Methodology For Calculating The Energy Performance Of Buildings

Link to law: https://www.riigiteataja.ee/en/eli/ee/MKM/reg/520102014002/consolide
Published: 2013-01-09

Methodology for calculating the energy performance of buildings1

Passed 08.10.2012 Annex 63

This regulation is made in accordance with subsection 73 of section 3 of the Building Act.

Chapter 1

GENERAL PROVISIONS



§ 1. Scope of application of the

Regulation



This regulation establishes the methods for

calculating the energy performance of buildings to prove their compliance with

the minimum requirements for energy performance.

§ 2. Definitions



(1) The

terms in this regulation are defined as follows:

1) major renovation – renovation is deemed to be major if the costs of modification of the

building’s envelope elements and of modification or replacement of the

building’s loadbearing or stiffening elements, or of modification of the

building envelope and the building’s technical systems or parts thereof,

or the complete replacement of a technical system, exceed one quarter of the

average building cost of a construction work that is equivalent to the

construction work which is being renovated;

2) technical systems – the heating system and the system of hot

household water including the corresponding heat sources, the ventilation system,

the cooling system, lighting and the systems which generate heat or electricity

locally and are included in the energy calculation in accordance with this

regulation;

3)

indoor climate control – the use of energy for the purpose of ensuring the quality

of indoor air, including maintaining, increasing or reducing indoor

temperature, in compliance with the ventilation and room temperature

requirements established in this regulation, and for the purpose of lighting

under the building’s standard use;

4) heated area – net area of rooms

with indoor climate control;

5) energy network – a system for the

transmission of energy and for the distribution of energy to consumers (such as

the power network, district heating and district cooling network, natural gas

network);

6) heat gain – solar radiation which

enters the building, as well as internal heat gains from occupants, lighting,

equipment and technical systems;

7)

building leakage rate

– the parameter which characterises the air

tightness of the building envelope and which is determined by means of an air leakage

test at a pressure difference of 50 Pa. The

building’s average leakage rate [m3/(h m2)] is

expressed per square metre of the buildingenvelope. The area of the envelope is

calculated on the basis of the internal dimensions of the building.

8) ESEER – the average cooling

season energy efficiency ratio of cooling and refrigeration equipment issued by

their manufacturer, calculated according to the European standards and on the

basis of the base usage profile and use conditions of an average European

cooling device, excluding the electricity use of the fans and pumps of the

condenser;

9) SEER – the average cooling season

energy efficiency ratio which is stated in the energy performance certificate

of air conditioners and air-to-air heat pumps whose capacity is up to 12 kW and

which is calculated as the ratio of the energy need for cooling during the

cooling season to electricity use under standard conditions;

10) SCOP – the annual average seasonal coefficient of

performance which is stated in

the energy performance certificate of air conditioners

and air-to-air heat pumps whose capacity is up to 12 kW and which is calculated

as the ratio of energy need of heating to electricity use under standard

conditions.

(2) The terms used in this regulation in relation to

energy performance and energycalculation

are defined as follows:

1) test reference year for energy

calculations – the body of outdoor weather data required for

indoor climate and energy calculations and compiled following the Estonian

standard EVS-EN ISO 15927–4:2005 on the basis of weather data collected

in the entire territory of Estonia during the period 1970–2000;

2)

exported energy – the heat or electricity which is generated

within the building or on the building site and which is not used in the

building but is fed into energy networks;

3)

local renewable energy – the heat or electricity generated from solar, wind, water and geothermal energy sources within the building or on the building site. In the

case of heat pumps, the renewable energy harvested from the energy source is

taken into account in the energy calculation according to the heat pump’s

coefficient of performance;

4)

delivered

energy – the electricity obtained from power

networks or the heat obtained from district heating networks in kilowatt-hours

per annum (kWh/y) or the energy content (in kilowatt-hours) of fuel which is

obtained from fuel suppliers and which is used to cover the building’s

annual aggregate energy use in so far as this is not covered by local renewable

energy. Any fuel obtained from the building site is deemed to constitute

delivered energy;

5)

total energy use (kWh/y) of the building – use of heat and

electricity by the building’s technical  systems required for indoor

climate control, the heating of household water and the operation of electrical

equipment, excluding local renewable energy (excepting heat pumps). The

building’s total energy use includes all energy losses of the technical  systems,

including heat sources and the distribution systems of local energy generation,

and the conversion of energy (e.g., coefficient of performance of a heat pump, energy

efficiency ratio of a cooling plant,  cogeneration, fuel cell);

6) primary

energy – the amount of primary energy from

renewable and non-renewable sources which is required for the generation of one

kilowatt-hour of delivered energy, including any losses involved in harnessing

an energy source and in the generation, transmission and distribution of

energy;

7)

energy

carrier conversion factors – factors which take into

account the use of primary energy required for the generation of delivered

energy and the environmental impact involved;

