What is it - the specific consumption of thermal energy for heating a building? Is it possible to calculate the hourly heat consumption for heating in a cottage with your own hands? This article will be devoted to terminology and general principles calculation of the need for thermal energy.
The basis of new building projects is energy efficiency.
Terminology
What is specific heat consumption for heating?
We are talking about the amount of heat energy that must be brought inside the building in terms of each square or cubic meter to maintain normalized parameters in it, comfortable for work and living.
Usually, a preliminary calculation of heat losses is carried out according to enlarged meters, that is, based on the average thermal resistance of the walls, the approximate temperature in the building and its total volume.
Factors
What affects the annual heat consumption for heating?
- Duration of the heating season (). It, in turn, is determined by the dates when the average daily temperature in the street for the last five days falls below (and rises above) 8 degrees Celsius.
Useful: in practice, when planning the start and stop of heating, the weather forecast is taken into account. Long thaws occur in winter, and frosts can strike as early as September.
- Average temperatures of the winter months. Usually when designing heating system the average monthly temperature of the coldest month, January, is taken as a guideline. It is clear that the colder it is outside, the more heat the building loses through the building envelope.
- The degree of thermal insulation of the building greatly affects what will be the rate of thermal power for him. An insulated facade can reduce the need for heat by half relative to a wall made of concrete slabs or brick.
- building glazing factor. Even when using multi-chamber double-glazed windows and energy-saving spraying, noticeably more heat is lost through windows than through walls. How most of the facade is glazed - the greater the need for heat.
- The degree of illumination of the building. On a sunny day, a surface oriented perpendicular to the sun's rays can absorb up to a kilowatt of heat per square meter.
Clarification: in practice, the exact calculation of the amount of solar heat absorbed will be extremely difficult. Those same glass facades, which lose heat in cloudy weather, will serve as heating in sunny weather. The orientation of the building, the slope of the roof, and even the color of the walls will all affect the ability to absorb solar heat.
Calculations
Theory is theory, but how heating costs are calculated in practice country house? Is it possible to estimate the estimated costs without plunging into the abyss of complex heat engineering formulas?
Consumption of the required amount of thermal energy
Instructions for calculating the estimated amount required heat relatively simple. The key phrase is an approximate amount: for the sake of simplifying calculations, we sacrifice accuracy, ignoring a number of factors.
- The base value of the amount of thermal energy is 40 watts per cubic meter of cottage volume.
- To the base value is added 100 watts for each window and 200 watts for each door in the exterior walls.
- Further, the obtained value is multiplied by a coefficient, which is determined by the average amount of heat loss through the outer contour of the building. For apartments in the center apartment building a coefficient equal to one is taken: only losses through the facade are noticeable. Three of the four walls of the contour of the apartment border on warm rooms.
For corner and end apartments, a coefficient of 1.2 - 1.3 is taken, depending on the material of the walls. The reasons are obvious: two or even three walls become external.
Finally, in a private house, the street is not only around the perimeter, but also from below and above. In this case, a coefficient of 1.5 is applied.
Please note: for apartments on the extreme floors, if the basement and attic are not insulated, it is also quite logical to use a coefficient of 1.3 in the middle of the house and 1.4 at the end.
- Finally received thermal power multiplied by the regional coefficient: 0.7 for Anapa or Krasnodar, 1.3 for St. Petersburg, 1.5 for Khabarovsk and 2.0 for Yakutia.
In the cold climate zone — special requirements to heating.
Let's calculate how much heat is needed for a cottage measuring 10x10x3 meters in the city of Komsomolsk-on-Amur, Khabarovsk Territory.
The volume of the building is 10*10*3=300 m3.
Multiplying the volume by 40 watts/cube will give 300*40=12000 watts.
Six windows and one door is another 6*100+200=800 watts. 1200+800=12800.
A private house. Coefficient 1.5. 12800*1.5=19200.
Khabarovsk region. We multiply the need for heat by another one and a half times: 19200 * 1.5 = 28800. In total - at the peak of frost, we need about a 30-kilowatt boiler.
Calculation of heating costs
The easiest way to calculate the consumption of electricity for heating: when using an electric boiler, it is exactly equal to the cost of thermal power. With continuous consumption of 30 kilowatts per hour, we will spend 30 * 4 rubles (approximate current price of a kilowatt-hour of electricity) = 120 rubles.
Fortunately, the reality is not so nightmarish: as practice shows, the average heat demand is about half the calculated one.
- Firewood - 0.4 kg / kW / h. Thus, the approximate norms for the consumption of firewood for heating in our case will be equal to 30/2 (the rated power, as we remember, can be divided in half) * 0.4 \u003d 6 kilograms per hour.
