Propane consumption for home heating 200m2. Calculation of gas consumption for home heating

Gas is still the cheapest type of fuel, but the cost of connection is sometimes very high, so many people want to first assess how economically justified such costs are. To do this, you need to know the gas consumption for heating, then it will be possible to estimate the total cost and compare it with other types of fuel.

Method of calculation for natural gas

The approximate gas consumption for heating is calculated based on half the capacity of the installed boiler. The thing is that at the lowest temperature is laid. This is understandable - even when it is very cold outside, the house should be warm.

But it is completely wrong to calculate the gas consumption for heating according to this maximum figure - after all, in general, the temperature is much higher, which means that much less fuel is burned. Therefore, it is customary to consider the average fuel consumption for heating - about 50% of the heat loss or boiler power.

We calculate the gas consumption by heat loss

If there is no boiler yet, and you estimate the cost of heating in different ways, you can calculate from the total heat loss of the building. They are most likely familiar to you. The methodology here is as follows: they take 50% of the total heat loss, add 10% to provide hot water supply and 10% to heat outflow during ventilation. As a result, we get the average consumption in kilowatts per hour.

Next, you can find out the fuel consumption per day (multiply by 24 hours), per month (by 30 days), if desired - for the entire heating season (multiply by the number of months during which the heating works). All these figures can be converted into cubic meters (knowing the specific heat of combustion of gas), and then multiply cubic meters by the price of gas and, thus, find out the cost of heating.

The name of the crowd	Unit	Specific heat of combustion in kcal	Specific heating value in kW	Specific calorific value in MJ
Natural gas	1 m 3	8000 kcal	9.2 kW	33.5 MJ
Liquefied gas	1 kg	10800 kcal	12.5 kW	45.2 MJ
Hard coal (W=10%)	1 kg	6450 kcal	7.5 kW	27 MJ
wood pellet	1 kg	4100 kcal	4.7 kW	17.17 MJ
Dried wood (W=20%)	1 kg	3400 kcal	3.9 kW	14.24 MJ

Heat loss calculation example

Let the heat loss of the house be 16 kW / h. Let's start counting:

Convert to cubic meters. If we use natural gas, we divide the gas consumption for heating per hour: 11.2 kW / h / 9.3 kW = 1.2 m3 / h. In calculations, the figure 9.3 kW is the specific heat capacity of natural gas combustion (available in the table).

Since the boiler does not have 100% efficiency, but 88-92%, you will still have to make adjustments for this - add about 10% of the figure obtained. In total, we get the gas consumption for heating per hour - 1.32 cubic meters per hour. You can then calculate:

• consumption per day: 1.32 m3 * 24 hours = 28.8 m3/day
• demand per month: 28.8 m3 / day * 30 days = 864 m3 / month.

The average consumption for the heating season depends on its duration - we multiply it by the number of months that the heating season lasts.

This calculation is approximate. In some month, gas consumption will be much less, in the coldest - more, but on average the figure will be about the same.

Boiler power calculation

Calculations will be a little easier if there is a calculated boiler capacity - all the necessary reserves (for hot water supply and ventilation) are already taken into account. Therefore, we simply take 50% of the calculated capacity and then calculate the consumption per day, month, per season.

For example, the design capacity of the boiler is 24 kW. To calculate the gas consumption for heating, we take half: 12 k / W. This will be the average need for heat per hour. To determine the fuel consumption per hour, we divide by the calorific value, we get 12 kW / h / 9.3 k / W = 1.3 m3. Further, everything is considered as in the example above:

Next, we add 10% for the imperfection of the boiler, we get that for this case the flow rate will be slightly more than 1000 cubic meters per month (1029.3 cubic meters). As you can see, in this case everything is even simpler - fewer numbers, but the principle is the same.

By quadrature

Even more approximate calculations can be obtained by the quadrature of the house. There are two ways:

Each owner can evaluate the degree of insulation of his house, respectively, you can estimate what gas consumption will be in this case. For example, for a house of 100 sq. m. with average insulation, 400-500 cubic meters of gas will be required for heating, 600-750 cubic meters per month for a house of 150 square meters, 800-100 cubic meters of blue fuel for heating a house of 200 m2. All this is very approximate, but the figures are based on many factual data.

Calculation of the consumption of liquefied gas

Many boilers can run on LPG. How beneficial is it? What will be the consumption of liquefied gas for heating? All this can also be calculated. The technique is the same: you need to know either heat loss or boiler power. Next, we translate the required amount into liters (units of measurement of liquefied gas), and if desired, we consider the number of required cylinders.

