How to calculate how much gas a gas boiler consumes

Knowing the amount of gas your gas boiler uses is one of the most important things to know when it comes to effectively managing your home’s heating system. Calculating the consumption of your gas boiler is essential, whether your goal is to save energy costs or just to make sure your heating system is operating as efficiently as possible. You can potentially save money on your energy usage by using this calculation to help you make informed decisions.

Understanding the factors that influence gas boiler consumption is the first step. The amount of gas your boiler uses depends on a number of factors, such as the boiler’s efficiency rating, the size of your home, the quality of the insulation, and your heating preferences. You can estimate your gas usage more accurately by accounting for these factors.

Luckily, gas consumption calculations aren’t very difficult. Your boiler’s gas consumption over a specific time period can be estimated with a few simple measurements and calculations. With this information, you can make changes to your heating consumption, find areas where energy can be saved, and make sure your house stays comfortable all year round.

We’ll guide you through the process of accurately calculating the consumption of your gas boiler in this article. This guide will give you the information you need, whether your goal is to maximize the efficiency of your heating system, lower your energy costs, or just have a better understanding of how much energy your home uses.

Calculating how much gas a gas boiler consumes per hour, day and month

The entire area of the home and the heating equipment’s capacity are the two primary indicators used in the design of private home heating systems. It is assumed in basic average calculations that 1 kW of thermal power plus 15-20% power reserve is sufficient for heating every 10 m 2 area.

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However, if natural gas from the mains is being used, it is more convenient to measure the work directly in cubic meters per hour (cc. m/hour) for cost planning, or in kilograms per hour (kg/hour) if liquefied gas is being used (which is much more expensive).

Given that natural gas has a known calorific value of 9.3–10 kW per m3, a gas boiler producing 1 kW of heat will require roughly 0.1-0.108 m 3 of natural gas. As of this writing, the price of one meter three of main gas in the Moscow area is 5.6 rubles/meter three, or 0.52-0.56 rubles per kilowatt-hour of heat output produced by the boiler.

However, you can still use this method even if you don’t know the boiler passport data because practically all boilers have characteristics that show the gas consumption during continuous operation at maximum capacity.

For instance, the well-known floor-standing Protherm Wolf 16 KSO single-circuit gas boiler (capacity 16 kW), when powered by natural gas, uses 1.9 m 3 per hour.

1. Per day – 24 (hours) * 1.9 (m 3 /hour) = 45.6 m 3 . In value terms – 45.5 (m 3 ) * 5.6 (tariff for the MO, rub.) = 254.8 rubles/day.
2. Per month – 30 (days) * 45,6 (daily consumption, m 3 ) = 1 368 m3. In value terms – 1,368 (cu. м) * 5.6 (tariff, rub.) = 7,660.8 rubles/month.
3. For the heating season (let"s assume, from October 15 to March 31) – 136 (days) * 45,6 (m 3 ) = 6 201,6 cubic meters. In value terms – 6 201,6 * 5,6 = 34 728,9 rubles/season.

These are merely rough theoretical calculations, though, as the boiler does not operate at maximum efficiency around-the-clock in real life, which accelerates the deterioration of its components many times over. A gas boiler that is skillfully chosen based on capacity (considering factors such as the house’s area, heat loss, and a modest power reserve of 10–20%) uses only 50–70% of the values computed above for the boiler’s maximum possible mode of operation.

In actuality, the same Protherm Wolf 16 KSO uses between 700 and 950 cubic meters of gas per month, or roughly 3,920 and 5,320 rubles, depending on the circumstances and heating mode. It is impossible to calculate the precise amount of gas consumed!

Use metering devices (gas meters) to obtain precise values, as the amount of gas consumed by gas heating boilers varies depending on a number of unique factors for each private home, including the owner’s preferred temperature, the configuration of the heating system, the average temperature in the area during the heating season, and many others.

Table of consumption of known models of boilers, according to their passport data

Calculator for quick calculation

Remember that the calculator applies the same principles as the example above; the actual data consumption may only be 1.0 kg/hour of liquefied gas, 50–80% less than the data calculated assuming that the boiler operates continuously and at full capacity, depending on the model and operating conditions of the heating equipment.

Additional theoretical ways of calculating natural gas consumption

Based on the heat loss of the house

The area of the glazing plus any adjustments made to it, the house’s insulation level, the climate zone, and the temperature during the coldest decade of the heating season are used to calculate the precise amount of heat loss from the building. Simple assumptions state that there is 1-1.2 kWh of heat loss for every 10 m 2 of an average home with two bricks of masonry and a ceiling as high as 2.7 m. Therefore, it’s important to create a balance between the heat lost from the heating system and the heat that the heating system generates in order to maintain a comfortable temperature.

