Gas consumption for heating a house of 100 m²

The nominal gas consumption for heating a house is 100 m², for a month or for the entire heating period, if the system has already been installed and has been in operation for a long time, it is quite simple to calculate - it will be enough to take meter readings at the beginning and at the end of the month during the year, sum them up, and then calculate arithmetic mean parameter. Another thing is if you need to know this data at the stage of drawing up a house project in order to make a choice of an economical and efficient energy source and appropriate heating equipment.

Therefore, the question of how to correctly determine the weighted average gas consumption for heating a building of a given area is so important. There are several options for such calculations.

The procedure for carrying out calculations for heating with network gas supply

Natural gas supplied to consumers through engineering networks is by far the most optimal energy carrier for organizing a heating system for private housing. This is due to the low price of fuel, the absence of the need to create its reserves, and the rather high efficiency of modern gas equipment.

Naturally, when choosing a gas boiler for heating a house, it is necessary to focus on its power, since not only the efficiency of the entire heating system, but also the energy consumption will depend on it. However, gas consumption is affected not only, and not so much by the power of the boiler, but by many other factors that should also be taken into account. These include the climatic conditions of the region of residence, the design features of the building itself, the area and height of the ceilings of heated rooms, the quality of insulation of building structures, the number and type of windows, and other important parameters.

It should be understood that the nameplate power of the boiler shows its maximum capabilities, which, of course, must be higher than the required characteristics. So, for example, after making calculations in the required heat output for heating a house, the optimal model of the heater is always selected with higher rates. For example, if as a result of calculations it is obtained that the heating system requires 12-13 kW, then the owner will most likely select a boiler with a power of about 15-16 kW.

All this is being said now in order to make it clear: it would be erroneous in the preliminary calculation of gas consumption for heating and planned costs to rely only on the characteristics indicated in the technical documentation of the boiler. The list of product parameters usually contains gas consumption (m³ / h), but this, again, is to achieve the power declared by the manufacturer. If we take these indicators as a basis, then the total results may seem daunting!

But it is necessary to correctly calculate at least an approximate gas consumption not only in order to make sure that it is the most economical fuel, but also to determine what measures can be taken to reduce consumption, and hence reduce regular payments for it.

The main indicator from which you need to start the calculations is, rather, not the declared power of the heating device, which is still unlikely to be used "to its fullest", but the necessary thermal power for high-quality heating of the house and replenishing its heat losses.

Very often, the ratio of 1 kW of thermal energy per 10 m² of heated space is taken as the basis for such heat engineering calculations. This approach, of course, is very convenient for calculations, but still does not fully reflect the real conditions of a particular house and region of residence.

It is better to make a more thorough calculation, taking into account the main factors affecting the required thermal power. It is quite easy to do this if you use the method proposed on our portal.

How to independently calculate the required thermal power?

An accessible methodology for conducting independent calculations is given in the publication of the portal dedicated to.

The value obtained as a result of the calculations will become the “starting point” for determining the average gas consumption for heating.

Further calculations will require a formula that takes into account the energy potential embedded in the "blue fuel", that is, the amount of heat that is released during the combustion of one cubic meter of gas.

V = Q / (Ni × ηi)

Let's decipher the notation:

V- the desired value, that is, the gas flow to obtain a certain amount of thermal energy, m³ / h.
Q- the required thermal power, W / h, to ensure comfortable conditions in the premises.

How to calculate it - already decided. But again, an important remark needs to be made. As can be seen from the calculation conditions, the obtained value will be the maximum calculated for the most unfavorable conditions of the coldest decade of the year. In reality, there will not be so many such periods during the entire heating season, and even a boiler with a well-planned heating system never works constantly. And since our goal is to determine exactly the average, and not the peak gas consumption, it will not be a big mistake to take the average value of the generated power as 50% of the calculated one. Again, not to be confused with the nameplate capacity of the heating boiler.

