How much gas does a gas stove consume: how to calculate gas consumption

Before you buy gas appliances, you can find out its efficiency using your calculator.Read about stove efficiency and calculate how much gas a gas stove consumes at standard settings. Agree, it’s better to figure it out one day, rather than read articles one after another. Our article will be extremely useful for you.

There is nothing complicated in physical formulas if you understand the essence of the issue. We will teach you this. Based on the formulas, they determine how much fuel the device uses per hour of active operation and how well it works in general. We will reveal the technical side of the issue. At the everyday level, you will decide for yourself what needs to be done.

Gas stoves have different fuel consumption for the same operation. Sometimes burners with a double difference in power give the same effect. The stoves have burners on the hob, and some models are also equipped with gas ovens. In this article we have collected information about the power of burners and gas stoves that you should pay attention to.

Methodology for calculating gas consumption

Consumption is calculated based on the total power of all burners gas stove and its different functions. Calculation can be useful when searching for new equipment, because the difference in fuel consumption between two models reaches 2-3 times.

Electric stoves cannot displace gas stoves from the market, and the latter have more and more new features: touch panels, voice control, ignition protection

The power of the burners (burners) is indicated in the passport for the stove, and it will be issued upon request.In order not to solve the problem of excessive gas consumption, products without a passport should be avoided.

Household gas stoves have from 2 to 6 burners on the hob and 1-2 in the oven, if it also runs on gas. Based on their performance, burners are divided into powerful - large, regular - medium and burners with reduced productivity - small. The higher the power, the more fuel the burner consumes. In the instructions for different stoves, the concepts of power level do not coincide.

Average parameters for burners:

• power 1 auxiliary (small) burner or the so-called burner productivity during auxiliary operation - up to 0.6-1 kW;
• power 1 semi-fast (medium) burner - approximately 1.1-2.1 kW, sometimes - no less than 1.6 kW;
• power 1 fast (large) burner - approximately 2.1-3.1 kW;
• power 1 oven burner - more than 3 kW for one and from 2 kW for each, if there are two of them.

The total power involved depends on the number of burners lit, the size of the flame and the use of additional options. Usually it is at least 5.5 kW when using all burners of the hob and oven simultaneously.

Useful functions, including oven lighting, consume only 15-25 watts. Classic stove has 4 burners and all are on the hob: 2 normal performance and 1 each - high and low.

Built-in gas hob: the cost starts from only 3,500 rubles for a 2-burner and 4,500 for a 4-burner, and its models differ significantly in burner power

The maximum gas consumption of the stove is determined by the formula Vhour = Q / (q × efficiency / 100%), Where:

• Vhour — maximum gas consumption for one hour, m³/hour;
• Q (also denoted as N, P, S) - the sum of power indicators for each burner, conventionally - the power of the stove, kW;
• Efficiency (efficiency) - positive action coefficient, %;
• q — calorific value (specific heat of combustion) of fuel, kW·h/m³.

Calculating the maximum power will not cause any difficulties, but it will not be possible to determine the approximate monthly consumption for comparison with the standard or meter indicator. Depending on how much fuel a gas stove consumes and how many kilowatts an electric kettle produces, for example, you can compare the costs of heating water.

The power of the burners is determined according to the passport. The calorific value is taken as the average for a particular type of gas that the stove consumes. It will not be possible to calculate the unknown efficiency before purchasing a stove.

How to determine the efficiency of a gas stove?

It will not be possible to find out the efficiency of a gas stove that is not working, and the basic indicator is 45% - halfway between the minimum of 30 and the limit of 60%. For electrical appliances, the coefficient reaches 70-90%.

The efficiency of a gas stove is expressed as a weighted average of the coefficients for each burner. For individual burners it is 28, 29, 30, 31%, etc. up to just over 60%. Typically, the more powerful the burner, the higher its efficiency, if we talk about the same stove.