Using an average 100 m 2 house in the Moscow area as an example, let’s calculate without making any assumptions about climate zone adjustments. About 11 kWh will be lost in heat in this kind of house, and the gas boiler will generate the same amount. Recall that natural gas combustion has a specific heat capacity of 9.3 kW. But since 90% of gas boilers are efficient, one needs to factor in a suitable efficiency allowance.

Overall gas consumption is calculated as follows: 1.31 m 3 /hour = 11. (kW / hour) / (9.3 (kW) * 0.9 (efficiency 90%)) = 31.44 cubic meters per day. The tariff for the Moscow region is 176.1 rubles per day as of the time this article was written.

However, similar to other approaches, the heat loss calculation provides an approximative image with 10–30% deviations in each direction. The flow rate may be very low in the warmest month of the season, but the boiler will run at maximum capacity with open burners all the time in the coldest decade because of high heat losses.

Boiler consumption of a certain output

Some people calculate gas consumption based on boiler output, which makes sense in situations where the boiler unit is old and the passport flow rate is uncertain. Assuming a boiler with a 10 kW capacity, calculations will also require the boiler’s efficiency, which is most likely unknown. However, in reality, the efficiency of older Soviet and post-Soviet gas boilers was hardly higher than 70%.

The concept of boiler consumption is determined by the previously established examples: 10 kW / (9.3 kW * 0.7 (assumed efficiency of 70%)) = 1.54 cu. m/hour or 36.96 cu. m/day when the primary burners are running continuously. A 24 kW boiler will use 24 / (9.3 * 0.7) = 3.69 cubic meters of gas per hour.

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It’s critical to comprehend how much gas your boiler uses in order to efficiently heat your house and control your energy expenses. You may more effectively budget for your energy costs and make sure your house stays warm and cozy without going over budget by figuring out how much your gas boiler uses. There are a few easy steps involved in this calculation: finding the boiler’s efficiency rating, ascertaining the heat output, and taking your home’s insulation and heating requirements into account. By using this information, you can more precisely estimate how much gas you use, which will ultimately save you money and energy.

Consumption of gas boiler on liquefied gas

Both natural and liquefied (cylinder) gas can be used in a lot of gas boilers, both contemporary and vintage. Changing the fuel simply requires replacing the burner, which is typically located in the set, and connecting the gas cylinder. Any of the aforementioned principles can be used to calculate the flow rate, including heat losses, boiler unit capacity, and passport data on flow rate when working with liquefied gas.

It is incorrect to measure liquefied gas consumption in milliliters or m-3; instead, it makes more sense and is more convenient to indicate the volume in kilograms when discussing boiler equipment.

For instance, the Rinnai BR-K12 gas wall-mounted boiler uses 1.0 kg of liquefied gas per hour when operating continuously at maximum power. As of this writing, liquefied gas costs 33 rubles per kilogram.

1. per day – 24 (hours) * 1.0 (kg/hour) = 24 kg. In value terms – 24 (kg) * 33 (cost of 1 kg, rub.) = 792 rubles/day.
2. In a month burns – 30 (days) * 24 (daily consumption, kg) = 720 kg. In value terms – 720 (kg) * 33 (price, rub.) = 23 760 rubles/month.
3. During the heating season (let"s assume from October 15 to March 31) – 136 (days) * 24 (kg) = 3,264 kg. In cost terms – 3 264 * 33 = 107 712 rubles/season.

When utilizing liquefied gas, the cost of heating becomes simply "golden" despite the reduced consumption, not accounting for the extra concerns regarding the purchase, transportation, and connection of the fuel supply.

To effectively manage your energy bills, you must calculate the amount of gas your gas boiler uses. You can find possible energy-saving opportunities and make well-informed decisions about your heating system by knowing how to calculate gas consumption.

Determine your boiler’s gas consumption rate first. Usually, the manufacturer’s website or the boiler’s handbook contain information on this. Usually, the measurement of the consumption rate is expressed in cubic feet or cubic meters per hour.

You can compute your boiler’s daily, weekly, monthly, or annual gas consumption once you know the consumption rate. To find the consumption rate, just multiply it by the total number of hours the boiler runs in a given week, month, or year.

Remember that your gas consumption can also be influenced by other factors, like the size of your home, the amount of insulation in it, the efficiency of your boiler, and your heating habits. Maintaining your boiler on a regular basis can also lower gas consumption and increase efficiency.

You can lower your energy bills and lessen your carbon footprint by keeping an eye on your gas consumption and putting energy-saving measures in place, like upgrading to a more efficient boiler or changing your heating habits.

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