Let's look at the calculation with an example. Let the boiler power be 18 kW, respectively, the average heat demand is 9 kW / h. When burning 1 kg of liquefied gas, we get 12.5 kW of heat. So, to get 9 kW, you need 0.72 kg (9 kW / 12.5 kW = 0.72 kg).

• per day: 0.72 kg * 24 hours = 17.28 kg;
• per month 17.28 kg * 30 days = 518.4 kg.

Let's add a correction for the efficiency of the boiler. It is necessary to look in each specific case, but let's take 90%, that is, add another 10%, it turns out that the monthly consumption will be 570.24 kg.

Liquefied gas is one of the heating options

In total, this boiler will require 27 cylinders of liquefied gas. And consider the cost yourself - prices vary by region. But don't forget about shipping costs. By the way, they can be reduced if you make a gas tank - a sealed container for storing liquefied gas, which can be refueled once a month or less - depending on the storage volume and needs.

And again, do not forget that this is only an approximate figure. In cold months, gas consumption for heating will be more, in warm months - much less.

• 1 liter of liquefied gas weighs approximately 0.55 kg and, when burned, gives approximately 6500 kW of heat;
• There are about 42 liters of gas in a 50 liter bottle.

No serious entrepreneur will start a new business without delving into a carefully prepared business plan. This approach should be applied by the owners of country houses when they make decisions on construction, laying communications, on the introduction of one or another life support system in their possessions. One of the most important problems of such a plan is the need to create an efficient and, if possible, minimally costly system for autonomous heating of the building.

Gas heating is by far the most attractive. But if the house is not connected to the gas pipeline network, and in the foreseeable future there are no “progress” in this area, then its owners will have to make an important decision in favor of some other source of energy. Option - use of imported liquefied gas, for which it will be necessary to organize a capacious underground storage - a gas tank.

But Is it profitable to heat a house with liquefied gas? from a gas tank? IN how much will it cost to heat a house within one season? Our post will help you figure this out. Or rather, even - not to figure it out, but to calculate the costs for the future using an online calculator.

How to determine the consumption of liquefied gas?

If you think about it, there is no particular difficulty here. The calorific value (calorific value) of the reduced gas (LNG) of the most common type (propane-butane mixture G30) is known. It is 42.5 MJ/kg. That is, burning a kilogram of LNG releases 42.5 megajoules of heat.

At the household level, we are probably more accustomed to measuring energy in other units, in watts and kilowatts. And it is more convenient to perceive a liquid substance in terms of volume, for example, in liters. It is not difficult to recalculate, knowing the density of LNG and the relationship of fundamental physical quantities - the energy potential of liquefied gas G30 is approximately 6.58 kW / dm³, in other words - per liter.

And how to find out the need of a particular house for thermal energy, so that in winter it maintains a comfortable temperature for all residents? Nothing is impossible either!

The required amount of heat is easy to calculate!

The simplest approach is to take 100 watts for each "square" of area. But this is a very generalizing ratio, which can give considerable errors both in one direction and in the other. It is better to use another algorithm, also supported by a convenient online calculator. You will find this in the publication of our portal.

When calculating gas consumption, the efficiency of the boiler and some other nuances are also taken into account.

The whole calculation is embodied in the calculator below. If there are ambiguities, explanations to the program will help.

conclusions

Now you have an idea of ​​what is the gas consumption for heating a house of a certain area. The above calculation algorithm allows you to calculate this indicator in kilowatts. You can also find out the estimated consumption, focusing on the data from the technical data sheet. Each manufacturer indicates the level of gas consumption by a particular boiler. Knowing these figures based on 1 hour, you can easily calculate the annual budget for "blue fuel" needed to heat a particular house.

As for the recommendations on savings, the most important of them is this - correctly select the equipment specifically for your home. So you can avoid a fatal mistake - buying the wrong heating equipment. It also makes sense to take care of the thermal insulation of your home, the installation of a "warm floor" system, the aggregation of equipment with external sensors, and a host of other opportunities to make gas consumption optimal for comfortable heating of your home.

How to calculate gas consumption for heating a house

Gas heating is one of the most optimal and profitable. By choosing it, there is no need to prepare firewood and briquettes before each winter period. However, before buying a heating gas boiler, you should know approximately what the coolant flow rate will be. The calculated value may depend on many factors:

• Size of living spaces
• Building materials used in the construction of the frame
• Quality of surface insulation (floor, ceilings, walls)
• Heating equipment power

It is necessary to calculate the gas consumption for heating a house not only to compare the economic benefits when using other sources of thermal energy. It will be possible to determine what measures should be taken to reduce energy costs and their profitability.

