How to calculate gas consumption for heating a house in accordance with standards

Determining the amount of costs for centralized or autonomous heating of a private house is carried out at the design stage of the building, or before choosing the type of energy carrier or the optimal model of the boiler unit.

What factors are taken into account when calculating gas consumption for heating a house, and how to determine the average consumption based on a simplified methodology without resorting to the services of specialists, we will consider in our article.

Determining factors of gas mixture consumption

Heating a home using natural gas is considered the most popular and convenient today. But due to the rise in price of “blue fuel”, the financial costs of homeowners have increased significantly. Therefore, most zealous owners today are concerned about the average gas consumption for heating a house.

The main parameter when calculating fuel consumption spent on heating a country house, are the heat losses of the building.

It’s good if the home owners took care of this during the design process. But in most cases, in practice it turns out that only a small part of homeowners knows the heat losses of their buildings.

The consumption of the gas mixture directly depends on the efficiency and power of the boiler generator.

No less influential are also:

• climatic conditions of the region;
• design features of the building;
• number and type of windows installed;
• area and height of ceilings in rooms;
• thermal conductivity of the building materials used;
• quality of insulation of the external walls of the house.

Keep in mind that the recommended nameplate power of the installed unit demonstrates its maximum capabilities. It will always be slightly higher than the performance indicators of the unit operating in normal mode when heating a particular building.

The power of the installed unit is calculated in strict accordance with current regulatory requirements, taking into account all of the above factors

For example, if the passport boiler power 15 kW, then the system will actually function effectively with a thermal power of about 12 kW. A power reserve of about 20% is recommended by experts in case of accidents and extremely cold winters.

Therefore, when calculating fuel consumption, you should focus specifically on real data, and not be based on maximum values ​​​​calculated for short-term operation in emergency mode.

It is recommended to buy a gas unit with a power reserve of approximately 20% in case of emergencies and cold winters. For example, if the calculated thermal power is 10 kW, then it is recommended to purchase equipment with a nameplate power of 12 kW

Average flow calculator

The nominal gas consumption for the past heating period is not so difficult to calculate. You just need to take meter readings every month. After the end of the season, summarize the monthly readings. Then calculate the arithmetic mean.

If you need to find out the nominal values ​​at the stage of designing a house, or when choosing an effective, but at the same time economical heating equipment, you will have to use formulas.

When arranging autonomous heating for a country cottage or apartment, average parameters are used to determine heat loss

To obtain approximate calculations, the specific heat consumption is determined in two ways:

1. Based on the total volume of heated rooms. Depending on the region, 30-40 W are allocated for heating one cubic meter.
2. According to the overall square footage of the building. The basis is that 100 W of heat is spent to heat each square of room area, the height of the walls in which on average reaches 3 meters. When determining the value, they also focus on the region of residence: for southern latitudes - 80 W/m², for northern ones – 200 W/m².

The main criterion that must be taken into account when making calculations is the required thermal power to ensure conditions for high-quality heating of premises and replenishment of its heat losses.

The basis for technological calculations is the average proportion at which 1 kW of thermal energy is consumed per 10 square meters of area. But it is worth considering that such an average approach, although convenient, is still not sufficiently capable of reflecting the real conditions of your building, taking into account the climatic region of its location.

Using a simplified calculation method, it is taken as a basis that to heat 10 square meters of a private house, 1 kW of thermal power generated by a generator is required

By correctly calculating the estimated fuel consumption, you can clarify for yourself what measures should be taken to reduce its consumption. As a result, the item of regular payments for consumed “blue fuel” will be reduced.

Mains gas for heating needs

A G20 gas mixture is supplied to private homes from a centralized pipeline. In accordance with the adopted standard DIN EN 437, the minimum specific heat value for the combustion of G 20 fuel is 34.02 MJ/cubic meter.

If a highly efficient condenser boiler is installed, the minimum specific heat value for “blue fuel” category G 20 is 37.78 MJ/cu. meter.

You can order a calculation of the heat losses of a residential building in order to create an “accounting” of seasonal costs and clarify for yourself whether there is a need to do insulation from a design organization

Formula for calculating fuel consumption

To determine gas consumption, taking into account the energy potential inherent in it, a simple formula is used:

V=Q / (Hi x efficiency)

Where:

• V – the desired value that determines the gas consumption for generating thermal energy is measured in cubic meters/hour;
• Q – the amount of calculated thermal power expended to heat the building and provide comfortable conditions, measured in W/h;
• Hi – the minimum value of specific heat during fuel combustion;
• Efficiency – efficiency factor of the boiler.