Hi- specific lower calorific value of gas combustion. This is a calculated tabular value that complies with existing standards. So, for network gas, it is taken equal to:

Pay attention to the type of gas. Most often, G20 is used in household networks. But the gas of the same second group can also be used, but already of the G25 type, which is characterized by a high nitrogen content. Naturally, its energy potential is less. If you do not know what type is used in your network, it is easy to check with the regional gas supply organization.

One more nuance. There is one more value in the table - hs. This is the so-called higher value of the calorific value of gas. The point is that the water vapor formed during the combustion of gas also has latent thermal energy, and if it is used, then the overall return on fuel naturally increases. It is this principle that is applied in a new generation of boilers - condensing, in which, due to the transfer of steam to a liquid state of aggregation, another 10% of heat is taken. That is, the indicated indicator can be taken as a basis for calculations for heating systems with boilers of this type.

The specific heat of combustion is indicated in joules, but for the correct calculation it must be converted to watts. The ratio is as follows:

1 kW = 3.6 MJ

In our case it turns out:

ηi- the efficiency of the boiler, that is, a value showing how efficiently in a particular model the thermal energy obtained from gas combustion is spent precisely on heating the coolant.

This is the passport value of the product. In modern models of boilers, it can also be indicated by two values \u200b\u200b- according to the highest and lowest calorific value of gas, through a fraction sign: Hs / Hi, for example, 92.3 / 84%. Naturally, you can choose a value corresponding to the actual operating modes of the boiler. But, as a rule, for a reliable calculation, “without embellishing” the capabilities of the equipment, the value for the Hi mode should be taken.

So, all the data for the calculation are known - and you can proceed to practical calculations. Let's look at an example:

Suppose it was calculated that 9.4 kW of thermal energy is needed to effectively heat a particular house of 100 m². Network gas - G20. Boiler efficiency - 0.88. It is required to determine the average gas consumption for heating.

As already mentioned, to determine the average flow rate, the required thermal power can be divided by two, that is, we take for calculations 9.4 / 2 = 4.7 kW

V = 4.7 / (9.45 × 0.88) = 0.565 m³/h

For a day, on average, it is spent - 0.565 × 24 = 13.56 m³;
Monthly average - 13.56 × 30.5 = 413.71 m³;
The heating period in different regions may differ in its duration. But, for example, take 7 months:

413.71 × 7 = 2896 m³

Knowing the price of one cubic meter of gas, you can roughly plan your "accounting" for the upcoming heating season.

Once again, it should be emphasized that the resulting value of consumption per hour is a very average. Of course, at the peak of winter frosts it will be higher, but then it will “recoup” in the autumn or spring months, during thaws or during periods of stable weather normal for the region.

To simplify the task for the reader, we will place a calculator that will help determine the average hourly, daily and monthly consumption of natural gas. The total costs will then be easy to calculate, given the approximate duration of the heating season in the region and the level of prices for "blue fuel".

Calculator for calculating the average consumption of network gas for heating needs

Enter the full value of the calculated heat output for the heating system (kW)

half

Specify the type of pipeline natural gas used

Specify boiler type

Specify the passport value of the boiler efficiency η (if two values are indicated in the passport, then it is selected for the Hi mode)

Calculation of the consumption of liquefied gas

It is convenient and profitable to use gas supplied through a centralized gas pipeline. However, such a possibility does not always exist, since, unfortunately, gas pipelines are not laid in all settlements, or they run far enough from the built house, and the owners do not have the financial ability to pay for the connection. Therefore, some homeowners use liquefied gas, brought and stored in cylinders or in gas tanks, which are filled with special delivery services for this fuel.

Gas holders are tanks designed to store gaseous substances, including liquefied gas, in large quantities. These tanks are usually installed in pits specially prepared for them and buried in the ground, only the manhole cover remains on the surface, through which the tank is filled with gas.