We make a calculation taking into account the power of the boiler

Gaseous fuels can be propane, butane, methane, hydrogen, as well as traditional natural gas. Natural gas reserves exceed the volumes of oil and coal, so it is important to correctly calculate such an economical energy source used in heating systems, cooking and other household needs, including hot water supply.

Competent self-calculation of the total gas consumption will not require special skills, given the main parameters of the equipment.

To perform independent calculations, you will need to know the power level of the boiler used and the area of ​​\u200b\u200bthe room, as well as use tabular data.

Round-the-clock operation of the unit in a monthly mode involves multiplying the data in order to obtain kilowatt-hours. The choice of the power of the unit is carried out based on the total area of ​​​​home ownership, and when calculating the volume of blue fuel consumed, it is always necessary to focus on the lowest temperature indicators outside the window.

By quadrature

It is important to remember that in order to calculate by quadrature, it is necessary to find the derivative of the equipment power by the number of hours per day and the number of days per week. It is especially important to correctly calculate the energy consumption for heating according to the operating mode and taking into account the use of 1.0 kW for every 10 m² of heated area.

Table: indicators for calculating fuel consumption

For example, for full-fledged, as well as the most efficient heating of a room with a total area of ​​30 m², it is necessary to purchase a boiler with a power of only 3.0 kW. Therefore, to heat one square meter of area, it will be necessary to spend 100 W of thermal energy, taking into account the height of the room up to 300 cm.

V = Q / (q x efficiency / 100), where:

• V - standard indicators of volumetric gas flow per hour for each cubic meter.
• Q - heat losses and power of the heating system in kW.
• q - the lowest indicators of the specific calorific value of the energy carrier in kW / m³.
• Efficiency - indicators of the efficiency of the operated equipment.

For example, to warm up air masses in a room with a total area of ​​90 square meters, V = 9.0 / (9.2 x 96 / 100) = 9.0 / 9.768 = 0.92 m³ / hour is consumed.

Kzap × OP × RT × KR × 1kW / 860 kV, where:

• K zap is a correction value equal to 1.15 or 1.20.
• OP is an indicator of the total volume of the room.
• RT is the temperature difference between indoors and outdoors.
• KR are indicators of the dispersion coefficient.

For example, 1,000 mg of standard fuel is 7,000 kcal, and in other terms - 7 × 10 - 3 Gcal, while ideal under conditions of 1 efficiency are indicators of the specific consumption of a standard unit of fuel to generate 1.0 Gcal of heat.

One of the most common options for calculating the cost of gas for heating a house is to take into account the characteristics of the installed boiler. Before purchasing it, it is recommended not to make a mistake with the power, which can be determined based on the ratio: 1 kW for every 10 squares of heated premises.

If the boiler power is greater, there is nothing to worry about. However, if it is not enough, you should think about buying updated, more modern and productive equipment.

[monthly consumption] = [capacity]*[average number of days in a month]*[hours in a day]

Thus we get: 10 kW * 30 days * 24 hours = 7200 kW / h. It should be noted that the boiler is unlikely to function for a full day, so the resulting value is divided by two - it turns out 3600 kW / h.

[seasonal consumption] = [monthly consumption]*[heating season duration]

In each region, the duration of the heating season can last differently. When making a calculation, it is recommended to take this value equal to seven. Thus, we get 3600 kWh * 7 months. = 25200 kWh.

[heating costs] = [expenditure per season]*[price of 1 kWh]

It remains only to clarify what the cost of one kWh will be during the winter. By multiplying the numbers, it will be possible to approximately determine the material costs of heating for the entire cold period.

Read about the models and technical characteristics of gas double-circuit boilers here

First, from its power. The larger it is, the higher the consumption of gas boilers will be. Moreover, you will not be able to reduce the appetite of a heat-generating device through the use of it. If you purchased a 20 kW gas hearth, then even at a minimum it will consume more than a 10 kW appliance at maximum. Therefore, be careful when choosing the power of heat generating devices.