8)

specific

use – the annual energy use in kilowatt-hours per square

metre of heated area of a building [kWh/(m2 y)];

9)

total

weighted specific use of exported energy – the sum of the products,

calculated separately for each energy carrier, of the energy fed into the

corresponding energy network and the energy carrier conversion factor;

10)

total

weighted specific use of delivered energ – the sum of the products,

calculated separately for each energy carrier, of the delivered energy and the

energy carrier conversion factor;

11)

standard

use of a building – the normal use of a building in

relation to the verification of compliance with the minimum requirements for

energy performance. The determination of the standard use takes into account

the building’s purpose of use, its outdoor and indoor climate, the time

during which the building and its technical systems are used, and  heat gains;

12) energy performance indicator [kWh/(m2 y)]– calculated

total weighted specific use of delivered energy consumed in the

course of standard use of the building, from which  the weighted specific use

of exported energy is subtracted;

13) appliances – appliances which belong to the end

user, such as home appliances, electronic devices, office appliances, and which

do not constitute a part of any technical  system;

14) usage profile – the usage rate of

a room, calculated as the ratio of the heat gain from lighting, equipment and  occupants

to the maximum heat gain;

15) specific heat loss of the building envelope [W/K] – specific heat loss via

the building envelope in watts when the difference between outdoor and indoor

temperature is one degree Celsius;

16)

total  specific heat loss of the building envelope per square metre of heated

area [W/(m2K)] – total  specific heat loss via

the building envelope per square metre of heated area of the building at a

difference of one degree Celsius between indoor and outdoor temperature. The

specific heat loss is the sum of the heat losses that result from conduction

and infiltration through the building envelope;

17)

energy

need – the electrical and thermal energy

(without taking into account system losses and conversions from one energy type

to another) required for indoor climate control, the heating of household

water, lighting, and the operation of equipment. The  energy need comprises: 

energy need for space heating, space cooling, the heating of ventilation air,

the cooling of ventilation air, ventilation, the heating of household water,

lighting and the operation of equipment;

18) energy need  for space heating – the amount of thermal energy  required for the

heating of rooms to indoor temperature, taking into account 

heat gains, heat losses that result

from conduction and infiltration through the building envelope and the heating of

ventilation supply air to indoor temperature;

19) energy need for space cooling – the amount of thermal energy required for the

cooling of rooms to indoor temperature, including both latent and sensible heat,

taking into account  heat gain, conduction

and infiltration through the building envelope and the temperature of

ventilation supply air;

20) energy need for the heating of household

water – the amount of thermal energy required for the

heating of household water;

21) energy need for the heating of

ventilation air – the amount of thermal energy required for the

heating of ventilation air to supply temperature, from which recovered heat is

deducted; in the case of a ventilation system without heat recovery, the amount of thermal energy required for the heating of ventilation air from

the outdoor temperature to indoor temperature.

22) energy need for the cooling of

ventilation air – the amount of thermal energy  required for the

cooling of air, including both latent and sensible heat;

23) energy use – use of electrical or

thermal energy at a given point in the system. Energy use is calculated on the basis of energy need,

taking into account system losses and energy conversion losses. At the

end-point of a technical system of the building (usually the connection point

to the corresponding energy network), the energy use of the utility system

equals the sum of delivered energy and local renewable energy;

24) system boundary of delivered and exported

energy – the system boundary which is used in energy

calculation and which determines the relations between the energy flows to be

included in the calculation (Figure 1).

Figure

1. System boundary of delivered and exported energy.



Chapter 2

INPUT PARAMETERS OF THE ENERGY PERFORMANCE CALCULATION



§ 3. Energy calculation



(1) In order to verify the compliance of a building

with the minimum requirements of energy performance, the energy calculation is

performed with respect to the standard use of the building, using the input

parameters which are set out in this regulation and which characterise the indoor

and outdoor climate, the periods of use and operation of the building and the

utility systems, heat gains and the building’s air leakage rate. The other

necessary input parameters are taken from the building design documentation.



(2) For the purposes of the energy calculation, it is

not necessary to perform a detailed division of the building into zones. Small

residential buildings and buildings with a single purpose of use may be

regarded as a single zone for the purposes of the energy calculation. Large

buildings are to be divided into as many zones as required according to their

purposes and periods of use.



(3) In this regulation, the buildings’ purposes

of use are the purposes of use set out in the regulation entitled Minimum

Requirements for Energy Performance enacted in accordance with subsection 72

of section 3 of the Building Act.



§ 4. Outdoor climate



Regardless of the building’s

location, the energy

calculation and the verification of

compliance with the summertime indoor temperature requirement are performed on

the basis of the data of the Estonian test reference year. The test reference

year represents the typical outdoor climate of three decades (1970–2000) and therefore is not suited to be used for the calculation of

the heating power need. Where the test reference year is used for calculating

the cooling load, it should be borne in mind that the results are not

applicable to the cooling load in the case of a warmer than average summer.