Storage for liquefied gas - gas tank

If liquefied gas from cylinders is used, then several containers with fuel can be connected to the house wiring at once.

Carrying out calculations, in principle, is similar to what was described above, but there are some differences. They mainly relate to the aggregate state of the fuel, since the consumption in this case will be expressed in kilograms or liters.

To calculate the consumption of liquefied hydrocarbon gas, it is necessary to know some of its significant physical characteristics:

The density of fuel type G30 (propane-butane mixture SPBT) is 0.524 kg/l.
The specific heat of combustion is assumed to be 45.2 MJ/kg.

Gas cylinders used in domestic conditions can have a different volume, but, basically, containers of 50 liters are used for heating. In order to comply with safety requirements, they are usually only filled to 80÷85%, that is, each cylinder can hold about 40÷42.5 liters of liquefied gas.

It turns out that with liters the calculation will be somewhat clearer, so you should bring the value of the specific heat of combustion to liters.

We get 23.68 MJ/liter.

We translate into the watts we need:

23.68 / 3.6 = 6.58 kW/l

So, in order to calculate the consumption of liquefied gas for heating per 100 sq. m. of the area of the house, for the same example as given above (average power of 4.7 kW, efficiency of the heating boiler - 0.88), we will use the already known formula, but with the values \u200b\u200balready reduced to liters:

V = Q / (Нi × ηi)

V = 4.7 / (6.58 × 0.88) = 0.81 l/h

Average daily consumption:

0.81 × 24 = 19.48

This value suggests that one cylinder with a filling of 42 liters. will be enough for heating purposes for a little more than two days (approximately 52 hours), but without taking into account the possible use of gas for other needs, such as cooking.

The monthly heating bill will be:

19.48 × 30.5 = 594.16 liters., that is, a little more 14 filled cylinders.

For seven months of the heating season, the total consumption can be:

594.16 × 7 = 4160 liters of liquefied gas, or almost 100 standard 50-liter cylinders with normal filling.

This is, of course, a fairly large amount of fuel, and it will cost a lot, especially considering transportation costs and the need for proper organization of storage. However, this approach is more preferable and economical than electric heating or using solid or liquid fuel boiler equipment.

To calculate the consumption of liquefied gas, a special calculator is also available:

Calculator for calculating the consumption of liquefied gas for heating needs

Enter the requested values and click the "CALCULATE" button

The key to the efficiency of the heating system is high-quality insulation of all elements of the house

In this diagram, you can clearly see how heat can flow out of the house. Thus, an uninsulated floor, as well as entrance doors, let in up to 14÷15%, walls 23÷25%, a roof 13%, and windows with low-quality frames - even up to 30÷35% of the heat generated by the boiler. It is often said figuratively about this process that the street has to be heated. The greater the heat loss, the more funds paid for heating will be wasted.

In order to reduce these costs, it seems expedient to invest once in high-quality thermal insulation at home, which will certainly pay off all the costs for it in a few years. To do this, it is necessary to think over and organize the insulation of floors, walls, attic floors and, preferably, roofs, as well as replace windows and doors with modern models that provide high energy saving.

Wall insulation

Whatever material is used for the construction of walls, up to 25% of heat escapes through them. Therefore, they require mandatory insulation. Nowadays, there is a considerable amount of materials for thermal insulation of enclosing structures, and there should be no problems with the choice.

Among the most affordable and easy to install is expanded polystyrene, which is most often used for these purposes. Expanded polystyrene panels are produced in various thicknesses, and they are selected according to this parameter, depending on the thickness of the external walls of the house and the material from which they were built.

Another fairly popular heat insulator, especially for insulating wooden houses, is mineral wool, which is also easy to attach to walls, and it gives an excellent insulating effect. True, the price of this material is slightly higher than for ordinary foam.

Any of the heaters is closed from the outside with a finishing material. For this purpose, decorative lining, siding, other types of facade panels are used, or thermal insulation is finished with a reinforced plaster layer using the “wet facade” technology.