- The consumption of brown coal in terms of a kilowatt of heat is 0.2 kg. The consumption rates of coal for heating are calculated in our case as 30/2*0.2=3 kg/h.
Brown coal is a relatively inexpensive heat source.
- For firewood - 3 rubles (the cost of a kilogram) * 720 (hours in a month) * 6 (hourly consumption) \u003d 12960 rubles.
- For coal - 2 rubles * 720 * 3 = 4320 rubles (read others).
Conclusion
You can, as usual, find additional information on cost calculation methods in the video attached to the article. Warm winters!
The procedure for calculating heating in housing stock depends on the availability of metering devices and on how the house is equipped with them. There are several options for completing multi-apartment residential buildings with meters, and according to which, heat energy is calculated:
- the presence of a common house meter, while apartments and non-residential premises are not equipped with metering devices.
- heating costs are controlled by a common house device, and all or some rooms are equipped with metering devices.
- there is no general house device for fixing the consumption and consumption of thermal energy.
Before calculating the number of gigacalories spent, it is necessary to find out the presence or absence of controllers in the house and in each individual room, including non-residential ones. Let's consider all three options for calculating thermal energy, for each of which a specific formula has been developed (posted on the website of state authorized bodies).
Option 1
So the house is equipped control device, and some rooms were left without it. Here it is necessary to take into account two positions: the calculation of Gcal for heating an apartment, the cost of thermal energy for general house needs (ODN).
AT this case formula No. 3 is used, which is based on the readings of the general meter, the area of \u200b\u200bthe house and the footage of the apartment.
Calculation example
We will assume that the controller recorded the heating costs of the house at 300 Gcal / month (this information can be obtained from the receipt or by contacting management company). For example, the total area of the house, which consists of the sum of the areas of all premises (residential and non-residential), is 8000 m² (you can also find this figure from the receipt or from the management company).
Let's take the area of an apartment of 70 m² (indicated in the data sheet, rental agreement or registration certificate). The last figure, on which the calculation of payment for consumed heat energy depends, is the tariff set by authorized bodies RF (indicated in the receipt or find out in the house management company). Today, the heating tariff is 1,400 rubles/gcal.
Substituting the data in formula No. 3, we get the following result: 300 x 70 / 8,000 x 1,400 \u003d 1875 rubles.
Now you can proceed to the second stage of accounting for heating costs spent on the general needs of the house. Two formulas are required here: the search for the volume of services (No. 14) and the payment for the consumption of gigacalories in rubles (No. 10).
In order to correctly determine the volume of heating in this case, it will be necessary to sum up the area of \u200b\u200ball apartments and premises provided for common use(information provided by the management company).
For example, we have a total footage of 7000 m² (including apartments, offices, retail premises.).
Let's start calculating the payment for the consumption of thermal energy according to formula No. 14: 300 x (1 - 7,000 / 8,000) x 70 / 7,000 \u003d 0.375 Gcal.
Using formula No. 10, we get: 0.375 x 1,400 = 525, where:
- 0.375 - volume of service for heat supply;
- 1400 r. – tariff;
- 525 rubles - amount of payment.
We summarize the results (1875 + 525) and find out that the payment for heat consumption will be 2350 rubles.
Option 2
Now we will calculate payments in those conditions when the house is equipped with a common meter for heating, as well as some apartments are equipped with individual meters. As in the previous case, the calculation will be carried out in two positions (thermal energy consumption for housing and ONE).
We will need formulas No. 1 and No. 2 (accrual rules according to the testimony of the controller or taking into account the norms for heat consumption for residential premises in gcal). Calculations will be carried out in relation to the area of a residential building and an apartment from the previous version.
- 1.3 gigacalories - readings of an individual counter;
- 1 1820 r. - approved rate.
- 0.025 gcal - standard indicator of heat consumption per 1 m² of area in an apartment;
- 70 m² - area of the apartment;
- 1 400 rubles - tariff for thermal energy.
As it becomes clear, with this option, the payment amount will depend on the availability of a metering device in your apartment.
Formula No. 13: (300 - 12 - 7,000 x 0.025 - 9 - 30) x 75 / 8,000 \u003d 1.425 gcal, where:
- 300 gcal - indications of a common house meter;
- 12 gcal - the amount of thermal energy used for heating non-residential premises;
- 6,000 m² - the sum of the area of all residential premises;
- 0.025 - standard (thermal energy consumption for apartments);
- 9 gcal - the sum of indicators from the meters of all apartments that are equipped with metering devices;
- 35 gcal - the amount of heat spent on supply hot water in the absence of its centralized supply;
- 70 m² - area of the apartment;
- 8,000 m² - total area (all residential and non-residential premises in the house).
note that this option includes only real amounts of energy consumed and if your house is equipped with a centralized hot water supply, then the amount of heat spent on hot water needs is not taken into account. The same applies to non-residential premises: if they are not in the house, then they will not be included in the calculation.