§ 5. Indoor climate



(1) The energy calculation uses the indoor temperature

set-points and ventilation air flow rates set out in the regulation entitled Minimum

Requirements for Energy Performance enacted in accordance with subsection 72

of section 3 of the Building Act.



(2) In the case of a simplified calculation which

treats indoor temperature as a constant, the indoor temperature set-points are

used as the indoor temperature value (e.g., in residential buildings 21 °C for

heating and 27 °C for cooling). In the case of a dynamic calculation, the

relevant values are used as the heating and cooling set-points of a thermostat.

Where the building lacks a cooling system, the difference between the

summertime indoor temperatures and the cooling set-point must be calculated.



(3)

Outside of occupied hours, the ventilation air flow rate of a non-residential

building is deemed to be 0.15 l/(sm2) in the out of operation mode of

the ventilation system.

(4) In the case of a variable air

volume ventilation system in which the air flow rate varies and whose control

function operates in accordance with the quality of air (the carbon dioxide (CO2)

content or a combination of CO2 content and, for example,

temperature or humidity values), the air flow rates set out in the regulation

entitled Minimum Requirements for Energy Performance enacted in

accordance with subsection 72 of section 3 of the Building Act are

used as the maximum air flow rates of the relevant rooms. Where a system with a

variable air flow rate is used for the purpose of cooling, the maximum air flow

rate is determined according to the cooling need. The minimum air flow rate and

the ventilation control function must, in general, be selected such as to avoid

exceeding the 1000 ppm maximum volume fraction of CO2 while the

corresponding value in outdoor air is 400 ppm.





Chapter 3

STANDARD USE OF THE BUILDING



§ 6.Occupied hoursand  heat gain

(1) The standard use of buildings and the

corresponding heat gain from appliances and lighting and from occupants are

provided in Table 1 which shows the building’s number of occupied hours

per 24-hour day, the number of days of use per week and the maximum heat gain from

lighting and appliances and the maximum heat gain from occupants during the

building’s occupied hours. The heat gain figures do not include heat gain

from the building’s technical  systems, which is calculated as part of

the calculations made for the technical  systems according to the requirements

set out in Chapter 5 of this regulation.

Table 1. Standard use of buildings and the

corresponding maximum values of  heat gain per square metre of heated area

Building’s purpose of use



Occupied hours



Usage rate



Lightinga

W/m2



Appliances

W/m2



Occupantsb

W/m2



Occupants

m2/person



Hours



h/24h



d/7d



Small residential building



00:00-00:00



24



7



0.6



8c



2.4d



2



42.5



Multi-apartment building



00:00-00:00



24



7



0.6



8c



3d



3



28.3



Office building, library or research building



07:00-18:00



11



5



0.55



12



12



5



17.0



Commerce building or  terminal



07:00-21:00



14



7



0.55



20



1



5



17.0



Accommodation building





00:00-00:00



24



7



0.5



8



1



4



21.3



Food service building or service building



12:00-22:00



10



7



0.4



20



4



14



6.1



Public building



08:00-22:00



14



7



0.5



14



0



5



17.0



Educational buildinge



08:00-16:00



8



5



0.6f



15



8



14



5.4



Pre-school institution for children



07:00-19:00



12



5



0.4



15



4



20



3.8



Healthcare building



00:00-00:00



24



7



0.6



9



4



8



10.6



a the figures shown assume the use, in non-residential

buildings, of fluorescent lights or other lighting equipment of similar

effectiveness. The heat releases shown include both the nominal power of the

fluorescent light and the nominal power of the starter which accounts for

approximately 25% of the nominal power.

b the internal heat gain from occupants only includes

the sensible heat. In order to include latent heat, the relevant values must be

divided by the factor 0.6.

c the usage rate of lighting in residential buildings

is 0.1.

d to obtain the electricity use of the appliances in

residential buildings, the heat release value must be divided by the factor

0.7.

e excluding pre-school institutions for children.

f during the summer break from 15 June to 15 August,

the usage intensity is 0.1 and the ventilation operates in the non-use-hours

mode.

(2) Usage rate means the average use intensity of

lighting and appliances and the average presence of occupants during the

building’s occupied hours. The maximum heat release value (usage rate =

1) is used in the calculations of summertime indoor temperatures and cooling loads,

except in the case of buildings referred to under subsections 8 and 9. For the

purposes of the energy calculation, the maximum heat release value is

multiplied by the usage rate value. The annual heat release Q [kWh/(m2y)]

of lighting and appliances and the internal heat gain from occupants is

calculated using the following formula:
where k is the rate of usage;

P

is heat release W/m2;

τd is the building’s number of occupied hours per

24-hour day;

τw is the building’s number of days of

occupancy per week.