Secondly, from the temperature "overboard". In this case, the already mentioned power regulator comes into play. After all, at a low temperature in the house, we will try to squeeze the maximum number of calories out of the heating by turning the regulator knob to the maximum. And if in relatively warm (for winter) weather the regulator is set to “one” or “two”, then at 30- or 40-degree frosts it is switched to “five” or even “seven”. And the number of cubic meters of gas passing through the nozzles into the combustion chamber doubles.

Thirdly, from the calorie content of gas. The consumer does not control this value. Therefore, gas distribution companies sometimes play pranks with the composition of "blue" fuel. After all, the same compressed nitrogen pumped into the central pipeline costs 2.5-3 times cheaper than natural gas. Now, fortunately, such fraud schemes are no longer practiced, but gas workers can easily supply “undryed” gas with a high content of water vapor and other impurities into pipes.

Fourthly, from the technical condition of the heat exchanger. Heating of water or coolant in gas appliances occurs in a heat exchanger - a special copper pipeline located either in the combustion chamber or outside its walls. And if the heat exchanger becomes clogged with scale or scale residues from the batteries, then you will have to add power to compensate for the reduced heat transfer. Moreover, a clogged heat exchanger steals cubic meters much more actively than real or mythical dodgers from a gas distribution company.

Fifth, on the number of heating circuits. Almost all modern gas boilers have more than one heating circuit. After all, such heat-generating devices serve not only the wiring of the heating system, but also the line of domestic hot water supply. To do this, a second circuit is mounted in the design of the gas hearth and the throughput at the nozzles is increased, increasing the power. And the more power, the higher the consumption.

The installation of gas boilers is considered the best solution for areas with a gas supply network. Natural gas has many advantages. This is an environmentally friendly product, affordable, has a high heat transfer. But when choosing a boiler, it is important to immediately determine how much gas the unit uses to heat different areas: from 80 m2 to 400 m2.

Factors affecting fuel consumption:

• Gas boiler power;
• The area of ​​the house or apartment;
• Possible heat losses (number of windows and doors, their tightness, wall thickness and other important parameters).

When buying a gas boiler for a long service, it is important to consider all the nuances of choosing a unit. It should be understood in advance how much gas is spent on heating a certain area and volume of the building. Only with a responsible approach can you have an economical benefit from such a purchase.

Gas consumption in boilers directly depends on the power of the heater. The necessary calculation of power is carried out when purchasing heating equipment. In this case, they rely on the size of the heated area. The calculation is carried out individually for each room, taking into account the lowest average annual temperature.

When calculating the power, use the ratio of kilowatts per 10m2 of the room that is heated. Given the temperature differences, only half of the value is needed, and this is only 50 watts per hour. For an area of ​​100m2, 5 kW is enough. Formula for calculating natural gas: A = Q / q * B.

Deciphering the formula:

• A - the required amount of gas for heating;
• Q - boiler power for heating a house (5 kW is enough for 100 m 2);
• q - the minimum amount of specific heat, measured in kilowatts and depends on the brand of gas;
• B - boiler efficiency, percentages should be converted.

To determine the consumption, it is enough just to substitute the initial data into the formula. For a house with an area of ​​100 m2, 0.557 cubic meters per hour is enough. For 150 m2, 0.836 will be required, and for an area of ​​200 m2 - 1.114. To find out how much a gas unit consumes per day, it is enough to multiply the resulting number by 24. Multiplying the indicator by 30 will determine how many cubic meters are needed for heating per month.

As a rule, economical heating occurs up to a temperature of 55 ° C, and this must be substituted into the formula. The initial temperature is different and lies in the range of 4-10 °C. For a day, a family of 4 people needs approximately 80-100 liters for all needs, subject to economical use. It is not necessary to convert the volume into mass measures, since in the case of water they are almost the same (1 kg \u003d 1 l). It remains to substitute the obtained value of QDHW in the above formula and determine the additional gas consumption for DHW.

It is difficult to create comfort and coziness in a house without a traditional heating system. When choosing the appropriate equipment, it is important to know the approximate gas consumption for heating a house of a certain area. Based on these data, it is easy to calculate how much you have to pay for indoor heat per year.

Blue fuel is supplied centrally or stored in special tanks - cylinders or gas holders. The first option is the most rational and economical, since the operating costs for heating with main gas are several times lower. However, old pipes reduce efficiency, and natural fuel itself is not always of first-class quality, which increases costs. Autonomous heating systems operate on an expensive liquefied form. The cost of 1 liter will increase even more if transport costs for the delivery of cylinders are included in it.

