Various gas heating boilers: the principles of their work

If the country house has the ability to connect to a gas pipeline, then it will be very convenient for you to heat your house by installing Lemax gas boilers or any other brands as heaters. The most important thing is that you manage to correctly calculate the power of the heater in relation to the living space of the room and the amount of coolant in the radiator circuit or underfloor heating.

And whatever brand you choose - Wisman, Mimax, Beretta - it is important that they are suitable for the type of heat exchanger heating, which will be discussed below, and in addition, we will watch a video clip about the boilers.

Principle of operation

Note. Depending on the heating circuit, it is also necessary to choose a heating gas boiler, which can be either high-temperature (convection) or low-temperature (condensing). So, if radiators need a fluid temperature of about 60-80? C, then for a warm floor enough 30-50? C.

Convection units

• Gas-fired boilers of convection type are most in demand in the Russian Federation, for example, it can be a wall-mounted or floor-mounted version of the Daewoo DGB-100 MSC, which you see in the top photo. It depends on the fact that in most cases, we prefer radiators, and not floor heating systems - a long-term habit and fear of the new affects. Nevertheless, such models are presented with powerful options and in some cases of them even complete a small central boiler room for several multi-storey buildings.

• The principle of operation of such units operates according to the same scheme - the fuel goes through the pipeline to the burner, which with its flame heats the coolant, while modern burners most often function both on propane and on natural gas. The main disadvantage of traditional boilers before condensation is that the secondary heat that is generated in the combustion chamber is not used to increase efficiency, but is discharged through the chimney to the street.
• The optimal temperature range, whether German WOLF, Czech PROTHERM or Finnish diesel-gas TERMAX, is in the range of 60-80? C, due to the desire for the longest operating life of the heat exchanger. These restrictions are due to the fact that at a temperature of 55-57? C (critical point) acid condensate accumulates on the heat exchanger, which destroys its walls. Acid evaporation is formed as a result of thermal decomposition or, simply, the combustion of gas.

Note. In the case of combining two circuits - radiators and a heated floor, the instruction recommends using traditional models, and lowering the temperature of the heat carrier to a warm floor there is carried out by a three-way valve.

Condensing units

• Of course, compared to convection, condensing gas boilers for heating do not enjoy such popularity in Russia, especially since the price of such a device is much higher, but this is due to the acid condensate filtration system. Those users who did decide to make such an acquisition are unlikely to regret it, since the savings here are obvious - the efficiency of such units in some cases reaches 111%!

• Condensation gas heating boiler operates according to the following principle: natural gas enters the burner, the flame of which heats the heat exchanger, but the secondary heat is not removed from the fuel chamber to the street, but is used for secondary heating. Considering that such models are designed for an optimal temperature of 30-50? C, acid condensate will always be formed there, but it will not harm the heat exchanger, as it falls down. After that, through a special pipeline with filters, it is diverted to a certain capacity, practically losing its toxicity.

Heat exchangers

Any heating boiler on gas has a heat exchanger in its configuration, which can be either bithermic, as you see in the upper figure, or separate. The bitermic version consists of two connected hollow profiles, that is, it is a pipe in a pipe with a lamellar coating to protect the corrosion. Liquid in the inner pipe is fed to the hot water system, and in the outer - to the heating circuit.

The presence of such a node facilitates the mass and dimensions of the boiler, for example, in the SIGNAL or ISHMA marks (although a separate version is possible there). In such cases, there is only one node and this. Naturally reduces its weight and size, but, in addition, for units with such a device does not need a three-way valve for hot water, because there the water temperature is lower (30? C) than in the heating circuit.

Despite all the advantages, bithermic heat exchangers are unsuitable for working with hard water - salts and slags deposited on the walls of pipes, block the passage, which after this is almost impossible to clean. The fact is that when cleaning these substances, falling off the metal, do not dissolve to the end, but look like small pieces that get stuck in congestion when cornering and clog the passage.

If there is hard water in your area, then it is best to choose AOGV with a separate heat exchanger that is easy to clean, and it does not clog so quickly, for example, CONORD, KEBER or TERMONA. This is possible due to the larger internal diameter of the pipes, and although this option will cost a little more, you will save on a longer service life.

Overview of some models

The double-circuit gas boiler for heating Dani will not use the air from the room where it is installed - the air intake comes from the street, and the products of thermal decomposition are discharged through a coaxial flue. The nominal pressure at the gas intake is 1274PA, and the working pressure of the hot water is not more than 0.65kPa. If the nominal pressure of the energy carrier does not exceed 1274 Pa, then its consumption is not more than 0.8 m.³/hour.

The double-circuit bithermic traditional heating unit NEVA LUX, which you see in the top photo, is produced in Russia, the hot water supply is 14 l / min, designed for a maximum area of ​​240m². The nominal power of such a device is 18 kW, copper heat exchanger, the efficiency reaches 90%, the maximum temperature of thermal decomposition products is 130? C, the minimum is 100? C. Dimensions (height / width / depth) 720x410x326 mm, weight 34.5 kg, 2 years warranty.

The Waxi gas unit, which you see in this photo, is a wall-mounted dual-circuit unit with a maximum power of 14kW (enough for a room of 140m²) with a maximum gas consumption of 1.63 m³/hour. At full power, the efficiency of the device is 92.9%, and if it works in the mode of 30% power, the efficiency will be 90%, the temperature of the DHW is 30-55? C. Dimensions (height / width / depth) 700x400x280 mm, weight 29.0 kg, 2 years warranty.

The heating boiler Aton is a condensing unit designed for low-temperature circuits with maximum power, provided that the condensation mode is observed to be 24.6 kW, and 22.1 kW in a typical one. For heating in the mode of 60-80? C 6,3-21,4kW, and for 30-50? C - 6,9-21,7kW, the performance of hot water supply? T 30? C - 10 l / min.

The Beretta Exclusive Green 30 CSI model of condensation type, designed for low-temperature circuits, with a maximum power subject to the observance of the condensation mode of 30 kW. At the same time, in the mode of 60-80? C 99.1 kW, and for 30-50? C - 31.41 kW, the performance of hot water supply? T 30? C - 10 l / min. In the range of 60-80? C, the efficiency is 95.5%, and in the range of 30-50? C - 105.2%. Beretta works on both natural and liquefied gas.

Conclusion

In conclusion, we can say that there are also gas cast-iron heating boilers that you can install on the floor with your own hands, and in most cases, these are double-circuit models of convection type. When installing for certification, a representative of a gas company with a license should be called - so the warranty period will be calculated not from the date of purchase, but from the date of installation (see also the article Ferrol gas heating boilers and their features).