In many small towns even quite remote from cities, gas has already been conducted in our time. And most of the inhabitants of villages and towns in Russia today do not use wood-burning stoves, but boilers to heat houses. Such equipment is installed in a building in one of the utility rooms. Next, a chimney and a heating circuit are connected to it.
What is efficiency?
Nowadays, many companies both domestic and foreign produce gas boilers. When choosing such equipment, owners of private houses in Russia, unfortunately, look mainly only at its price and capacity. Meanwhile, efficiency is a very important parameter that allows you to choose a good heating unit. A gas boiler, among other things, should be characterized by high performance.
The higher the efficiency the similar equipment has, the less the subsequent owners of the house will need to pay for blue fuel. The efficiency of gas boilers is called the ratio of spent fuel on heat output.
The formula for calculating the average efficiency
Efficiency is indicated including in the technical passport of the boiler. However, in this case, the consumer is provided with only an average indicator, which is calculated by firms manufacturing such equipment, according to the following formula: n = (Q / Qo) * 100%.
Here Q is the heat that was able to separate, accumulate and use for space heating; Qo is the total amount of thermal energy released during fuel combustion.
Unfortunately, only an average efficiency can be outperformed by such a formula. Gas boilers with a large performance indicator in the modern market are presented in a rather large assortment. For some modern brands of such units, the efficiency can reach 98%. This, of course, is a lot. However, in practice, modern gas units, unfortunately, often do not show such effective operation. In the process of operating such equipment in private homes, various kinds of heat loss appear, which in the most negative way affects efficiency. That is, when installed in a house, gas boilers usually lose productivity.
Actual Efficiency - Formula
In place of the efficiency of such equipment is usually determined by the following formula: η = 100 - (q2 + q3 + q4 + q5 + q6).
Here:
q2 - heat loss due to heated combustion products leaving the pipe;
q3 - losses due to incorrectly selected proportions of the gas mixture (underburning);
q4 - losses due to soot inside the boiler and mechanical underburning;
q5 - losses due to fluctuations in the outdoor temperature.
At the same time, it is believed that the q2 coefficient most affects the efficiency of the boiler. That is, to the greatest extent the productivity and efficiency of a gas heating unit depends on how much heat it induces in the literal sense of the word “flies into the pipe”.
Which boilers have greater efficiency
Domestic manufacturers currently produce quite powerful and reliable gas heating equipment. However, in our country, unfortunately, still not paid too much attention to saving resources. Therefore, the highest efficiency for today have imported gas boilers. This is especially true for low-temperature condensation models, in which the heating medium does not exceed 70 ° C and the exhaust gases 110 ° C.
The most productive brands of gas boilers, the efficiency of which is very high, in the modern market are:
Buderus.
Wissman.
Baxi.
Vailant.
Also a very good brand of heating units with high efficiency is considered to be “De Dietrich”.
How to increase the efficiency of a gas boiler: the main methods
If the boiler in the house does not work with the proper performance, its owners will have to overpay for gas consumption, which, of course, will negatively affect the family budget. To increase the productivity of the heating unit and thereby avoid unnecessary waste, you can:
modify the chimney or improve the conditions for exhaust gas;
clean the combustion chamber;
to clean or replace the heating system highways;
make changes to the design of the boiler;
adjust the proportions of the gas mixture in the combustion chamber using a damper.
Using such techniques, it is possible to increase the efficiency of both a double-circuit gas boiler and a single-circuit one. Such methods are also suitable for wall or floor gas heating units.
What to do with the chimney
It is the condition of the pipe that exhausts the products of combustion that influences boiler performance very much. If the chimney is clogged with soot, this will reduce its diameter and, accordingly, draft. Experts recommend checking the condition of the pipes that exhaust the combustion products of gas at least 1 time per year.
A closed boiler to increase efficiency is best connected to a coaxial chimney. In this case, air will begin to enter the combustion chamber through the outer cavity of the two-cavity pipe, already being slightly warmed up. This, in turn, will reduce the initial heat consumption by a few percent.
Additional measures
Also in the house you can install a recirculation system of combustion products. In this case, the smoke will pass through the broken channel and after mixing air again to the burner.
In severe frosts, experts advise to reduce the chimney draft a little. It will also allow you to slightly increase the efficiency of a gas boiler floor or wall. To reduce traction, you can use a special device that is mounted directly on the chimney.
Adjusting the proportions of the gas mixture
In the design of any modern heating unit, among other things, there is such an element as a damper. Correctly adjusting its position, you can quite seriously increase the efficiency of a gas boiler.