The efficiency of a boiler generator shows the efficiency of using the thermal energy generated during combustion of the gas mixture, which is directly spent on heating the coolant. It is a passport value.

In the passports of modern boiler units, the coefficient is indicated by two parameters: by higher and lower calorific value. Both values ​​are written through the fractional line “Hs/Hi”, for example: 95/87%. To obtain the most reliable calculation, take as a basis the value specified in the “Hi” mode.

The lowest value of the specific heat of combustion of gas is a tabular value, the parameters of which correspond to the accepted standards DIN EN 437

The “Hs” value indicated in the table determines the highest heat value of gas combustion. It is indicated in the table for the reason that the water vapor released during gas combustion is also capable of converting latent thermal energy. If you use this thermal energy wisely, you can increase the total return on the consumed fuel.

The operation of new generation boilers – condenser units – is based on this principle. In them, due to the conversion of steam into an aggregate liquid state, an additional 10% of heat is generated.

In addition to G20 gas, an analogue of the second group, G 25, can also be used for domestic purposes. G 20 gas is extracted from Siberian deposits, and G25 is supplied from Turkmenistan and the Volga region. The difference between them is that G25 emits 15% less heat when burned.

Gas grade G25 is characterized by an increased percentage of nitrogen, due to which its energy potential is 15% lower than its natural analogue G20

You can find out what type of gas “flows” in the pipeline from the gas supply company in your region.

An example of calculating network gas consumption

We propose to consider an example of calculating gas consumption for heating a country cottage, the initial data of which has the following parameters:

• The area of ​​the premises reaches 100 square meters. meters;
• recommended heat unit power – 10 kW;
• The boiler efficiency reaches 95%.

To simplify the calculation, joules are converted to another unit of measurement - kilowatts. So, provided that 1 kW = 3.6 MJ, the calorific value of G 20 gas will be 34.02/3.6 = 9.45 kW.

It is also worth considering that the recommended power of the heat generator, indicated as 10 kW, will only be required to heat rooms under the most unfavorable conditions. In fact, throughout the entire heating season, the number of such unfavorable days will be counted in single units.

With a well-thought-out and equipped heating system, the installed boiler unit will definitely not work around the clock

On the remaining days of the cold season, significantly less power is used to heat the building. Therefore, to obtain correct calculations, as well as to determine the average, and not the peak, consumption of “blue fuel”, the boiler power readings are not 10 kW, but “half” 5 kW.

Substituting the obtained data into the formula, perform the calculations: V = 5/(9.45 x 0.95). It turns out that to heat a cottage with an area of ​​100 square meters, the gas consumption is 0.557 cubic meters per hour.

Having clarified the tariffs for paying for one cubic meter of “blue fuel”, it will not be difficult to calculate material costs for the entire heating period

Based on the data obtained through simple calculations, it is not difficult to calculate gas consumption for the entire heating season, which in mid-latitude regions lasts about 7 months:

• For a day it is 0.557 x 24 = 13.37 m³.
• For a month 13.37 x 30 = 401.1 m³.
• For the heating season lasting 7 months 401.1 x 7 = 2807.4 m³.

Knowing the price of one cubic meter of “blue fuel”, it will not be difficult to plan both monthly expenses and “accounting” for the entire functioning of the heating system.

Consumption of liquefied propane-butane mixture

Not all owners of country houses have the opportunity to connect to centralized gas pipeline. Then they get out of the situation using liquefied gas. It is stored in pits installed gas holders, and are replenished using the services of certified companies supplying fuel.

Liquefied gas used for domestic purposes is stored in sealed containers and reservoirs - propane-butane cylinders with a volume of 50 liters, or gas holders

If liquefied gas is used to heat a country house, the calculation formula is taken as the basis. The only thing you need to take into account is that the bottled gas is a G30 mixture. In addition, the fuel is in an aggregate state. Therefore, its consumption is calculated in liters or kilograms.

Formula for calculating fuel mixture consumption

A simple calculation will help you estimate the cost of a liquefied propane-butane mixture. The initial construction data is the same: a cottage with an area of ​​100 square meters, and the efficiency of the installed boiler is 95%.

When calculating, it should be taken into account that fifty-liter propane-butane cylinders, for safety reasons, are filled to no more than 85%, which is about 42.5 liters

When performing calculations, we focus on two significant physical characteristics of the liquefied mixture:

• The density of bottled gas is 0.524 kg/l;
• The heat released during the combustion of one kilogram of such a mixture is equal to 45.2 MJ/kg.