How to insulate the walls of a wooden house?

One of the options is the use of high-quality mineral wool with further finishing according to the principle of a ventilated facade. - detailed in a separate publication of our portal.

Attic and roof insulation

Heated air from heat exchange devices (radiators, convectors) rises, and if the ceiling does not have sufficient thermal insulation, it quickly cools down, contacting the cold ceiling, wasting precious energy on unnecessary heating of the floor. Therefore, the attic floor requires good insulation.

For this purpose, different materials are used, which can be mounted both from the inside and from above, between the floor beams. It can be the same expanded polystyrene or mineral wool or ecowool, sawdust or shavings, etc.

Sprayed polyurethane foam shows an excellent insulating effect, which can also be used to insulate roof slopes. The only problem with its use may be that its spraying requires special equipment and certain work skills, so you will have to invite a team of specialists.

The remaining heat-insulating materials may well be used independently, since their installation does not involve any impracticable technological operations.

Roof insulation is an important condition for a comfortable microclimate in a private house

Floor insulation

For example, to insulate wooden floors, dry backfills (expanded clay), mineral wool or expanded polystyrene slabs are used, which are placed between the logs under the finish coating.

The same materials, subject to certain technological rules, can also be laid on a concrete base, followed by pouring the screed.

Both wood and concrete flooring can serve as the basis for the installation of a "warm floor" system.

Floor insulation with polystyrene foam

One option for thermal insulation of the floor is the use of expanded polystyrene panels. The information posted in a special article of our portal will help to carry out on your own.

window replacement

An important point in preserving heat inside the house and reducing fuel consumption is the replacement of old windows, since it is through them that the most significant heat losses occur.

The best option, which will become a reliable shield between indoor heat and winter cold, will be modern PVC windows with high-quality double-glazed windows of one type or another. Such models almost hermetically cover the window opening and protect the house not only from heat loss, but also from street noise.

Other ways to reduce fuel consumption

In addition to high-quality insulation of building elements, other possibilities that may affect the reduction of fuel consumption should be considered.

Among them are the following:

Installation of convectors with directional circulation of heated air, in addition to heating from radiators. Convector devices are able to create thermal curtains for windows and doors that will not allow cold air to enter the premises.
Installation of modern equipment with the ability to program optimal heating modes for individual rooms of the house and for time. Some rooms are empty at certain times of the day or even days of the week, and it makes no sense to intensively heat the room when there is no one in it.
Heating radiators in each of the rooms must be optimally placed and connected in order to increase the efficiency of their heat output. It is advisable to equip them with thermostatic devices that will allow you to maintain the desired temperature in the room.

In order for the heat from the radiator to be directed into the room and not go into the wall, it is recommended to fix a foil insulation material behind each battery, which will act as a reflective screen.

What is important to know about heating radiators?

The efficiency of the heating system is affected by the type of radiators, and the correct installation in the premises of the house. A lot of useful information on these issues can be gleaned from the article on our portal dedicated to the room.

Finally, it is necessary to carefully consider whether the heating system is being loaded too much to create excess heat. Experiment - it is possible that the rooms are too hot, and that without showing any kind of discomfort, it is quite possible to reduce the temperature by 2 - 3 degrees. It seems, at first glance, a trifle, but on the scale of even one month, not to mention the entire heating season, it can bring quite tangible savings.

Sometimes it is not superfluous to think soberly - is it not too hot in the house?

As you can see from the examples and formulas for gas consumption for heating, it is quite possible to carry out the calculation on your own and on your own, since this process is not a particularly difficult task. It is enough to allocate some free time, use the proposed method - and get the result. And he, in turn, should be a reason to think about improving the energy efficiency of your own home.

At the end of the publication - an interesting video information with tips on consumption calculations and measures for possible gas savings.

Video: gas consumption for heating and available measures to reduce it

author Nikolai Strelkovskiy, editor-in-chief