If the boiler shutter is opened too much, a lot of air will begin to flow into the combustion chamber. In this case, a draft will form in the furnace, pulling some of the blue fuel into the street along with the combustion products.
An even more serious decrease in the efficiency of the gas boiler can cause the damper to close too tightly. In this case, little air will enter the combustion chamber. As a result, part of the gas simply will not burn out and will also exit into the pipe along with the smoke. The efficiency of the heating unit can decrease with this position of the damper by as much as 7%.
It will be easy to adjust the proportions of the combustible mixture inside the boiler furnace on your own. This can be done experimentally. The owner of the house just needs to push and pull the shutter until the boiler thermometer shows the highest heating of the heat carrier in the heating system.
Cleaning the combustion chamber
Blue fuel is primarily distinguished by the fact that when it is burned, too much soot is not formed. Of course, it is less necessary to clean the furnace of a gas-fired boiler than solid-fuel equipment of this type. But still, it is necessary to wash the combustion chamber of such heating units from time to time. Experts believe that owners of gas boilers need to do such cleanings at least 1 time in 3 years.
Scale in pipes
It is imperative that the owners of private houses, in order not to spend a lot of money on gas, need to monitor the condition of heating system highways. Reducing boiler performance can also include regular pipe clogging. Experienced owners of country houses, for example, do not advise changing the coolant in the heating circuit too often. It is undesirable to drain water from highways even at the end of the cold season. The fact is that any water from a well, a well and a centralized system contains a huge amount of dissolved mineral substances, which subsequently precipitate in the pipes.
What changes can be made to the design
To increase the efficiency of wall-mounted gas boilers or floor-mounted, special turbulators can be installed between the furnace chamber of the unit and its heat exchanger. So called special plates that can significantly increase the area of heat energy extraction.
Also, the operation of the boiler can be regulated using temperature sensors. Such devices are installed in the premises of the house and turn on / off the burner of the heating unit, depending on the heating of the air to the temperature set by the owners. When using sensors, it is important to correctly configure and synchronize the operation of the boiler in accordance with the latter.
The inclusion of a burner of gas heating units when the air temperature in the rooms is lower than the specified parameters comes from a special “lighter”. They call it a small burner, the gas on which never fades. Such a “lighter” cannot burn a lot of blue fuel. However, during the season, due to its work, several cubic meters of blue fuel often still burns. To reduce losses, the usual “lighter” in the boiler can be replaced with a “piezo”. Such a device will work no worse than the traditional one, and the savings from its use are very significant.
Other changes
Among other things, very good performance indicators are also available for gas heating units equipped with modulation burners. Modern boilers from the best European manufacturers are initially supplemented by similar elements of two-level or fully modulated. Burners of this type can independently adapt to the actual operating parameters of the heating system installed in the house. Thus, the percentage of underburning in boilers of this design is reduced to a minimum.
In conventional heating units, home owners can, among other things, try to change the position of the burner. Installing this element closer to the water circuit allows you to increase the efficiency of the boiler by several percent. In this case, the heat balance of the unit increases.
Condensing boilers
Thus, it will be relatively easy to increase the efficiency of a gas boiler. But of course, it is better for owners of suburban homes to immediately acquire economical and productive equipment of this type. The highest efficiency, as already mentioned, is distinguished by condensing gas boilers.
Such equipment has appeared on the domestic market relatively recently. The efficiency of these boilers is determined primarily by the fact that they additionally use the energy generated due to the condensation of water vapor from the exhaust gases. The effectiveness of such equipment is an order of magnitude higher than that of conventional heating units.
Many manufacturers of such boilers even assure that they produce gas boilers with an efficiency of 100% or higher - 108-109%. Of course, such claims are disputed by experts. After all, as you know, the efficiency of any equipment rarely reaches 100%. But such an indicator cannot exceed this figure at all. To increase the amount of heat when burning the same volume of blue fuel, of course, not even the most advanced heating unit is capable of.
Nevertheless, the efficiency of gas condensing heating boilers is much higher than conventional. According to experts, it can reach 98-99%.
In terms of gas consumption, condensing boilers are thus far superior to simple boilers. However, unfortunately, this equipment is much more expensive than traditional equipment. To purchase or not such an aggregate is a matter of choosing the owners of the gasified house themselves. Most likely, during the operation of a gas boiler with a high condensation efficiency, the difference in cost will ultimately pay off. But this still does not happen too quickly, for which buyers should be prepared in advance.