WO2021139844A1

WO2021139844A1 - Method for determining an energy consumption for heating or cooling of apartments

Info

Publication number: WO2021139844A1
Application number: PCT/CZ2021/050001
Authority: WO
Inventors: Otakar Černý; Stanislav Honus
Original assignee: Vysoká Škola Báňská - Technická Univerzita Ostrava
Priority date: 2020-01-06
Filing date: 2021-01-05
Publication date: 2021-07-15
Also published as: CZ308726B6; CZ20207A3

Abstract

Method for determining an energy consumption for heating or cooling of apartments in an apartment building especially by heating based of energetic processing of biomass, natural gas and other conventional fuels. In a period, an energy consumption in radiators (3), a temperature of the heating and cooling distribution system (2) temperatures of the supply and return pipes (1) of the heating and cooling distribution system (2), and outdoor temperatures are measured. The measured data are used for determination of energy or heat consumption. The heat consumption transferred through walls and ventilation is deducted from the sum of energy consumption in the radiators (3) and in the heating and cooling distribution system (2). This difference is added to the average energy consumption of each apartment. The compensated energy consumption is determined as the average value of total energy consumption of each apartment and adjacent apartments.

Description

Method for determining an energy consumption for heating or cooling of apartments

Field of the Invention

The invention relates to a method for determining the energy consumption for heating or cooling of apartments in an apartment building.

Background of the Invention

The energy consumption for heating or cooling depends on constantly increasing heat prices, with no difference whether the heat is gained from natural gas and other conventional fuels or from new sources of energy, from biomass for example.

Therefore there is tendency not only to improve the methods of heat recovery but also to increase the efficiency of heating or cooling. The costs of these processes are substantially connected with motivation of users, i.e. with the method of dividing these costs among individual users.

In buildings, such as apartment buildings or non-residential buildings, which are arranged and used in accordance with the character of apartment buildings, hereinafter referred to as “buildings”, various systems of central or floor heating or cooling (air conditioning) are operated and the costs of their operation for individual apartments are determined at least once a year. The costs of heating or cooling in apartments are defined as the sum of the basic cost component, which cannot be measured, and the consumption cost component, which is measured.

During heating, heat is supplied to the apartments through the heating system and removed through exterior walls and ventilation; during cooling, heat is supplied to the apartments through exterior walls and ventilation and removed through the cooling system. In general, energy for heating or cooling is supplied to the building and subsequently to the individual apartments by a central or floor system, and this energy is then transferred in the form of heat through the exterior walls of the apartments and ventilation. In addition, both systems have two-way heat transfers inside the building through the walls of the apartments adjacent to other apartments or common areas.

For example, heat from electrical and gas appliances, heat supplied by solar radiation and heat emitted by people need to be removed through apartment walls and ventilation, and therefore the heat transferred will always be greater than the energy consumed by heating equipment.

On the contrary, for the same reason, the cooling system needs more energy than the heat supplied through walls and ventilation.

If the costs of heating or cooling are not determined in a sufficiently objective manner, such experience is reflected in the market price of the apartments in question and in the worsened relations of the residents of the building, or even in legal disputes.

In order to correctly determine the costs of heating or cooling in individual apartments, it is necessary to know, in addition to the total costs of energy supplied by heating or cooling equipment to the building, primarily the temperature conditions of the building and apartments, in particular:

- outdoor temperature,

- room or apartment temperature,

- temperature in common areas (basements, corridors), hereinafter also referred to as “basements”,

- temperature or consumption of radiators (adjustable heating or cooling elements) or quantity proportional to these quantities,

- temperature of heating water at the inlet and outlet in the domestic distribution station in the case of central hot water heating.

Heat consumption also depends on the dimensions and physical properties of materials of the heat exchange surface areas of apartments, heating water distribution system and heating elements. The heat transfer through exterior walls and the ventilation of apartments are also affected by wind speed, which increases parabolically with height above ground level. Ventilation of apartments takes place mainly spontaneously, objectively due to leaks in windows and doors and also by central ventilation system, in particular if it is powered by an uncontrolled wind drive on the roof of the building. This is approached by the subjective component of ventilation according to the needs of users.

The realistic determination of the costs of heating or cooling from the above data is therefore quite complicated.

Using the calculation procedures used so far, allocators try to simplify the determination of the costs of heating or cooling as much as possible. However, this is at the expense of apartment users in violation of the laws of physics, so the results are often very far from objective reality and are therefore unfair.

These procedures are not prohibited only in order to avoid the greatest unfairness due to the non-objectivity of calculation methods, apartment-rate restrictions are usually set by law for the basic cost component and for possible deviations of total costs from the average.

The Decree in the Czech Republic, for example, stipulates the share of basic cost component of heating in the amount of 30 to 50% and the rest of the costs is the consumption component. It also sets limits of -20% to +100% for the range of permissible values for the costs of heating from the average.