The main consumption characteristics for heating with liquefied gas depend on the evaporation surface area (the larger it is, the higher the device's ability to convert liquid into a vapor phase). Horizontally located tanks are considered more advantageous. In general terms, known physical parameters are used for calculations.

The cost of heating with main gas is determined based on the power of the boiler.

Methodology for calculating gas for heating a house with examples

The financial costs of heating a building by the traditional method depend on many parameters: the type of windows, the quality of wall insulation, the height of ceilings, the ratio of floor areas and window openings, the required temperature, and other variable external factors. It is not possible to determine the exact value of costs, therefore, an average value is calculated.

With centralized gas supply, the maximum number of kWh per month is equal to the product of the area of ​​\u200b\u200bthe heated building, the boiler power and the number of hours in a month. However, homeowners are more interested in how to find out the gas consumption for space heating for the year. To do this, the duration of the heating season in monthly terms (for Russia on average - 7) is multiplied by the value obtained. The average annual costs are equal to half of the final value. Costs for autonomous gas supply (cylinders) are calculated based on the physical characteristics of liquefied gas: calorific value - 23,500 kJ / l; density - 0.52 kg/l; the amount of thermal energy released during the combustion of 1 liter of fuel - 6.53 kWh.

The average cost of filling a 50-liter cylinder is 680 rubles (the cylinder is filled by 80%, there are 42.5 liters in the container). So 1 liter of gas costs 16. With a boiler with an efficiency of 93%, 1 kWh is estimated at 2.63.

1. Calculation for a house of 100 m2

2. Calculation for a house of 200 m2

• In order to keep warm in such a building, a boiler with a capacity of 20 kWh is installed. Monthly maximum consumption: 20 x 30 x 24 = 14,400 kWh. Annual costs: 14,400 x 7 = 100,800 kWh. According to the methodology, the average calculation of natural gas for heating a house of 200 m2 is: 100,800 / 2 = 50,400 kWh. In monetary terms: 50,400 x 0.31 = 15,624 rubles.
• If we are talking about liquefied gas in cylinders, then 36,000 kWh per year is spent to heat the building. At a cost of 1 kWh equal to 2.63 rubles, the average annual costs are: 36,000 x 2.63 = 94,680.

Ways to reduce the cost of heating a house with gas

1. Maximum blocking of building heat losses. Even at the design stage, care should be taken about the compactness of the structure.

2. Installation of modern high-quality equipment.

3. Combining cylinders into a group reduces gas consumption in liters for heating a house, but for cottages with an area of ​​​​more than 200 m2, liquid fuel is expensive.

4. The use of automatic systems for adjusting the temperature of the air in the room (reducing heating at night, changing the heat supply, depending on external conditions, maintaining a fixed temperature).

When arranging the heating system and choosing an energy carrier, it is important to find out the future gas consumption for heating a house of 150 m2 or another area. Indeed, in recent years, a clear upward trend in natural gas prices has been established, the last rise in price by about 8.5% occurred recently, on July 1, 2016. This led to a direct increase in heating costs in apartments and cottages with individual heat sources using blue fuel. That is why developers and homeowners who are just choosing a gas boiler for themselves should calculate heating costs in advance.

Initial data for calculations

To perform a preliminary calculation, you need to find out the following parameters:

• the calorific value (calorific value) of natural gas supplied in your area;
• The efficiency of the boiler, which is planned to be installed in a house or apartment.

The calorific value of the fuel is taken according to the value of the lower calorific value of the main gas.

Theoretically, when burning 1 m³ of blue fuel, 9.2 kW of thermal energy is released. In practice, this value differs and, as a rule, to a smaller extent. Due to the same rise in price, some unscrupulous suppliers dilute the gas with air, which can reduce its calorific value to 7.5-8 kW / m³.

To determine the gas consumption for heating a house, it is better to find out the calorie value from the management company, and when this fails, take into account the figure with a margin: 8 kW / m³. If they share information with you about the specific heat of combustion and give a figure expressed in other units, kcal / h, then you can convert it to Watts by multiplying by a factor of 1.163.

Another important indicator that directly affects fuel consumption is the heat load on the heating system, which consists of heat losses through the building structures of the building and losses for heating the ventilation air. The best option is to perform or order an accurate calculation of all heat losses, but in the absence of another way out, you can determine the load in enlarged ways:

1. If the ceiling height does not exceed 3 m, then a heat consumption of 0.1 kW per 1 m² of the heated building area is assumed. Thus, for a house of 100 m2, about 10 kW of heat is needed, 150 m2 - 15 kW and 200 m2 - 20 kW of heat energy.
2. Put 40-45 W of heat per 1 m³ of heated space. The load is determined by multiplying this value by the volume of all heated rooms.