(3) For the purposes of the energy calculation, the use

of electricity by lighting and appliances equals the heat released by the

lighting and appliances. In residential buildings, the use of electricity by

appliances is obtained by dividing the heat release of appliances with the

factor 0.7.



(4) Lighting which is characterised by wattage lower

than that given in Table 1 may be used if it provides the same level of

illuminance and a separate calculation of illuminance in standard rooms is

provided as part of the input parameters of the energy calculation. The general

index of illuminance in rooms, uniformity of illuminance, glare and colour

rendition and other lighting-related guidelines are provided in the standard

EVS-EN 12464-1.



(5) Where the building’s lighting is controlled

on a demand basis, the number of use hours of the lighting is calculated using

the occupied hours shown in Table 1. The model used for the calculation of the average

wattage of lighting must be room-based and the lighting of rooms must ensure

the level of illuminance which corresponds to the relevant purpose of use.

Where the calculation of the average wattage of lighting is performed in

respect of different room types, the average wattage of lighting in heated

areas is the weighted average of the areas of the rooms which represent those

types.

(6) In calculating the ventilation need,

ventilation is held to start one hour before the building’s start hour of

use and to switch to the non-use-hours mode one hour after the end hour of use

of the building (except for buildings which are used on a 24 hour basis).

(7) The dynamic energy calculations of

residential buildings, office buildings, libraries, research buildings,

educational buildings (excluding pre-school institutions for children and other

educational buildings), and pre-school institutions for children use the

detailed usage profiles of buildings set out in Table 2 below.

Table 2. Detailed usage

rate  values for the energy calculation

Time



Residential building, lighting





Residential building, lightning





Residential building occupants





Office building,

library, research building



Educational building



Pre-school institution for children



00:00-01:00



0



0.5



1



0



0



0



01:00-02:00



0



0.5



1



0



0



0



02:00-03:00



0



0.5



1



0



0



0



03:00-04:00



0



0.5



1



0



0



0



04:00-05:00



0



0.5



1



0



0



0



05:00-06:00



0



0.5



1



0



0



0



06:00-07:00



0.15



0.5



0.5



0



0



0



07:00-08:00



0.15



0.7



0.5



0.2



0



0.4



08:00-09:00



0.15



0.7



0.5



0.6



0.6



0.8



09:00-10:00



0.15



0.5



0.1



0.6



0.6



0.8



10:00-11:00



0.05



0.5



0.1



0.7



0.6



0.3



11:00-12:00



0.05



0.6



0.1



0.7



0.4



0.3



12:00-13:00



0.05



0.6



0.1



0.4



0.3



0.8



13:00-14:00



0.05



0.6



0.2



0.6



0.6



0.1



14:00-15:00



0.05



0.6



0.2



0.7



0.6



0.1



15:00-16:00



0.05



0.5



0.2



0.7



0.3



0.4



16:00-17:00



0.2



0.5



0.5



0.6



0



0.3



17:00-18:00



0.2



0.7



0.5



0.2



0



0.3



18:00-19:00



0.2



0.7



0.5



0



0



0.3



19:00-20:00



0.2



0.8



0.8



0



0



0



20:00-21:00



0.2



0.8



0.8



0



0



0



21:00-22:00



0.2



0.8



0.8



0



0



0



22:00-23:00



0.15



0.6



1



0



0



0



23:00-00:00



0.15



0.6



1



0



0



0



(8)

The verification of compliance of residential buildings

and open office rooms with the summertime indoor temperature requirement is

performed using the detailed energy calculation usage profiles

of buildings as set out in Table 2.



(9) The verification

of compliance of single room offices, conference rooms, classrooms and the

rooms of pre-school institutions with the summertime indoor temperature

requirement and the dynamic calculation of the cooling load of such premises are

performed using the detailed usage profiles of rooms as set out in Table 3. For

classrooms and conference rooms, the  heat gain values provided in Table 4 are

used. For other rooms, the  heat gain values provided in Table 1 are used.