- 1.425 gcal - the amount of heat (ONE);
- 1820 + 1995 = 3,815 rubles - With individual counter.
- 2 450 + 1995 = 4445 rubles. - without individual device.
Option 3
We are left with the last option, during which we will consider the situation when there is no heat meter on the house. The calculation, as in previous cases, will be carried out in two categories (thermal energy consumption for an apartment and ONE).
We will deduce the amount for heating using formulas No. 1 and No. 2 (rules on the procedure for calculating thermal energy, taking into account the readings of individual metering devices or according to established standards for residential premises in Gcal).
Formula No. 1: 1.3 x 1,400 \u003d 1820 rubles, where:
- 1.3 gcal - readings of an individual meter;
- 1 400 rubles - approved rate.
Formula No. 2: 0.025 x 70 x 1,400 = 2,450 rubles, where:
- 1 400 rubles - approved rate.
As in the second option, the payment will depend on whether your housing is equipped with an individual heat meter. Now it is necessary to find out the amount of heat energy that was spent on general house needs, and this must be done according to formula No. 15 (volume of service for one unit) and No. 10 (amount for heating).
Formula No. 15: 0.025 x 150 x 70 / 7000 \u003d 0.0375 gcal, where:
- 0.025 gcal - standard indicator of heat consumption per 1 m² of living space;
- 100 m² - the sum of the area of \u200b\u200bthe premises intended for general house needs;
- 70 m² - the total area of the apartment;
- 7,000 m² - total area (all residential and non-residential premises).
Formula No. 10: 0.0375 x 1,400 = 52.5 rubles, where:
- 0.0375 - volume of heat (ONE);
- 1400 r. - approved rate.
As a result of the calculations, we found out that the full payment for heating will be:
- 1820 + 52.5 \u003d 1872.5 rubles. - with individual counter.
- 2450 + 52.5 \u003d 2,502.5 rubles. – without individual counter.
In the above calculations of payments for heating, data on the footage of the apartment, house, as well as on the meter indicators, which may differ significantly from those that you have, were used. All you need to do is plug your values into the formula and make the final calculation.
The issue of calculating the amount of payment for heating is very important, since consumers often receive quite impressive amounts for this utility service, at the same time having no idea how the calculation was made.
Since 2012, when Decree of the Government of the Russian Federation dated May 06, 2011 No. 354 “On the provision of utility services to owners and users of premises in apartment buildings and residential buildings” came into force, the procedure for calculating the amount of payment for heating has undergone a number of changes.
The calculation methods changed several times, heating provided for general house needs appeared, which was calculated separately from the heating provided in residential premises (apartments) and non-residential premises, but then, in 2013, heating was again calculated as a single public service without fee sharing.
The calculation of the amount of the heating fee has changed since 2017, and in 2019 the calculation procedure has changed again, new formulas for calculating the amount of the heating fee have appeared, which are not so easy for the average consumer to understand.
So, let's sort it out in order.
In order to calculate the amount of payment for heating in your apartment and choose the desired calculation formula, you must first know:
1. Does your house have a centralized heating system?
This means whether thermal energy for heating needs in your apartment building already in ready-made using centralized systems or heat energy for your home is produced independently using equipment that is part of the common property of the owners of the premises in apartment building.
2. Is your apartment building equipped with a common house (collective) metering device and are there individual heat energy metering devices in residential and non-residential premises of your house?
The presence or absence of a common house (collective) meter at the house and individual meters in the premises of your house significantly affects the method of calculating the amount of payment for heating.
3. How are you charged for heating - during the heating season or evenly throughout the calendar year?
The method of payment for the heating utility service is accepted by the authorities state power subjects Russian Federation. That is, in different regions of our country, payment for heating can be charged differently - throughout the year or only during the heating season, when the service is actually provided.
4. Are there rooms in your house that do not have heating devices (radiators, batteries), or that have their own sources of heat energy?
It was from 2019, in connection with the court decisions, the proceedings on which took place in 2018, that the calculation began to include premises in which there are no heating devices (radiators, batteries), which is provided technical documentation for a house, or residential and non-residential premises, the reconstruction of which, providing for the installation of individual sources of heat energy, was carried out in accordance with the requirements for the reconstruction established by the legislation of the Russian Federation in force at the time of such reconstruction. It should be reminded that earlier the methodology for calculating the size of the payment for heating did not provide for a separate calculation for such premises, therefore, the calculation of the payment was carried out on a general basis.