Heating and cooling are governed by the same laws of physics and, therefore, only the term “heating” is used in the following text. a) Most often, the consumption cost component of heating in apartments is divided by the division method according to the heat consumption in radiators, while the basic cost component is divided according to the floor area of apartments. For floor systems, consumption is determined by absolute, billing meters available in each apartment. In central systems, the total consumption determined by billing meter in the basement is usually distributed among the apartments in a proportional manner by means of indicators, generally meters, of consumption on the radiators. Consumption indicators cumulatively register the temperature or its equivalent, i.e. divisions, for individual radiators. In the case of central hot water heating, the distribution of costs is determined by this method according to the formula

N_i= N_z,i + N_sp,i where

Ni - costs of heating of the apartment, N_z,i = N.Z.S_b,i/∑S_b,i - basic cost component

N_sp,i = N.(l-Z).k_p.P_i.di/∑k_p.P_i.d_i - consumption cost component

N - costs of heating of the building,

Z = e.g. 0.3 to 0.5 - share of the basic cost component of the total costs in the building,

S_b,i - floor area of the apartment, k_p - coefficient of position of the apartment,

P_i - nominal heating power of the radiator, d_i - number of measured divisions on the radiator temperature (consumption) indicator.

The nominal heating power of the radiator is proportional to the heat transfer surface area of the radiator.

The consumption cost component is sometimes distributed for whole groups of apartments, i.e. groups of apartments above each other, according to the floor area of apartments and only within the given group the consumption cost component in apartments is distributed according to measured divisions.

The number of measured divisions on the indicator is proportional to the difference between the average temperature of the radiator and the activation temperature of the indicator, i.e. the temperature at which the indicator begins to register the temperature.

The general problem of these indicators is the setting of the activation temperature of the indicator - if it is set low, e.g. for evaporating indicators, it also registers high room temperature in summer, differently according to the floor and orientation, as a result of which it can show up to 30% higher heat consumption in the radiator, and if it set high, e.g. for electronic indicators, it does not register lower radiator temperatures at the beginning and end of the heating period. The summer evaporation of evaporating indicators can be eliminated, for example, by reading the measured data after the end of the heating period and at the beginning of the next heating period, which, however, slightly increases the billing costs.

In the above calculation formula, the data on heat consumption in each apartment is multiplied by the coefficient of position, which should objectively correct unequal heat losses through exterior walls of the apartment according to its location in the building, but is usually determined by more or less inaccurate calculation or even estimate.

With this method, allocators, on the one hand, offer apartment users the opportunity to easily achieve cost savings by limiting or even completely stopping the radiators during a period of their absence and, on the other hand, they try to put the responsibility for the consequences on their part.

The fact is that as soon as the temperature in the apartment starts to decrease by stopping the radiators, virtually all the missing heat is immediately replenished through the walls from the adjacent heated apartments, which then need to be heated significantly more than would otherwise be necessary. In the case of short-term changes, the monitoring of this process is somewhat distorted by the accumulation of heat, in particular in building structures.

For example, in an apartment surrounded by unheated apartments, heating costs according to this method, to maintain normal temperature, will increase at least twice that of unheated apartments without adequate compensation, while cost savings below the lower cost limit that were unfairly calculated in unheated apartments are usually distributed on an apartment rate among all other apartments in the building according to the size of the floor area.

The share of the basic cost component in buildings is also usually determined by estimate, although in reality it depends on a number of technical quantities, in particular on the thermal insulation condition of the building, parameters of heating distribution system, temperature conditions and total heat consumption in the building in the given year.

The heat source in the basic cost component is insulated horizontal heating pipes and radiators in common areas, mainly in the basement or corridors, and non-insulated, usually vertical, heating pipes (risers) in apartments.

These heating pipes are very unevenly distributed in the building, are operated continuously and are not controllable by apartment users.

The heating power of risers depends mainly on the temperature of the supply and return branches of the piping.

In addition, the diameter of risers, the flow of heating water and its temperature gradually decrease with the height above ground level, which also gradually and quite non-linearly reduces the heating power of risers, depending on the consumption of radiators. On the lower floor levels, the heating power of risers can be relatively high, often so much that the apartment user does not have to open the radiator valves for almost the whole winter; on the top floor level, on the other hand, there are no risers, so all the heat must be supplied to the apartment by radiators. The heating distribution system can supply up to 90% or more of heat in the lower apartments and 0 in the upper apartments.

In taller buildings, there may be expansion loops on the risers, which also increase the heat supply in the apartments in question.

Designers dimension the heating power of risers in relation to the floor area of the apartment unevenly not only in the vertical direction, i.e. along the height of the building, but also in the horizontal direction, in apartments on the same floor this ratio can vary by tens of percent.

Reducing the heating water temperature, reducing differences in diameter of risers and reducing the share of heat transferred by risers are the goals of companies that specialize in technically and financially very demanding reconstruction of heating distribution systems together with electronic control of heating water temperature and flow using complex electro- hydraulic systems.

The mentioned calculation method completely omits the heat flows between apartments, the dimensioning of risers or the different level of ventilation of apartments by their users; there are extremely large differences even between neighbouring apartments in the resulting costs of heating.

This method is a problem in buildings with central and floor heating in winter, as well as cooling in summer. b) The less used direct degree-day, graded method determines the costs of heating according to the difference between the measured air temperature in apartments and the outdoor temperature:

N_i=N.(Z.S_b,i/∑Sb_b,i + (l-Z).S_b,i.(t_m,i-t_e)/∑(S_b,i.(t_m,i-t_e)))

Compared to the previous method, this method faces the opposite, but also unpleasant extreme - it is too egalitarian, the resulting costs are almost identical to the average costs.