Table 3. Usage rate values for the verification of

compliance with summertime indoor temperature requirement

Time



Single-room office



Conference room



Classroom



Playing room in a pre-school institution for

children



Sleeping room in a pre-school institution for

children



00:00-01:00



0



0



0



0



0



01:00-02:00



0



0



0



0



0



02:00-03:00



0



0



0



0



0



03:00-04:00



0



0



0



0



0



04:00-05:00



0



0



0



0



0



05:00-06:00



0



0



0



0



0



06:00-07:00



0



0



0



0



0



07:00-08:00



0



0



0



0.5



0.2



08:00-09:00



1



1



0.8



1



0.2



09:00-10:00



1



1



0.8



1



0.2



10:00-11:00



1



1



0.8



0.4



0.2



11:00-12:00



1



1



0.8



0.4



0.2



12:00-13:00



0



0



0.5



1



0.2



13:00-14:00



1



1



0.8



0.2



1



14:00-15:00



1



1



0.8



0.2



1



15:00-16:00



1



1



0.8



0.5



0.5



16:00-17:00



1



1



0



0.4



0.2



17:00-18:00



0



0



0



0.4



0.2



18:00-19:00



0



0



0



0.5



0.2



19:00-20:00



0



0



0



0



0



20:00-21:00



0



0



0



0



0



21:00-22:00



0



0



0



0



0



22:00-23:00



0



0



0



0



0



23:00-00:00



0



0



0



0



0



Table 4. Internal  heat

gain values for the verification of compliance with summertime indoor

temperature requirement

Purpose of use of

the room



Lighting

W/m2





Appliances

W/m2





Occupants

W/m2





Occupants

m2/person





Conference room



15



50



25



3.4



Classroom



15



12



35



2.1



Computer class



15



75



35



2.1



(10) In dynamic calculations, the total internal

heat gain from one occupant is taken to amount to 125 W (sensible heat 85 W).

In educational buildings, including pre-school institutions for children, the

total internal heat gain fromoccupants is held to amount to 110 W (sensible

heat 75 W) per occupant. These values correspond to 1.2 and 1.0 metabolic units

(met), with body surface area amounting to 1.8 m2. The thermal

resistance of clothing is held at 1.1 clo in wintertime and 0.6 clo in summertime.

The  heat gain from occupants is calculated in relation to heated area using

the  heat gain values given in Table 1 in respect of occupants.

§ 7.Domestic hot water use



For

the specific use of hot household water, the figures to be used are given in

Table 5 in litres per square metre of heated area per annum. The temperature

difference between hot and cold water is taken to amount to 50°C.



Table

5. Specific use of hot household water and energy need per square metre of

heated area

Building’s

purpose of use



Specific use of hot water

l/(m2 y)





Energy need

kWh/(m2 y)





Small residential

buildings



430



25



Multi-apartment

buildings



520



30



Office buildings,

libraries and research buildings



100



6



Commerce buildings

and terminals



65



4



Accommodation

buildings



520



30



Food catering and

service buildings



400



23



Public buildings



340



20



Educational

buildings (excl pre-school institutions for children)



180



10



Pre-school

institutions for children



460



27



Healthcare

buildings



520



30



§ 8. Stoves, fireplaces and sauna stoves

(1) The stoves and fireplaces may be

included in the energy calculation as part of a combined heating system,

provided the fireplaces store heat and are equipped with a combustion air duct.

Fireplaces which do not store heat and which use indoor air for combustion are

not included in the energy calculation. Stoves which use indoor air for

combustion are not included in the energy calculation. Where stoves are used as

the main heating system, they are included in the energy calculation regardless

of whether or not they have a combustion air  duct.

(2) In calculating the heat release of the stoves

and fireplaces which are taken into account in the energy calculation those

stoves and fireplaces are deemed to be heated once every 24 hours.

(3) Wood-burning sauna stoves are not

included in the energy calculation. The electricity use of electric sauna stoves

of small residential buildings and apartments is deemed to amount to 500 kWh

per year. The heat release of electric sauna stoves is not taken into account

as  heat gain.

§ 9. Air leakage of buildings

Where the building’s air leakage rate

has not been measured or proved in any other manner, the energy calculation

uses the base values of air leakage of buildings given in Table 6. Where the

design air leakage value is greater than the base value in Table 6, the design

air leakage value is used. Where air leakage is measured according to the

standard EVS-EN 13829 or has been proved by the supplier of the house, the

measured or proved value is used in the energy calculation.

Table 6. Base

values of air leakage of buildings per square metre of building envelope.

Purpose of use



Base value of air leakage m³/(hm²)



New building, major renovation



Renovation, existing building



Detached houses



6



9



Other buildings



3



6



Chapter 4

CALCULATION OF ENERGY NEED

AND SUMMERTIME INDOOR TEMPERATURES



Division 1

Calculation of energy need

§ 10. Principles of calculation of energy

need and summertime indoor temperatures

(1) The calculation of energy need follows

the principles of the standard EVS-EN ISO 13790 which are applied in accordance

with this section.

(2) The calculation of the energy need for space

heating takes into account the need to heat infiltration air and the heating of

ventilation supply air in the room from supply air  temperature to indoor

temperature.

(3) When calculating the energy need for the

heating of ventilation air, the heat recovery of the ventilation system is

taken into account. The energy need for the heating of ventilation supply air

includes the heating of the ventilation air before and/or after heat recovery

or, in ventilation systems without heat recovery, the heating of the supplied

outdoor air from the outdoor temperature to indoor temperature.

(4) Heat gain is calculated following the

requirements specified in section 6. The calculation of solar radiation which

enters the building through glass surfaces takes into account different solar

protection solutions (such as solar protection glass, internal and external

window blinds, grates, awnings) as provided in the design solution, as well as

the shadows cast on glass surfaces by surrounding objects and by parts of the

building itself.