In order to make the information on calculating the amount of the heating fee more understandable, we will consider each method of charging the fee separately, using one or another calculation formula in a specific example.
When choosing a calculation option, it is necessary pay attention to all the components that determine the calculation method.
Below are various calculation options, taking into account individual factors that determine the choice of calculating the amount of heating payment:
Calculation No. 1: The amount of payment for heating in residential / non-residential premises during the heating period.
Calculation No. 2: Amount of payment for heating in residential / non-residential premises, there is no ODPU on an apartment building, the calculation of the amount of the fee is carried out during the calendar year(12 months).
To get acquainted with the order and example of calculation →
Calculation No. 3: The amount of payment for heating in residential / non-residential premises, ODPU is installed on an apartment building, there are no individual metering devices in all residential / non-residential premises.
Heating systems and supply ventilation must work in buildings at average daily outdoor temperatures tn.day from +8С and below in areas with design outdoor air temperature for heating design up to -30С and at tn.day from +10С and lower in areas with design outdoor air temperature for heating design below - 30C. The values of the duration of the heating period No and the average outdoor temperature tn.av are given in and for some cities of Russia in Appendix A. For example, for Vologda and adjacent areas No = 250 days / year, and tn.av = - 3.1С at tn.day=+10С.
Thermal energy consumption in GJ or Gcal for heating and ventilation of buildings for a certain period (month or heating season) is determined by the following formulas
Qo.= 0.00124NQo.r(tin - tn.av)/(tin - tn.r),
Qin. \u003d 0.001ZinNQin.r (tin - tn.av) / (tin - tn.r),
where N is the number of days in the billing period; for heating systems, N is the duration of the heating season No from Appendix A or the number of days in a particular month Nmonth; for supply systems ventilation N is the number of working days of an enterprise or institution during the month Nm.v or the heating season Nv, for example, with a five-day working week Nm.v = Nmonth5/7, and Nv = No5/7;
Qо.р, Qв.р - calculated thermal load(maximum hourly consumption) in MJ / h or Mcal / h for heating or ventilation of the building, calculated by formulas.
tvn - the average air temperature in the building, given in Appendix B;
tn.av - the average outdoor temperature for the period under consideration (heating season or month), taken according to or according to Appendix B;
tn.r - design outdoor air temperature for heating design (the temperature of the coldest five-day period with a security of 0.92);
Zв - the number of hours of operation of supply ventilation systems and air curtains during the day; for one-shift work of a workshop or institution, Zv = 8 hours/day, for two-shift operation - Zv = 16 hours/day, in the absence of data for the microdistrict as a whole Zv = 16 hours/day.
The annual heat consumption for hot water supply Qgw.year in GJ/year or Gcal/year is determined by the formula
Qgw.year = 0.001Qday (Nz + Nl Kl),
where Qday - daily heat consumption for hot water supply of the building in MJ / day or Mcal / day, calculated by the formula;
Nz - the number of days of hot water consumption in the building for the heating (winter) period; for residential buildings, hospitals, grocery stores and other buildings with daily operation of hot water supply systems, Nz is taken equal to the duration of the heating season No; for enterprises and institutions, Nz is the number of working days during the heating season, for example, with a five-day working week, Nz = No5/7;
Nl - the number of days of hot water consumption in the building during the summer period; for residential buildings, hospitals, grocery stores and other buildings with daily operation of hot water supply systems Nl \u003d 350 - No, where 350 is the estimated number of days in a year of operation of HW systems; for enterprises and institutions Nl is the number of working days during summer period, for example, with a five-day working week Nl \u003d (350 - No) 5/7;
Kl - coefficient taking into account the reduction in heat consumption for HW due to the higher initial temperature of the heated water, which is equal to tx.z = 5 degrees in winter, and on average tx.l = 15 degrees in summer; in this case, the coefficient Kl will be equal to Kl \u003d (tg - tx.l) / (tg - tx.z) \u003d (55 - 15) / (55 - 5) \u003d 0.8; when water is taken from wells, it may turn out to be tx.l = tx.s and then Kl = 1.0;
The coefficient that takes into account the possible decrease in the number of hot water consumers in the summer due to the departure of part of the residents from the city on vacation and is assumed to be = 0.8 for the housing and communal sector (for resort and southern cities = 1.5), and for enterprises = 1.0.
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