This levelling partially covers the characteristic shortcomings of the method - when the air temperature in the apartment increases, the resulting costs of heating of the apartment increase even if the temperature is increased by simultaneous heating from other than the central source, and conversely, in direct proportion, a reduction in the air temperature, for example by ventilation, the resulting costs of the apartment are reduced according to this method, even with the same heat consumption in radiators. Even with high heat consumption in radiators, the resulting costs of a given apartment will increase only minimally if the user maintains the original temperature in the room by removing excess heat, because increased consumption is calculated for all apartments in the building by floor area.

This method also considers radiators as the only source of heat in the apartment, it neglects the fundamental influence of risers, ventilation and heat transfer on the energy balance.

However, allocators using the degree-day method make a virtue out of a necessity by considering thermal comfort as the main and sufficient criterion for the costs of heating and use room temperature as an indicator, although it is known that the price of better thermal comfort is often significantly higher than would correspond to the temperature conditions in apartments according to the given formula. c) The same formula and arguments in defence are used by the so-called modified degree-day method, in which the costs of heating for each heated room are determined using data from a combined indicator mounted on the radiator surface and indicating the temperature at two or three points of the radiator, while calculating the room air temperature from these data.

This method creates the impression of perfection, as it requires much more complex equipment (patented sensor) than the direct degree-day method, and the formula for calculating the room temperature contains a number of empirical coefficients.

However, the name “degree-day”, although indirect, is misleading for this method, as the calculation of costs here is not derived from the actual room temperature, but from the temperature of radiators.

However, the principle of the method for calculating the costs is completely misleading, as it is based on incorrect thermodynamic interpretation of the measured data.

The difference of temperatures measured at two points of the radiator is calculated here, while the inlet (upper) temperature of all radiators in the apartment is almost the same and the final (lower) temperature fluctuates, and this difference is supposedly proportional to radiator power, i.e. heat consumption; higher room temperature is also derived from higher difference.

However, the exact opposite is physically true - the lower the lower temperature of the radiator, the larger the temperature difference between the sensors on the radiator, but also the lower the average temperature of the radiator, therefore the lower radiator power and heat consumption must be and the lower room temperature must be.

The temperature difference of heating surface can be applied when calculating the heating power of the radiator, but then it is necessary to simultaneously measure the flow of heating water in the radiator. If the water flow is not measured, then the difference between the mean temperature of the radiator and the room temperature must be applied, as well as the size of the heat transfer surface area of the radiator:

Pr— C_v.n _v.(t_p-t_k)— k_r.S_r.(t_s-t_m)— k_r.S_r.((t_p+t_k)/2-t_m), where

P_r - heating power of the radiator,

C_v - specific heat of water m_v - flow rate of heating water k_r - coefficient of heat transfer of the radiator

S_r - heat transfer surface area of the radiator t_p - initial surface temperature t_k - final surface temperature t_s - mean temperature of the radiator t_m - room temperature

This method also does not take into account the different heating powers of risers in the apartments, the heat transfer between the apartments and to the common residential areas, as well as different levels of ventilation, which have a significant effect on room temperature and heating costs.

The purpose of the invention is to provide a method for determining the costs of heating or cooling which best overcomes the drawbacks of the methods mentioned.

Summary of the Invention

The invention solves this problem by a method for determining the energy consumption for heating or cooling of apartments in an apartment building especially by means of heat recovered by energetic processing of biomass, natural gas and other conventional fuels. The heating or cooling system of the apartment building comprises meters of energy consumption in radiators, temperature meters of heating or cooling distribution system and an outdoor temperature meter. The substance of this method consists in that in the evaluated period continously or periodically

- the energy consumption in radiators is measured by meters of energy consumption in radiators and the measured data are used for calculation of energy consumption for each apartment,

- the temperatures of the heating and cooling distribution system are measured by means of the temperature meters of heating or cooling distribution system and the measured data are used for calculation of energy consumption in the heating or cooling distribution system for each apartment,

- the outdoor temperatures are measured by means of the outdoor temperature meter and the measured data are used for calculation of the heat consumption transferred through walls and ventilation for each apartment,

- first the total energy consumption for heating and cooling for each apartment is determined by deducting the apartment’s costs of heat necessarily transferred through walls and ventilation from the sum of the apartment’s costs of energy consumed in radiators and heating or cooling distribution system and this difference is added to the average costs of the apartment of heating or cooling, whereupon the compensated costs of the apartment of heating or cooling shall be determined as the average of the total costs of heating or cooling of the given apartment and adjacent apartments, taking into account the size of apartments

The invention is explained in more detail in the following procedure:

The term “apartment building” also means a non-residential building, whose layout and use correspond to the character of an apartment building, hereinafter also referred to as “building”. a) The following quantities are measured continuously or periodically in the evaluated period:

- outdoor temperature, preferably for a building or group of buildings,

- energy consumption or temperature of heating or cooling equipment in apartments or even in a building, where:

- in the case of central arrangement of heating equipment, the energy consumption and the temperature of heating fluid in the supply and return pipes in the building or in the nearest distribution station and the temperature or temperature equivalent of heat transfer surface areas of heating or cooling elements, generally also radiators, in apartments are measured using ratio meters and possibly consumption of heating or cooling elements using absolute meters,

- in the case of floor arrangement of heating or cooling equipment, only its total energy consumption is preferably measured directly in the individual apartments,

- preferably, air temperature in apartments or even in individual rooms.