(5) The energy need for the heating of household

water is calculated in accordance with section 7. 

(6) The parameters set out in section 6 are

used in calculating the summertime indoor temperature and the energy need for space

cooling. The cooling of rooms by air

change achieved through the opening of windows is not taken into account in the

calculations  for non-residential buildings. In the case of residential

buildings, only the opening of windows to the airing position and the air

change driven by the difference between outdoor and indoor temperature are

taken into account (the windows are closed when the temperature falls to the

heating set-point). The verification of compliance with the summertime indoor

temperature requirement provided in the regulation entitled Minimum

Requirements for Energy Performance established in accordance with subsection

72 of section 3 of the Building Act takes into account the fact that

the degree hours requirement applies to the occupied hours of the building and that

outside those hours the indoor temperature may be higher, but will not be taken

into account.

Division 2

Calculation of heat loss through the building

envelope



§ 11. Principles of calculation of

heat loss through the building envelope

(1) In the calculation of heat losses, the area of the building envelope is calculated on the

basis of internal dimensions of the building (the dimensions between

internal surfaces of walls or ceiling and floor together with rooms and

load-bearing and non-load-bearing partitions). Where heat losses are calculated

separately for each room, the area of the relevant envelope section is

calculated using the centre-line measures of partitions and inserted ceilings.

(2) The heat losses of the building

envelope (exterior walls, floors and roofs) are calculated on the basis of the

thermal transmittance of the envelope and its area as calculated on the basis

of the internal dimensions of the building. Regular thermal bridges (e.g.,

stiffeners, masonry anchors) are taken into account in accordance with their

thermal transmittance values. The heat losses of  irregular thermal bridges

(e.g., the junctions of exterior wall and exterior wall, exterior wall and inserted

ceiling, floor and exterior wall, warm roof and exterior wall, as well as window to wall fixing junctions) are taken into account separately in

accordance with the thermal transmittance values of linear and point thermal

bridges. If necessary, the total specific heat loss (heat loss in watts at a

temperature difference of one degree) of the building envelope calculated

according to the method

described above is converted into average thermal transmittance of the building

envelope by dividing the total specific heat loss of the envelope with the area

of the envelope which is determined according to the rules of the calculation

software used.

(3) The thermal transmittance of the

building envelope is based on the data obtained from the building design

documentation. The specific thermal conductivity of materials should be

calculated according to the standard EVS-EN ISO 10456:2008 and the thermal

resistance of homogeneous and non-homogeneous material layers according to the

standards EVS-EN ISO 6946 and EVS 908-1.

(4) The building’s heat loss to the

ground is determined on the basis of a dynamic one-dimensional calculation

which assumes a heat-accumulating soil layer whose thickness is at least one

metre and below which the temperature remains constant at 7 °C, or on the basis

of a dynamic three-dimensional calculation, or by using tabulated values of the

temperature of the ground beneath the building, or according to the standard

EVS-EN ISO 13370. Where more precise data are unavailable, the following parameters

may used in for calculation purposes: for drained surfaces, specific thermal

conductivity 1.4 W/(m K) and specific heat 1.5 MJ/(m3K); for

undrained surfaces, specific thermal conductivity 2.0 W/(m K) and specific heat

2.0 MJ/(m3K); for homogeneous rock, specific thermal conductivity

3.0 W/(m K) and specific heat 2.0 MJ/(m3K).

§ 12. Thermal

bridge calculation

(1) The thermal transmittance values of

thermal bridges are obtained from the building design documentation. The

thermal transmittance of thermal bridges should be calculated using either the

detailed or simplified method in accordance with the corresponding standard

(e.g., EVS-EN ISO 10211, EVS-EN ISO 10077, EVS-EN ISO 14683, ISO 15099), or the

thermal transmittance values provided by the manufacturer of the material or

construction product. Where more precise data are unavailable, the values

provided in Table 7 may be used in respect of residential buildings.

Table 7. Thermal

transmittance values of linear thermal bridges of the building envelope





Thermal transmittance of linear thermal bridges ,

W/(m·K)



New buildings



Buildings undergoing major renovation



Buildings undergoing renovation



Existing buildings



External

corner of an exterior wall



0.2



0.3



0.5



1.0



Internal

corner of an exterior wall



-0.1



-0.2



-0.2



0.3



Junction

of an exterior and an interior wall



0.1



0.1



0.2



0.9



Junction

of an exterior wall and an inserted ceiling



0.1



0.2



0.3



0.8



Junction

of the roof and an exterior wall



0.2



0.2



0.4



0.4



Junction

of an exterior wall and the slab floor  



0.3



0.3



0.4



0.4



Junction

of an exterior wall and the  floor  above vented crawl space



0.3



0.3



0.4



0.4



Junction

of a window and an exterior wall (window

in the insulation layer, its frame covered with insulation which amounts to

at least 40% of the total thickness of the insulation layer)