The efficiency of the heat generator, which affects the efficiency of fuel combustion, is indicated in its technical passport. If the unit has not yet been purchased, then you can take the efficiency of gas boilers of various types from the list:

• gas convectors - 86%;
• boilers with an open combustion chamber - 88%;
• heat generators with a closed chamber - 92%;
• condensing boilers - 96%.

Performing calculations

Preliminary calculation of gas consumption for heating is made according to the formula:

V \u003d Q / (q x efficiency / 100).

• q is the calorific value of the fuel, the default is 8 kW/m³;
• V is the desired flow rate of the main gas, m³ / h;
• Efficiency is the efficiency of fuel combustion by a heat source, expressed in %;
• Q is the heating load of a private house, kW.

As an example, it is proposed to calculate the gas consumption in a small cottage with an area of ​​150 m² with a heating load of 15 kW. It is planned that the task of heating will be performed by a heating unit with a closed combustion chamber (92% efficiency). The theoretical fuel consumption for 1 hour in the coldest period will be:

During the day, the heat generator will consume 2.04 x 24 = 48.96 m³ (rounded - 49 cubic meters) of natural gas - this is the maximum consumption on the coldest days. But during the heating season, the temperature can fluctuate between 30-40 ° C (depending on the region of residence), so the average daily gas consumption will be half as much, about 25 cubic meters.

Then, on average per month, a turbocharged boiler uses 25 x 30 = 750 m³ of fuel to heat a house with an area of ​​​​150 m², located in central Russia. Consumption is calculated in the same way for cottages of other sizes. Focusing on a preliminary calculation, it is possible to carry out measures aimed at reducing consumption even at the construction stage: insulation, selection of more efficient equipment and the use of automatic controls.

Autonomous heating of private houses with liquefied propane or its mixture with butane has not yet lost its relevance in the Russian Federation, although in recent years it has noticeably increased in price. It is all the more important to calculate the future consumption of this type of fuel for those homeowners who plan such heating. The same formula is used for the calculation, only instead of the net calorific value of natural gas, the value of the parameter for propane is set: 12.5 kW with 1 kg of fuel. The efficiency of heat generators when burning propane remains unchanged.

Below is an example calculation for the same building of 150 m², only heated with liquefied fuel. Its consumption will be:

• for 1 hour - 15 / (12.5 x 92 / 100) = 1.3 kg, per day - 31.2 kg;
• on average per day - 31.2 / 2 \u003d 15.6 kg;
• on average per month - 15.6 x 30 \u003d 468 kg.

When calculating the consumption of liquefied gas for heating a house, it must be taken into account that fuel is usually sold by volume measures: liters and cubic meters, and not by weight. This is how propane is measured when filling cylinders or a gas tank. This means that it is necessary to convert mass into volume, knowing that 1 liter of liquefied gas weighs about 0.53 kg. The result for this example will look like this:

468 / 0.53 \u003d 883 liters, or 0.88 m³, of propane will have to be burned on average per month for a building with an area of ​​​​150 m².

Given that the retail price of liquefied gas is an average of 16 rubles. for 1 liter, heating will result in a considerable amount, about 14 thousand rubles. per month for the same cottage for one and a half hundred squares. There is reason to think about how best to insulate the walls, and take other measures aimed at reducing gas consumption.

Many homeowners expect to use fuel not only for heating, but also for providing hot water. These are additional costs, they must be calculated, plus it is important to take into account the additional load on heating equipment.

The thermal power required for hot water supply is easy to calculate. It is necessary to determine the required amount of water per day and use the formula:

Q DHW \u003d cm (t 2 - t 1).

• c is the heat capacity of water, equal to 4.187 kJ/kg °C;
• t 1 - initial water temperature, ° С;
• t 2 - final temperature of heated water, ° С;
• m is the amount of water consumed, kg.

As a rule, economical heating occurs up to a temperature of 55 ° C, and this must be substituted into the formula. The initial temperature is different and lies in the range of 4-10 °C. For a day, a family of 4 people needs approximately 80-100 liters for all needs, subject to economical use. It is not necessary to convert the volume into mass measures, since in the case of water they are almost the same (1 kg \u003d 1 l). It remains to substitute the obtained value of Q DHW in the above formula and determine the additional gas consumption for DHW.