Efficiency of a gas boiler: characteristics, calculations, tips for increasing efficiency

Efficiency of a gas boiler: characteristics, calculations, tips for increasing efficiency
Efficiency of a gas boiler: characteristics, calculations, tips for increasing efficiency

In our time, gas has already been supplied to many small settlements, even quite remote from cities. And most of the inhabitants of villages and towns in Russia today use boilers rather than wood-burning stoves to heat their homes. Such equipment is installed in the building in one of the utility rooms. Next, a chimney and a heating circuit are connected to it.

What is efficiency

Gas boilers are produced in our time by many companies, both domestic and foreign. When choosing such equipment, the owners of private houses in Russia, unfortunately, look mainly only at its price and power. Meanwhile, a very important parameter that allows you to choose a good heating unit is efficiency. A gas boiler, among other things, must be highly productive.

Boiler improvement

The higher the efficiency of such equipment, the less in the future the owners of the house will have to pay for blue fuel. They call the efficiency of gas boilers the ratio of the spentfuel for heat output.

Formula for calculating the average efficiency

Efficiency is also indicated in the technical passport of the boiler. However, in this case, the consumer is provided only with an average indicator, which is calculated by firms engaged in the manufacture of such equipment, according to the following formula: n=(Q/Qo)100%.

Here Q is the heat that was managed to be isolated, accumulated and used for space heating; Qo - the total amount of thermal energy released during fuel combustion.

Unfortunately, only the average efficiency can be outpaced by this formula. Gas boilers with a high performance indicator on the modern market are presented in a rather large assortment. For some modern brands of such units, the efficiency can reach 98%. This is, of course, a lot. However, in practice, modern gas units, unfortunately, often do not show such effective operation. During the operation of such equipment in private homes, various kinds of heat losses appear, which negatively affects the efficiency. That is, when installed in a house, gas boilers usually lose performance.

Coaxial chimneys

Actual efficiency - formula

On site, the efficiency of such equipment is usually determined by the following formula: η=100 - (q2 + q3 + q4 + q5 + q6).


  • q2 - heat losses due to heated combustion products leaving the pipe;

  • q3 - losses due to incorrectly chosen proportions of the gas mixture (underburning);

  • q4 - losses due to soot inside the boiler and mechanical underburning;

  • q5 - losses due to fluctuations in outside air temperature.

In this case, it is believed that the q2 indicator affects the boiler efficiency the most. That is, to the greatest extent, the performance and efficiency of a gas heating unit depends on how much heat it induces literally “flies into the pipe.”

Modern gas boilers

Which boilers are more efficient

Domestic manufacturers currently produce quite powerful and reliable gas heating equipment. However, in our country, unfortunately, too much attention is still not paid to saving resources. Therefore, imported gas boilers have the highest efficiency today. In particular, this applies to low-temperature condensing models, in which the heat carrier heating index 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, on the modern market are:

  • Buderus.

  • Vissman.

  • Baxi.

  • Vailant.

De Dietrich is also considered a very good brand of heating units with high efficiency.

How to increase the efficiency of a gas boiler: basic ways

If the boiler in the house does not work with proper performance, its owners will have to overpay for gas consumption, which, of course, will have the most negative impact onfamily budget. To increase the performance of the heating unit and thereby avoid unnecessary expenses, you can:

  • modify the chimney or improve exhaust gas conditions;

  • clean the combustion chamber;

  • clean or replace home heating pipes;

  • 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 discharges combustion products that affects the performance of boilers very much. If the chimney becomes clogged with soot, this will reduce its diameter and, accordingly, the draft. Experts recommend checking the condition of the gas exhaust pipe at least once a year.

Gas boiler chimney

A closed-type boiler to increase efficiency is best connected to a coaxial chimney. In this case, the air will begin to enter the combustion chamber through the outer cavity of the two-cavity pipe, already being slightly heated. This, in turn, will reduce the initial heat costs by several percent.

Additional measures

Also in the house you can install a recirculation system for combustion products. In this case, the smoke will pass through the broken channel and afterair is added to the burner again.

In severe frosts, experts advise reducing the draft of the chimney a little. This will also slightly increase the efficiency of a floor or wall-mounted gas boiler. To reduce draft, you can use a special device that is attached directly to 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. By correctly adjusting its position, you can quite seriously increase the efficiency of a gas boiler.

If the boiler damper is opened too far, too much air will enter the combustion chamber. In this case, a draft will form in the furnace, pulling some of the blue fuel out into the street along with the products of combustion.

An even more serious decrease in the efficiency of a gas boiler can cause the damper to close too much. In this case, little air will enter the combustion chamber. As a result, part of the gas simply will not burn and will also go out into the chimney along with smoke. The efficiency of the heating unit can decrease with this damper position by as much as 7%.

It will not be difficult 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 damper until the boiler thermometer shows the highest heating of the coolant in the heating system.

Cleaning the combustion chamber

Blue fuel is distinguished primarily by the fact that when it is burned, it does nottoo much soot is produced. Of course, it is necessary to clean the furnace of a gas-fired boiler less often 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 once every 3 years.

Cleaning the combustion chamber

Scaling in pipes

Be sure the owners of private houses, in order not to spend a lot of money on gas, you need to monitor the condition of the mains of the heating system. The normal clogging of pipes can also reduce the performance of the boiler. Experienced owners of country houses, for example, do not recommend changing the coolant in the heating circuit too often. It is undesirable to drain water from the mains 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 in the form of sediment.

What changes can be made to the design

To increase the efficiency of wall-mounted gas boilers or floor-standing ones, special turbulators can be installed between the combustion chamber of the unit and its heat exchanger. This is the name of special plates that can significantly increase the area of ​​​​removal of heat.

Also, the operation of the boiler can be controlled 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 set up and synchronize the operation of the boiler in accordance with the readings of the latter.

Turning on the burner of gas heating units when the air temperature in the premises drops below 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 burn out. To reduce losses, the usual "lighter" in the boiler can be replaced with a "piezo". Such a device will work no worse than a traditional one, and the savings from its use are very significant.

Other changes

Very good performance indicators are available, among other things, for gas heating units equipped with modulating burners. Modern boilers from the best European manufacturers are initially supplemented with similar two-level or fully modulated elements. Burners of this type are able to 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.

Gas boiler burner

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. The heat balance of the unit in this caseincreases upwards.

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 country houses to immediately purchase economical and productive equipment of this type. The highest efficiency, as already mentioned, is characterized by condensing gas boilers.

On the domestic market, such equipment has appeared 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 efficiency of such equipment is an order of magnitude higher than that of conventional heating units.

Many manufacturers of such boilers even claim 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%. Such an indicator cannot exceed this figure at all. Of course, even the most advanced heating unit is not capable of increasing the amount of heat when burning the same volume of blue fuel.

Condensing gas boiler

But still, the efficiency of gas condensing heating boilers is much higher than conventional ones. According to experts, it can reach up to 98-99%.

In terms of gas consumption efficiency, condensing boilers are thus significantly superior to simple ones. However, unfortunately, at the same time, such equipment costs much more than traditional ones. To purchase or notthe unit is a matter of choice for the owners of the gasified house themselves. Most likely, during the operation of a gas boiler with high efficiency condensing, the difference in cost will eventually pay off. But this will still not happen too quickly, for which buyers should be prepared in advance.

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