The heating or cooling fluid is most often water in hot water systems or air in hot air systems. The above data can be preferably obtained from the following meters:

- absolute energy consumption meter for heating or cooling for a building or group of buildings,

- outdoor temperature registration meter for a building or group of buildings,

- temperature registration meter at the inlet of heating or cooling fluid for a building or group of buildings,

- temperature registration meter at the outlet of heating or cooling fluid for a building or group of buildings,

- ratio or absolute temperature or energy consumption registration meters for heating or cooling elements in apartments, in general also energy consumption meters in radiators,

- air temperature registration meters in residential rooms or at the reference point of apartments.

For all measured temperatures, the average of measured values for the evaluated period is calculated.

The evaluated period of operation of the heating or cooling device is the winter/summer, heating or cooling period.

If the air temperature is measured only in some, e.g. heated or cooled rooms, their average temperature can be calculated taking into account the size, preferably the volume of the rooms where the measurement is performed. The resulting average air temperature in the apartment can then be preferably determined according to the formula t_b,i — ∑t_m,i· V _m,i/∑V _m,i , with the same construction height of all rooms, their floor area can be preferably used according to the formula t_b,i — ∑t_m,i· S _m,i/∑S _m,i , where t_m,i - air temperature in the measured room V_m,i - volume of the measured rooms S_m,i - floor area of the measured room

The air temperature in other rooms can be preferably derived from the average air temperature in the measured rooms, preferably by means of a uniform constant, e.g. -0.5°C.

In order to be able to evaluate the measured temperatures only for the monitored heating period, the values measured in the other period of the year are preferably excluded from the year-round set of measurements, e.g. to ensure relevant temperature equivalent values of radiators using evaporating indicators the summer evaporation values are preferably subtracted.

The procedure for central hot water heating or cooling, which is the most complex system, will be given in the following description. b) The total costs of the apartment of heating or cooling are calculated according to the formula

N_i = N_p,i - N_o,i + N_stř.i , provided that the costs of the building of the energy consumed by heating or cooling equipment are equal to the costs of the building of the heat necessarily transferred through apartment walls and ventilation, preferably according to the formula

∑N_p,i = ∑N_0,i = ∑N_stř.i = ∑N_i , where N_i - total costs of the apartment of heating or cooling,

N_p,i = N_ski,i + N_st,i + N_r,i - costs of the apartment of the energy consumed by heating or cooling equipment,

N_o,i = N_skl,i + N_b,i - costs of the apartment of the heat necessarily transferred through apartment walls and ventilation,

N_stř.i = N_sk,n.S_i/∑S_i - average share of the apartment from the group’s costs related to the floor area of the apartment. c) The heating or cooling capacity of the building is calculated:

N - costs of heating or cooling of the building q - specific price of heat

Q = N/q - energy consumption for heating or cooling of the building T - duration of heating or cooling period P = Q/T - heating or cooling capacity of the building, the heating or cooling power of the heating or cooling distribution system in the basement is calculated

P_skl — ∑k_skl,i · L_skl,i · ( t_tr- t_m,i) , where k_Skl,i - coefficient of heat transfer of a given section of heating or cooling distribution system in the basement

L_Skl,i - length of the section of heating or cooling distribution system in the basement, the heating or cooling power of the risers is calculated for each apartment:

P_st = ∑P_st,b,i - heating or cooling power of risers in the building P_st,b,i = ∑P_st,i - heating or cooling power of risers in the apartment P_st,i = ∑k_st,i.k_lo,i.k_k,i.L_i.(t_st,i-t_m,i) - heating or cooling power of the riser in the apartment where k_st,i = f(∑D_i, t_st,i, Δt_st,i) - coefficient of heat transfer of risers k_lo,i - coefficient of summer evaporation k_k,i = f(∑R_r,b,i/R_r,sk,n) - coefficient of flow accumulation in risers L_i - length of the riser in the apartment Di - diameter of the riser in the apartment and the balance consists of the heating or cooling power of radiators:

P_r = P - P_skl - P_st - heating or cooling power of radiators in the building, which is divided into groups by the size of apartments:

P_r,_sk,n = P_r.S_sk,n/S - heating or cooling power of radiators in the group where

S_sk,n = ∑S_b,i - floor area of the group S_b,i = ∑S_i - floor area of the apartment

S = ∑S_sk,n - floor area of all groups in the building, apartment floor area of the building n - group index and within the group, it is divided into individual apartments by the heating or cooling power of radiators:

R_r,sk,n = ∑R_r,_b,i - converted consumption of radiators in the group R_r,_b,i = ∑R_r,i - converted consumption of radiators in the apartment R_r,i = di.P_r,j,i - converted consumption of the radiator

P_r,_b,i = P _{str sk}.R_r,b,i/R, _r,sk,n - heating or cooling power of radiators in the apartment, where d_i - average temperature of the radiator or its equivalent according to the data of heat consumption indicator