To facilitate calculations, the values ​​of heat released, measured in kilograms, are converted into another unit of measurement - liters: 45.2 x 0.524 = 23.68 MJ/l.

After which joules are converted to kilowatts: 23.68/3.6 = 6.58 kW/l. To obtain correct calculations, the same 50% of the recommended power of the unit is taken as a basis, which is 5 kW.

The obtained values ​​are substituted into the formula: V = 5/(6.58 x 0.95).It turns out that the consumption of the G 30 fuel mixture is 0.8 l/h.

An example of calculating liquefied gas consumption

Knowing that on average 0.8 liters of fuel are consumed per one hour of operation of a boiler generator, it will not be difficult to calculate that one standard cylinder with a 42-liter refill will be enough for approximately 52 hours. This is a little more than two days.

For the entire heating period, the consumption of the combustible mixture will be:

• For a day 0.8 x 24 = 19.2 liters;
• For a month 19.2 x 30 = 576 liters;
• For the heating season lasting 7 months 576 x 7 = 4032 liters.

To heat a cottage with an area of ​​100 square meters you will need: 576/42.5 = 13 or 14 cylinders. For the entire seven-month heating season, you will need 4032/42.5 = from 95 to 100 cylinders.

To accurately calculate the number of propane-butane cylinders needed to heat a cottage for a month, you need to divide the consumed monthly volume of 576 liters by the capacity of one such cylinder

A large volume of fuel, taking into account transportation costs and the creation of conditions for its storage, will not be cheap. But still in comparison with the same electric heating such a solution to the issue will still be more economical, and therefore preferable.

Ways to reduce consumption

The main reason for significant heat losses, which lead to ineffective consumption of the thermal energy released by the boiler unit, is insufficient insulation of the structural elements of the house. Up to 40% of heat is wasted through “cold bridges.”

Up to 35% of the heat generated by the boiler leaks through windows with poor-quality frames, up to 25% through the walls of the house, and up to 15% through the roof and entrance doors.

In order not to waste money every time heating the street, it is better to spend money once on quality insulation of buildings. Believe me, the costs for it will be fully recouped in 3-4 years.

Thermal insulation of a house includes:

1. Insulation of walls. The easiest to implement and affordable option is the installation of polystyrene foam panels. The thickness of the panels is chosen based on the climatic conditions of the construction region, the thickness of the walls of the building and the type of material used in their construction.
2. Insulation of the roof or attic floor. For these purposes, sawdust, mineral wool or polystyrene foam tiles are used. The heat-insulating material, produced in the form of slabs, is mounted on the internal walls of the attic space or placed between the floor beams.
3. Insulation of floors. Not only concrete, but also wooden structures. To form a thermal insulating layer, bulk and slab materials such as expanded clay and expanded polystyrene are used.
4. Replacement of windows. The most reliable shield that prevents the penetration of cold into heated rooms will be PVC windows with high-quality double-glazed windows. They are made for a specific window. Thanks to this, they hermetically close the window opening, reliably protecting household members not only from the “leakage” of heat, but also from the penetration of street noise.

Proper thermal insulation allows you to reduce heat loss to a minimum.

In addition to high-quality insulation, to increase the efficiency of heat transfer, experts recommend using other equally effective measures

Experts include additional measures to increase the efficiency of heat transfer:

• Radiator equipment thermostatic devices. Thermal heads will maintain the required comfortable temperature in the rooms.
• In addition to radiators, install convectors with directed circulation function. They will create thermal curtains from heated air in the area of ​​the openings.
• Connecting equipment that allows you to program optimal heating modes. Installing chronometric thermostats is effective if there are rooms in the house that are empty for several days, which there is no point in intensively heating.

The costs of purchasing and installing automation will more than pay off within the first heating season.

And finally, it’s worth reconsidering whether the system is too loaded. It is possible that it produces excess heat. And it is likely that without compromising the comfort of household members, it is possible to reduce the temperature in the premises by a couple of degrees.

At first glance - a trifle. But, considering the situation on the scale of at least one month, and even more so the heating season, such a decision can have a beneficial effect on the wallet.

Conclusions and useful video on the topic

One of the options for calculating network gas consumption:

Example of consumption for heating with liquefied gas:

Simple ways to reduce gas costs will be discussed in the following video:

The average calculation value will be useful for calculating material costs solely for heating the building. When planning to use gas appliances or a stove during the heating season, the data should be adjusted.

If, after studying the material, you have questions about calculating gas consumption, you can ask them in the block below.In addition, if any inaccuracies were noticed or you would like to supplement the material, please leave your comments.