0.1



0.1



0.2



0.2



Junction

of a window and an exterior wall (window in the load-bearing layer)



0.2



0.3



0.4



0.5



Junction

of a balcony and an exterior wall



0.3



0.5



0.6



0.8



(2) The thermal

transmittance ΔΨ (W/K) of the thermal bridges of the building

envelope is calculated by means of the following formula:
where

Ψj is the thermal transmittance of the linear thermal

bridge in W/(mK);
ljis the length of the linear thermal bridge in metres;
χp is the thermal transmittance of the point thermal

bridge in W/K;
np is the number of similar point thermal bridges in the building

envelope.

(3) The thermal transmittance of windows Ua (W/(m2K)) is obtained from the data provided by the manufacturer.

Where no such data are available, thermal transmittance is calculated using the

detailed method provided in the standards (for example, EVS-EN ISO 10077 or

EVS-EN ISO 15099) or by means of the following simplified formula:


where Uk

is the thermal transmittance of the glazing in W/(m2K);
Ak is the area of the glazing in m2;
Ur is the thermal transmittance of the frame and the sash in W/(m2K);
Ar is the area of the frame and the sash in m2;

Ψk is the thermal transmittance of the linear thermal

bridge of the glazing unit (largest perimeter of the visible limit of the glazed

area) in W/(mK);

lk is the length of the perimeter of the glazing unit in metres.

(4) The thermal transmittance of the glazing

and frame and the parameters of the linear thermal bridge of the glazing unit are

obtained from the data provided by the manufacturer. If more precise data are

unavailable, the thermal transmittance of the frame unit is held at 1.6 W/(m2K)

in the case of plastic windows; at 1.7 W/(m2K) in the case of timber

windows whose frame and sash unit are 70 mm thick; 1.7 W/(m2K) in

the case of timber-aluminium windows whose frame and sash unit are 110–130

mm thick; 1.1 W/(m2K) in the case of timber-aluminium windows whose

frame is 130 mm thick and whose sash is 170 mm thick; 4.0 W/(m2K) in

the case of metal profiles with a thermal break; 7.0 W/(m2K) in the

case of metal profiles without a thermal break.

(5)

The thermal resistance of the frame and sash unit of timber windows may be

calculated as the thermal resistance of a layer which consists of homogeneous

material with an average thickness of the frame and sash unit and which is

multiplied by the factor 0.7 to account for two-dimensional heat conduction.

(6)

Where more precise data are unavailable, the linear thermal bridge of the glazing

unit is taken to be 0.06W/(mK); in the case of plastic and timber

windows, 0.08W/(mK); in the case of metal profiles without

a thermal break; 0.02W/(mK); in the case of metal profiles with

a thermal break.

Division 3

Infiltration



§ 13. Determination of the infiltration air flow rate



(1)

The infiltration air flow rate qi (l/s) is calculated by means of

the formula:

where

q50is the average air leakage rate in m3/(h·m2)

of the building envelope, calculated in accordance with section 9 of this

regulation;
A is the area of the building envelope (including floors) in m2;
x is the factor which is 35 in the case of a single-storey building, 24

in the case of a two-storey building, 20 in the case of a three or four-storey

building and 15 in the case of a five-storey or higher building, the height of

a storey being 3 metres;
3,6 is the factor which converts the airflow rate unit from m3/h

to l/s.

(2)

Where exhaust  air flow rate exceeds supply air flow rate, the infiltration air

flow rate may be calculated by means of the following formula:

where

q50 is the average air leakage rate in m3/(h·m2)

of the building envelope, calculated in accordance with section 9 of this

regulation;
A is the area of the buildings envelope in m2;
qv is the exhaust air flow rate in l/s;
qs is the supply  air flow rate in l/s.

(3)

Where the formulae set out in subsections 1 and 2 are used simultaneously, the

infiltration air flow rate is determined on the basis of the formula which

yields the lower air flow rate.





Chapter 5

RULES FOR THE CALCULATION OF THE ENERGY USE

OF THE BUILDING’S TECHNICAL SYSTEMS



Division 1

Heating systems



§ 14. Principles of calculations concerning heating systems



(1) The calculations concerning heating

systems include the calculation of the energy use for space heating, of the

heating of ventilation air and of household water. The corresponding energy use

(kWh/y) values are calculated on the basis of the relevant energy need. Rather

than totalling the use of heat and electricity, these are treated separately in

order to make it possible to calculate use figures by source of delivered

energy.