P_r,j,i - nominal heating or cooling power of the radiator

The temperatures of heating or cooling water in pipes in the basement and in risers are preferably taken or derived from the temperatures of supply and return pipes: t_tr = (t_p + t_z )/2 - mean water temperature in pipes in the basement t_p - water temperature in the supply pipe t_z - water temperature in the return pipe

Unlike pipes in the basement, risers are not insulated, therefore the heating or cooling power of these risers is preferably calculated taking into account, in addition to pipe dimensions, coefficient of heat transfer and temperature difference between risers and room air, the temperature drop of risers as a result of heat removal through walls of risers: t_st,i = t_tr - At_st,i - water temperature in risers in the apartment At_st,i - temperature drop of risers in the apartment

Since only the amount of heating or cooling water consumed in radiators flows through risers, the effect of flow, proportional to the consumption in radiators and continuously accumulated in risers can be preferably taken into account in the calculation of the heating or cooling power of risers in each apartment: k_k,i = f(∑R_r,b,i/Rr_,sk,n) - coefficient of flow accumulation in risers

The share of the basic cost component is calculated as the share of the heating or cooling power of heating or cooling distribution system in the basement and the heating or cooling power of risers from the total heating or cooling power:

Z = (P_skl + P_st )/P If the calculated share of the basic cost component exceeds the limits set by law, it is necessary to correct the costs of heating or cooling of the basement and risers accordingly. d) The costs of energy for heating or cooling supplied to the building shall be distributed among the apartment groups according to the size of apartments in these groups. If the height of all apartments is the same, it is sufficient to use only the floor area as a criterion for the size of the apartment. This eliminates the influence of cardinal points and unbalanced dimensioning of risers on costs in groups:

N_sk,n = N.S_sk,n/∑S_sk,n - group costs of energy for heating or cooling

In each group, the costs of energy for heating or cooling of the basement, i.e. common areas, by heating or cooling distribution system, and the costs of energy for heating or cooling of apartments by risers are distributed according to their heating or cooling power:

N _skl.n = N_sk,n.P_skl/P - group costs of energy for heating or cooling of the basement N_st,n = N_sk,n.P_st/P - group costs of energy for heating or cooling of apartments by risers

The costs of energy for heating or cooling of the basement are preferably distributed among apartments according to their floor areas:

N_skl,i = N_skl,n.S_i/∑S_i

Within each apartment group, the costs of energy for heating or cooling of apartments by risers are distributed in proportion to their powers:

N _st,i= N_st,n.P _st,i/∑P _st,i

The balance of the costs of energy for heating or cooling within each apartment group falls on energy for heating or cooling of apartments by radiators: N_r,n — N_sk,n - N_skl,n - N_st,n and is distributed among the apartments in proportion to the power of radiators:

Nr,i — Nr,n.Pr,i/∑Pr,i e) To determine the costs of apartments of the heat necessarily transferred through apartment walls and ventilation, the power of heat transfer is first calculated, which is the sum of the power of heat transfers through walls and the power of conventional heat transfers through ventilation:

P_b,i = P_k,i + P_v,i - power of heat transfers of the apartment

P_k,i = ∑k_i.S_t,i.(t_m,i-t_e,i) - power of heat transfers through exterior walls of the apartment P_v,i = c.mi.kv,i.(t_m,i-t_e,i) - power of conventional heat transfers by ventilation k_i - coefficient of heat transfer of the apartment wall k_v,i = f(p, h) - coefficient of wind speed p - average number of persons in apartments h - above-ground height of the apartment

S_t,i - heat transfer surface area of the apartment wall t_e,i - temperature on the outside of the apartment wall c - specific heat of air m_i = V_i.ρ.b - amount of air transferred by ventilation V_i - volume of the apartment ρ - air density b - average conventional intensity of air exchange

Conventional heat transfers by ventilation are defined by the conventional intensity of air exchange in apartments, the intensity is preferably determined according to hygienic standards, preferably according to the average number of persons in apartments, preferably also depending on the above-ground height of floor according to technical standards.

The exterior walls of the apartment are the apartment walls, which are adjacent to the outdoor environment, adjacent apartments and common areas in the building (corridors, stairs, basements, attics, etc.). f) The costs of heat necessarily transferred through apartment walls and ventilation for individual apartment groups are calculated from the total costs of the group after deducting the costs of energy for heating or cooling of the basement:

Nb.sk, n = Nsk.n " Nskl.n

In each group, these costs are distributed among the respective apartments, preferably according to their heat loss performance

N_b,i = N_{b,sk, n}.P_b,i/∑P_b,i and after adding the shares of the costs of heating or cooling of the basement, the costs of the apartments of heat necessarily transferred through apartment walls and ventilation are obtained:

N_o,i = N_skl,i + N_b,i g) The stated costs are preferably calculated using a uniform initial temperature for all apartments, i.e. without considering the heat transfer through walls between the apartments.

The values according to the project are preferably used as uniform initial temperatures in apartments or even in common areas.