Low-flow screw for the burner tap, which “turns on” when you use the stove in low flame mode - it won’t hurt to buy a set of such screws

For comparison, the efficiency of a gas boiler is on average about 90%, but the calculated power would have to be overestimated due to heat loss from the home. In a room with 2 windows and 2 external walls - by as much as 30%.

The exact efficiency of the slab is calculated using the formula:

ƞ = (heating Q / combustion Q) × 100% = (c × m × ΔT / q × ρ × V) × 100%,

wherein

• ƞ — actually, efficiency, %;
• Q - heat (energy). This value is not needed in the calculation;
• c — specific heat capacity of water, 4183 J/kg °C (also 4183 J/kg K);
• m — mass of water heated in the kettle, kg;
• ΔT — the difference between the boiling point (+100 °C) and the initial temperature of water, °C. Usually it is 73-79 °C;
• q — calorific value of pipeline gas, usually 33.50 MJ/m³. With a conversion of 33,500,000 J/m³;
• ρ — density of pipeline gas, kg/m³. We are talking about a corridor of 0.68-0.85 kg/m³. A value of 0.8 kg/m³ should be taken if any other value is unknown;
• V — volume of gas consumed during heating of water to boiling, m³. The calculation uses the difference in gas meter readings - before and after. If there is no separate flow meter for the stove, then before heating the water, you will have to turn off the remaining gas appliances.

For ease of calculation, the specific heat capacity is substituted with the same temperature unit as in the difference for heating water. Take only °C or K, and in both cases the value is 4183.

The low efficiency of the stove can be compensated for with bottled gas with a higher calorific value, but in addition to the container itself, you will also need a reducer and a hose

To accurately assess the effectiveness, the pan for heating water should be closed with a lid.

Calculation of the calorific value of the fuel used

There are higher and lower calorific values. The parameters are determined by the highest (Qv) and lower (Qn) heat (energy) of combustion.

To calculate the actual calorific value, use the formula q = Q / m,

Where:

• q — specific heat of combustion (calorific value), MJ/kg (kW h/kg, kcal/kg);
• Q — calorific value — the amount of heat released during fuel combustion, MJ (kW h, kcal);
• m — fuel mass, kg.

We substitute the indicator Qв or Qн instead of Q and get the highest and lowest calorific value, respectively. The final result corresponds to the measures MJ/kg, kWh/kg and kcal/kg (specific calorie content).

In the case of natural gas, “kg” is replaced by “m³”. Knowing the density, you can determine the number of cubic meters per kilogram. Let’s take the parameter 0.8 kg/m³ for this. We multiply the value in kWh/kg by 0.8 and get the value in kWh/m³. It should be remembered that 1 MJ = 0.278 kWh = 239 kcal.

The specific heat of combustion of natural gas varies between 8 and 11 kWh/m³. Usually it is 9.2-9.3 kW h/m³ - this value is substituted into the very first formula.

For calculations with burner power in kilowatts, the indicated number is taken, and for data with MJ and kcal, the equivalents are used: 33.50 MJ/m³ and 8000 kcal/m³. The values ​​are valid for supplied methane G20 (natural gas), with a nominal pressure of up to 20 mbar. The calorific value reaches 50 MJ/m³ for ordinary methane and 41–49 MJ/m³ for natural gas in the ground.

Some stoves can operate at different pressures and types of fuel, for which they buy the appropriate nozzles; in the photo - nozzles for liquefied gas

The calorific value is taken from the fuel used - natural gas G20 from the pipeline (methane-based mixture), but the stoves also operate from cylinders. Liquefied gas consumption in tables is often measured in kilograms rather than cubic meters, but equivalents can be used for calculations.

Liquefied gas is 1.35 in “natural”.Methane, propane and ethylene in determining the specific heat of combustion have coefficients of 1.494, 1.361 and 1.434.

Nuances in calculating gas volume

The maximum gas consumption per hour shows the consumption of a gas stove in which each burner was operating at full power for 60 minutes in a row. In a day, a stove used by 4 people uses on average about 0.5 cubic meters.

