficiency is achieved at low (30-35 ° C) coolant temperatures in the return.
Separate smoke system with adapter. Photo: Boris Bezel / Burda Media
Buyers prefer condensation boilers most often in the wall version. Photo: shutterstock / fotodom.ru
Why the cost of condensation boilers is noticeably higher than usual? This is largely due to the materials from which the heat exchanger is made. The resulting condensate contains acids and other aggressive chemical compounds, which are capable of completely output in a short time, say, the heat exchanger from the cast iron (it is no coincidence that the temperature of the flue gases in convection boilers is specially supported at the output not lower than 140-160 ° C). These details in condensation boilers are made of stainless steel and similar, fairly expensive materials.
Ultra-compact (540 × × 365 × 370 mm, weight 25 kg) Condensation boiler NaNeo Plus (de Dietrich). Photo: Boris Bezel / Burda Media
In Russia, the number of sales of condensation boilers is growing, but the pace is low - hardly the amount of their sales is more than 5% of the market. The reason for the lack of interest lies in the low cost of gas: in some European countries, it costs the consumer 5-6 times more expensive than in Russia. Accordingly, the payback period of such boilers in Russia is becoming too large, sometimes more than 10 years, which constitute the entire calculated service life of the boiler itself. In addition, constructive condensation boilers are arranged in such a way that the highest efficiency is achieved with small, "European" frosts, and with strong (-20 ... -25 ° C) it decreases, and the difference between the efficiency of condensation and convection boilers becomes small, Somewhere about 5% (and the payback period becomes completely "indecent").
The use of condensation boilers is especially relevant in systems with low temperature modes (for example, warm floors).
But it seems that the same story will take place with condensation boilers as with energy-saving light bulbs. The gas will grow in price, the equipment - on the contrary, becoming cheaper, and little by little all users will move to more economical equipment. Therefore, building a new home, it is better to immediately lay in the project the possibility of placing a condensation boiler: how to equip the air to the boiler for normal operation and the condensate neutralization formed during operation.
Double-circuit boilers allow you to organize both the heating of dwellings and the supply of it with hot water. Photo: shutterstock / fotodom.ru
Convection boilers
Coaxial chimneys for condensation boilers (Royal thermo): Chimney no frost for low temperatures (up to -50 ° C). Photo: Boris Bezel / Burda Media
Models of traditional (convection) boilers are also constantly complicated by design. So, today the devices with the possibility of connecting weather-dependent automation are in demand. Depending on the settings, external temperature regulators give the boiler to reduce or increase the heating intensity. Such possibilities are already provided in many convection boilers: in the series Vaillant Turbofit, Bosch Gaz 6000 W, Ariston Genus Premium EVO.
Universal model. Photo: Boris Bezel / Burda Media
In many models there are several modes of operation besides the main one. For example, in the WBN6000-35CR (BOSCH) device, two additional modes are provided: Comfortable and ECO. In comfortable mode, the boiler constantly supports the specified temperature in the secondary heat exchanger, thereby reducing the waiting time during the selection of hot water. In ECO mode, heating to a predetermined temperature is carried out only directly when the hot water is selected.
An example of a device of a double-circuit condensation boiler: 1 - collector of combustion products; 2 - primary heat exchanger; 3 - burner; 4 - flame control electrode; 5 - Secondary heat exchanger of the DHW; 6 - siphon for condensate removal; 7 - Heating Contour Safety Valve; 8 - control panel; 9 - flow sensor in the DHW circuit; 10 - simulated circular pump; 11 - pressure relay; 12 - muffler flue gases; 13 - burner fan; 14 - ignition electrodes; 15 - Spreading the combustion products
In most models, a closed combustion chamber is used, which air is supplied using a special fan. This is a more complex design option, and, unlike traditional open cameras, it allows you to achieve better power management, which generally provides a higher efficiency. The disadvantage is that a constant connection to the power grid is required.
Many convection boilers are optimized and the control system is optimized. A variety of additional devices are increasingly used, such as remote controls - they are equipped, say, ATMO and DELUXE (NAVIEN) series. And in the SMART series you can use as a smartphone or tablet control panel.
What limits the distribution of condensation boilers? First, they are quite expensive. The price difference can be 30, and even 100%. But note that the price of the boiler needs to add the cost of acquiring and installing the system of gas distribution and smoke removal. For condensation boilers, the system data is much cheaper, so the turnkey price for the final client will be comparable. Secondly, to connect condensation boilers, the installation of the low-temperature heating system is required. Maximum efficiency can be achieved only when using water heat floors. However, the complexity of the installation, the likelihood of the pipeline leakage and the restless faith in the exclusiveness of radiator heating does not allow warm floors to gain popularity among consumers.
Sergey Chernov
Product Manager "Vailant Group Rus"