The uniform initial temperature of apartments required to calculate the costs in apartments is preferably determined from the formula for the performance of heat transfers:

However, different levels of heating or cooling of apartments are really the cause of temperature differences between apartments. Therefore, an individual initial temperature can be preferably used for each apartment in the calculation of costs, determined from the balance of heating or cooling power supplied to the apartment by heating or cooling system and heat transfer performance without considering heat transfers through walls between the apartments: t_b,i = (∑k_i.S_t,i.t_e,i + c.m_i.t_e,i.k_v,i + P_st,i + P_r,b,i )/(∑k_i.S_i + c.m_i.k_v,i

The formula for calculating the temperature differences between apartments, including heat transfers through walls between the apartments t_b,i - t_b,i+1 — (((_{P st,i} + P_r,b,i) - (Pst,i+1 + Pr,_b,i+1)).S_t,in,i/∑S_t,in,i)/(C.m_i+k_ex,i.S_t,ex,i + 2. k_{in, i}. S_{t, in, i}) , where St_,in,i refers to the surface area of the wall between the apartments, shows that the actual temperature differences between adjacent apartments are only a fraction of the temperature differences calculated from initial temperatures according to the previous formula.

Therefore, if individual initial calculated temperatures in apartments are used, the heat transfer between apartments are preferably respected and for this purpose a compensated temperature can be accepted as an acceptable simplification of the previous formula (with a maximum error of a few percent) in the calculation of the costs of necessarily transferred heat, which is determined as the average value of the initial temperature of the given apartment and the initial temperatures of adjacent apartments, taking into account the size of apartments: t_b,i,s = ∑t_b,i.S_b,i/∑S_b,i , preferably taking into account the size of walls between adjacent apartments.

Further refinement of the calculation of compensated temperatures in apartments can be preferably achieved by recurrently repeating this calculation using the temperatures from the previous calculation cycle, the temperatures calculated in the previous steps of the current calculation cycle can be also preferably used.

The values of measured air temperatures in rooms or apartments or even in common areas are preferably used in calculation of the costs of the heat necessarily transferred in the apartments. h) Heat transfers between apartments must be also respected in costs, the compensated costs of an apartment are therefore analogously calculated as average values of the total costs of heating or cooling of the given apartment and adjacent apartments, taking into account the size of apartments, both when using measured and calculated individual temperatures:

N_b,i,s — (∑N_b,i.S_m,i/S_m,i)/nb

Further refinement of compensated costs in apartments can be preferably achieved, similarly to the calculation of mean temperatures, by recurrently repeating this calculation cycle using the values from the previous and current calculation cycle. The costs calculated in this way must be converted so that their sum corresponds to the costs of the group:

N_b,i = N_sk.n .N_b,i,s/∑N_b,i,s i) The measurement of air temperatures in apartments independently of other quantities, in particular measurement of energy consumption in radiators, and their use in cost calculation is a necessary condition for being able to consistently assess the different intensity of objective and subjective components of ventilation and other interventions by apartment users in heating or cooling. The costs of the apartments of the heat necessarily transferred through apartment walls and ventilation are calculated with both compensated and measured air temperatures in apartments. The difference between these costs is first deducted from the total costs, an average value of the total the costs of heating or cooling of the apartment and adjacent apartments is calculated from the balance of costs for each apartment, taking into account the size of apartments, and the cost difference is added again to the result, thus calculating the compensated costs of the apartment of heating or cooling.

The new method makes it possible to refine the calculation of costs also from the point of view of different level of thermal resistance of windows and walls in individual apartments. j) The values of compensated costs that exceed the limits set, for example, by law, must be limited for billing. Those parts of compensated costs that exceed the upper cost limit are distributed (calculated) among other apartments in the building, preferably according to the size of apartments and savings, i.e. amounts by which the compensated costs exceed the lower cost limit, are distributed (calculated) among other apartments in the building, preferably according to positive deviations of costs from the lower cost limit, thus determining the resulting costs of heating or cooling.

The new method very thoroughly evaluates the objective technical and natural conditions that affect the costs of heating or cooling in apartments, in particular:

- orientation of apartments, location of apartments at the centre or at the edge of the building,

- dimensions of risers and change of their temperature along their route, unevenness of their dimensioning according to apartment groups,

- heat transfer through all exterior walls of apartments, i.e. also horizontal or vertical walls between adjacent apartments,

- decrease in outdoor temperature depending on floor height,

- heat losses by ventilation continuously depending on floor height and wind speed,

- summer evaporations for evaporating indicators of heat consumption, therefore

- the resulting costs of heating or cooling of apartments can be determined much more precisely by taking these technical and natural effects into account realistically,

- the resulting costs per unit area of apartments are almost the same for all apartment groups, regardless of their orientation, the differences are given only by redistribution of those parts of costs that exceed the limits set by law.

This eliminates the biggest systemic error of current allocation methods - insufficient separation and evaluation of objective and subjective effects in costs of heating or cooling.

By measuring the temperatures in apartments and using them in the calculation of costs, it is possible to further refine the resulting costs of heating or cooling with respect to subjective effects, which include not only different intensity of ventilation but also different level of thermal resistance of windows and walls inside apartments, as well as use of electrical appliances or individual sources of heating or cooling.

In particular, the use of measured temperatures in the resulting costs results in, for example, higher energy consumption for heating or cooling than corresponding to the heat transfers calculated from the measured temperature of the apartment, or lower measured temperature of the apartment than corresponding to the compensated temperature calculated from measured energy consumption for heating or cooling, usually means a higher intensity of ventilation, and thus higher resulting costs.