Per month it usually turns out to be more than 3 and less than 4 m³ per person. In bills for apartments without gas meters, the indicators for the stove “grow” 3-4 times. This is all due to the fact that consumption standards are adjusted to suit those who use large volumes of gas.

There are different standard sizes of meters for different maximum gas consumption. The most powerful stoves with an efficiency approaching 30% burn up to 2.5-3 m³ per hour or more when operating continuously at “full speed”. For them it is better to buy a G2.5 meter. For two powerful stoves, a G2.5 or G4 gas meter is enough. Flow meters G1.6 are suitable for small ones.

The G2.5 meter is ideal for a large or powerful stove; for a small stove, G1.6 is enough, and meters starting from G6 will not be able to “catch” the lower limit of the gas consumption of the stove

Household gas meters and their ranges

It wouldn’t hurt to have separate ones for the stove and boiler. counters. It will be more convenient to navigate and make calculations, and the accuracy of gas meter readings will increase.

Example of calculating gas consumption

Let's consider the consumption of blue fuel by the stove Gefest PG 6500-03 0045. The device has 4 burners on the work surface and a gas oven.

Burner power in kilowatts:

• front right - 3.0;
• front left - 1.75-1.8;
• rear right - 1.0;
• rear left - 1.75-1.8;
• oven burner - 3.1;
• grill burner - 1.9.

First, we round up the productivity of medium-power burners to 1.8 kW. Let's sum up the productivity of all six burners: 3.0 + 1.8 + 1.0 + 1.8 + 3.1 + 1.9. We get 12.6 kW.

We take the efficiency at 45%. We select the specific heat of combustion of household gas for two different cases: normal - 9.3 kW·h/m³ and maximum - 11 kW·h/m³. In the first calculation we will use the standard one.

The image shows a Gefest PG 6500-03 0045 stove, designed for a nominal pressure of 13, 20 and 30 mbar, and with a useful oven volume of 52 liters

We use the formula Q / (q × efficiency / 100%) = Vhour. We get 12.6 kW / (9.3 kW·h/m³ × 45% / 100%) = 3.01 m³/h.

For complete clarity of the calculation, we will do it in 3 stages: 12.6 kW / (9.3 kW h / m³ × 45% / 100%) = 12.6 m³ / (9.3 hour × 0.45) = 12, 6 m³ / 4.185 hour = 3.01 m³/hour.

Calculation in steps and only with numbers:

1. 12,6 / (9,3 × 45 / 100).
2. 12,6 / (9,3 × 0,45).
3. 12,6 / 4,185.
4. 3,01.

Gefest PG 6500-03 0045 is not the most efficient stove, but it has 2 burners in the oven, which is why the maximum consumption is so high.

The Hi-Light electric stove burner consumes the same amount as the average Gefest PG 6500-03 0045 burner, but heats up in just 5 seconds and has high efficiency

Let's calculate fuel consumption with maximum specific heat of combustion (11 kW·h/m³):

12.6 kW / (11 kWh/m³ × 45% / 100%) = 2.55 m³/hour.

To make calculations, it is enough to have burner power indicators and know the average values ​​​​for other parameters.

As you can see, there is nothing complicated about calculating the gas consumption of a stove. You just need to devote a little time to this.

We also suggest reading our other article, where we talked in detail about how calculate gas consumption for heating Houses.

Conclusions and useful video on the topic

A clear example of calculating the cost of heating water with devices of different types:

A way to reduce gas consumption and save time on cleaning the hob:

Gas consumption and the total power of the burners have a directly proportional relationship. If we imagine that the parameters for calculating consumption are equal to the average, it will be enough to find out the performance of the burners, and it will become clear how much they save gas.

You cannot do without calculations using the formula if you know the exact efficiency of the model or are going to determine it. After power, this is the second most important indicator in terms of costs. Stovetops with a hob and gas oven have higher fuel consumption, but a gas stove can be better at cooking quality than a high-efficiency electric stove.

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