Or the opposite situation - lower energy consumption for heating or cooling than corresponding to the heat transfers calculated from the measured temperature of the apartment, or higher measured temperature of the apartment than corresponding to the compensated temperature calculated from the measured energy consumption for heating or cooling, usually means lower intensity of ventilation, increased operation of electrical or gas appliances or, for example, improved insulation of apartment walls and thus lower resulting costs.

If the calculation takes into account the individual coefficients of heat transfer according to the specific dispositions in each apartment and provided that the energy consumption for heating or cooling and temperatures in the apartments remain unchanged, then if the user of a better heated or cooled apartment improves the thermal insulation of apartment walls, he/she would be charged higher costs, while reducing the charged costs in adjacent less heated or cooled apartment because it does not get as much heat or cold from warmer or colder apartment.

The heating powers of radiators and risers in all rooms in the apartment have an uncorrected weight in the calculation, thus eliminating the current possibility of misusing the calculation method for reducing the resulting costs by transferring heat from rooms with the most advantageous coefficient of position.

In determining the costs of heating or cooling according to the invention, users are not penalized for technical design of the building and for natural circumstances, as they cannot affect them.

Determining the costs according to the invention creates equal financial conditions for heating or cooling of any apartment, regardless of its position in the building, users will have no reason to blame each other for the position of the apartment. The new method for determining the cost of heating or cooling will no longer distort the market prices of apartments.

The new method may result in equalization or even in decrease of energy consumption within a building with a central distribution of the heating or cooling fluid. It may result in decrease in energy consumption in lower apartments that have taken advantage of the present situation while in the upper apartments set at disadvantage by the present situation an increase in energy consumption may occur.

When using the new method according to the invention, in particular when, in addition to measuring consumption in radiators, the temperature in apartments is completely measured, it makes no sense to intervene administratively by law in calculation of the costs of heating or cooling by apartment-rate determination of the share of basic and consumption cost components or defining upper and lower cost limits. The method for determining the costs of heating or cooling according to the invention can be used:

- also for determining the costs of cooling, despite the difference that in cooling heat flows in the opposite direction than in heating,

- in central and floor heating or cooling systems,

- preferably also for non-residential buildings, whose layout and use correspond to the character of apartment buildings.

The method for determining the costs of heating or cooling according to the invention provides most of the benefits even in the basic version, i.e. without measuring the temperatures in apartments, with minimal demands on additional data compared to existing methods.

At the same time, existing meters and indicators can be used for measuring the energy consumption of heating or cooling equipment; additional data can be obtained from service providers from existing meters installed in domestic or nodal distribution stations. Refinement of the results and increase of the comfort of processing can be then achieved after appropriate addition of technical equipment.

A substantial part of technical data on the construction of a building and apartments can be taken from the documentation that larger allocating companies already have available today. Commonly available computing technology provides enough capacity to quickly process the necessary calculations.

The method for determining the costs of heating or cooling according to the invention can be used not only by cost allocators but also by designers of heating or cooling systems. Overview of figures in drawings

The invention will be further explained on the basis of exemplary embodiments according to the enclosed drawings:

Fig. 1 shows a diagram of the heating system in a building.

Fig. 2 shows graphs of the compilation of the resulting costs of heating in apartments of group 5 by the method according to the invention.

Fig. 3 shows comparative graphs of the resulting costs of heating for groups 1, 2, 3.

Fig. 4 shows comparative graphs of the resulting costs of heating for groups 4, 5.

Fig. 5a-d show comparative graphs of the resulting costs and temperatures without measurement and with measurement of air temperatures in apartments.

Examples of the invention embodiments

Fig. 1 shows a schematic diagram of a heating system in a building with 39 apartments in 5 vertical groups Group 1 to Group 5 and on 8 floors I to VIII. The building is heated by a central heating system. In the basement S, there is a horizontal heating pipe J_, from which vertical distribution pipes branch off, i.e. risers 2, to the radiators 3 in apartments. In order to determine the costs of heating in apartments by the method according to the invention, the heating water temperature in the supply and return pipes 1 in the basement is measured by registration meters 4, 5, consumption in radiators 3 by ratio indicators 6, air temperature in apartments by registration meters 7, air temperature 8 by outdoor registration meter and the total consumption of heat supplied to the building is measured by billing meters 9.

Fig. 2 shows graphically the procedure for determining the costs of heating in apartments of group 5 by the method according to the invention. The values of the resulting costs are defined by the upper cost limit, i.e. 100% above the average value of costs related to the floor area of the apartment, and the lower cost limit, i.e. 80% of the average value of costs related to the floor area of the apartment. The total costs without heat transfer are calculated by adding together

- the shares of apartments in the costs of energy for heating of the basement,

- the costs of energy for heating of apartments by risers, and

- the costs of energy for heating of apartments by radiators, then deducting

- the costs of apartments of heat necessarily transferred through apartment walls and ventilation and then adding average costs related to the floor area of apartments.

The compensated costs with included heat transfer for each apartment are formed by the average value of the total costs for the given apartment and adjacent apartments in the given group 5 and in subgroup 4.

The compensated costs in group 5 do not exceed the upper cost limit, they only exceed the lower cost limit in apartment no. 39, the corresponding cost savings for this apartment are therefore distributed (calculated) among other apartments in the building according to positive deviations of costs from the lower cost limit, thus determining the resulting costs of heating in apartments.

Fig. 3 and 4 show comparative graphs of the resulting costs of heating for groups 1 to 5, according to the invention, according to the direct and indirect degree-day method and according to the division method. The graphs show how significantly distorted results put the current methods of determining the costs of heating against the objective fact by using extremely simplified criteria.

Fig. 5a-d show comparative graphs of the resulting costs and temperatures without measurement and with measurement of air temperatures in apartments determined by the method according to the invention.

Fig. 5a shows a graph of the resulting costs without the measurement of temperatures in apartments, Fig. 5b shows an appropriate graph of the calculated compensated temperatures. Fig. 5c shows a graph of the resulting costs with the measurement of temperatures in apartments, Fig. 5d shows a graph of the measured temperatures and, for comparison, a graph of the calculated compensated temperatures.

The graph illustrated in Fig. 5d shows that a lower air temperature was measured in apartment no. 19 than would correspond to the calculated compensated temperature.

Since the heat consumption in the given apartment and in adjacent apartments in the situation without and with the measurement of temperature is not changed and the temperatures in adjacent apartments corresponded to the compensated temperatures calculated from heat consumption and conventional intensity of ventilation, then the temperature in apartment no. 19 dropped probably due to increased ventilation and the costs of ventilated heat was therefore reflected in the increase in the resulting costs. At the same time, there were heat transfers from these adjacent apartments to apartment no. 19, which were also reflected in the drop in costs in these adjacent apartments.

Claims

1. Method for determining an energy consumption for heating or cooling of apartments in an apartment building especially by means of heat recovered by energetic processing of biomass, natural gas and other conventional fuels, the heating or cooling system of the apartment building comprises meters (6) of energy consumption in radiators (3), temperature meters (4, 5) of heating or cooling distribution system (2) and an outdoor temperature meter (8) wherein in the evaluated period continously or periodically

- the energy consumption in radiators (3) is measured by meters (6) of energy consumption in radiators (3) and the measured data are used for calculation of energy consumption for each apartment,

- the temperatures of the heating and cooling distribution (2) system are measured by means of the temperature meters (4, 5) of heating or cooling distribution system (2) and the measured data are used for calculation of energy consumption in the heating or cooling distribution system (2) for each apartment,

- the outdoor temperatures are measured by means of the outdoor temperature meter (8) and the measured data are used for calculation of the heat consumption transferred through walls and ventilation for each apartment,

- first the total energy consumption for heating and cooling for each apartment is determined by deducting the apartment’s costs of heat necessarily transferred through walls and ventilation from the sum of the apartment’s costs of energy consumed in radiators (3) and heating or cooling distribution system (2) and this difference is added to the average costs of the apartment of heating or cooling, whereupon the compensated costs of the apartment of heating or cooling shall be determined as the average of the total costs of heating or cooling of the given apartment and adjacent apartments, taking into account the size of apartments.

2. Method of claim 1 wherein the costs of the apartment of the heat necessarily transferred through walls and ventilation are calculated from the data of outdoor temperature meter (8) and the compensated temperature in apartments, which is determined as the average value of the initial temperature of the given apartment and the initial temperatures of adjacent apartments.

3. Method of claims 1 and 2 wherein the costs of the apartment of the heat necessarily transferred through walls and ventilation are calculated from the data of outdoor temperature meter (8) and the compensated temperature in apartments, which is determined as the average value of the initial temperature of the given apartment and the initial temperatures of adjacent apartments, taking into account the size of apartments.

4. Method of claims 1 to 3 wherein the costs of the apartment of the heat necessarily transferred through walls and ventilation are calculated from the data of outdoor temperature meter (8) and the compensated temperature in apartments, which is determined as the average value of the initial temperature of the given apartment and the initial temperatures of adjacent apartments, taking into account the size of walls between adjacent apartments.

5. Method of claims 1 to 4 wherein the heating or cooling system comprises air temperature meters (7) in apartments, the costs of the apartment of the energy consumed in the heating or cooling distribution system (2) being calculated from the data of temperature meters (4, 5) of heating or cooling distribution system (2) and from the data of air temperature meters (7) in apartments.

6. Method of claims 1 to 5 wherein the costs of the apartments of the neat necessarily transferred through walls and ventilation are calculated from the data of outdoor temperature meter (8), further being calculated from both the compensated temperatures in apartments and the data of air temperature meters (7) in apartments; the difference between the two costs is first deducted from the total costs, an average value of the total the costs of heating or cooling of the apartment and adjacent apartments is calculated from the balance of costs for each apartment, taking into account the size of apartments, and the cost difference is added again to the result, thus calculating the compensated costs of the apartment of heating or cooling.

7. Method of claims 1 to 6 wherein the values of compensated costs that exceed the limits set, for example by law, are limited by distributing (calculating) those parts of compensated costs that exceed the upper cost limit among other apartments in the building according to the size of apartments, and those parts by which the compensated costs are lower than the lower cost limit among other apartments in the building according to positive deviations of costs from the lower cost limit, thus determining the resulting costs of heating or cooling.