(2) The use of electrical and thermal

energy by a heating system is calculated on the basis of the efficiency of the

heating system (or, where a heat pump

system is used, that system’s coefficient of performance) and of the electricity use

of any auxiliary devices. The inclusion in the calculation of

the efficiency factor of the heating system allows losses in the thermal energy

source (e.g., losses in the boiler or the heat exchanger of the district

heating system) as well as losses related to the distribution and output of

heat and to inaccuracies in regulating room temperature to be taken into

account. The energy use of the heating system is obtained by dividing its energy

need by its efficiency factor. The efficiency factor of the heating system is

obtained as the product of the efficiency factor of the thermal energy source

and the efficiency factor of the distribution and output of heat. In heat pump

systems, the coefficient of performance is used instead of the efficiency

factor. The efficiency factor of the thermal energy source is calculated on the

basis of the data provided by the manufacturer; the efficiency values provided

in Table 8 may be used instead of the calculated value. The efficiency of the

distribution and output of heat and the electricity use of auxiliary devices

are calculated using a computer simulation; the parameters provided in Table 9 may

be used instead of the calculated value. Where the radiators of the system are

not equipped with thermostatic valves, the efficiency values listed in Table 9 are

reduced by 0.1 units.



Table

8. Efficiency factors of thermal energy sources on the basis of the lowest

calorific value of the consumable substance of the fuel

Thermal energy source



Efficiency factor



District heating

substations



1.0



Oil or gas boilers



0.85



Oil, condensing boilers



0.90



Gas, condensing boilers



0.95



Pellet boilers



0.85



Other types of solid fuel

boilers



0.75



Electric boilers



1.0



Stoves



0.6



Table 9. Efficiency factors of the distribution and

output of heat and the electricity use of auxiliary devices

Building type



Manner of heating



Efficiency factor



Electricity use of the

circulation pumps of hydronic systems1, kWh/(m2 y)



Small residential buildings



Radiators



0.97



1







Floor heating slab floors or floors above

vented crawl space



0.85



2







Floor heating in inserted

ceiling



1.0



2







Ceiling heating in a warm

roof



0.90



2







Ceiling heating in an

inserted ceiling



1.0



2



Other buildings



Radiators



0.97



0.5







Floor heating slab floors or floors above

vented crawl space



0.85



1







Floor heating in inserted

ceiling



1.0



1



1 electricity use per square metre of heated area, in

the case of electric radiators, cables and electric ceiling heating and heat

pump systems, kWh/(m2 y)



(3) The losses of the heating system and the

electricity use of auxiliary devices are not taken into account as internal

heat gain in the energy calculation. The losses accounted for in the efficiency

factor of the heating system are not utilisable.



§

15. Calculations concerning heating systems incorporating

heat pump systems



(1) The calculation concerning the heat pump system is

based on the coefficient of performance that shows how many kWh of thermal

energy are obtained for each kWh of electrical energy consumed by the heat

pump.



(2) A heat pump operated as part of a combined heating

system is taken into account in the calculation if a part of the peak thermal power

need is satisfied by another heat source (e.g., an electric heating element or an

oil or gas-fired boiler). Geothermal heat pumps which produce thermal energy

from water or ground energy may satisfy the entire thermal power need or a part

of it. Other heat pumps are always considered part of a combined heating

system.



§ 16. Calculations

concerning combined heating systems incorporating heat pump systems



(1) In

combined heating systems, the heat generated by the heat pump is calculated on

the basis of the heat pump’s thermal capacity, instant heating need and

the heat gain which reduces heating need in accordance with section 6. With

respect to space heating and the heating of ventilation air, the instant power

need (which for the purposes of this subsection does not mean the dimensioning capacity

of the heat pump system) depends on the outdoor temperature.



(2) The

thermal power need of the heating system is calculated for each hour. The

thermal energy produced by the heat pump (kWh/y) is the sum of the power needs

of the hours during which the capacity of the heat pump exceeds or equals the power

need (calculated for each hour of the test reference year). The calculation

takes into account the reduction of peak capacity as a function of the drop in

outdoor temperature and the calculations are conducted for the relevant

temperature ranges.



(3) The

thermal energy produced by another source of such energy (kWh/y) consists of

the power need that is not covered by the heat pump and is calculated as the

sum of the differences between the power need and the heat pump’s power (for

each hour of the test reference year, taking into account the fact that the power

of the heat pump is equal to or less than the power need of the heating system).

The energy use of the other source of thermal energy is calculated in

accordance with the requirements set out under subsection 2 of section 14.



(4) To

calculate the use of electrical energy by the heat pump system, the thermal

energy produced by the heat pump is divided by the average coefficient of

performance which characterises the heat pump system during the heating period,

and which accounts for the electricity use of the circulators and any other

auxiliary devices connected to the heating system, as well as, in accordance

with section 14, the efficiency factor of the distribution and emission of heat.

The coefficient of performance is determined on the basis of the values set out

in Table 10 or of the calculation performed using data provided by the

manufacturer, which account for the operation of the heat pump at part load and

at different outdoor temperatures. When using the data set out in Tables 9 and

10, the average coefficient of performance of the heat pump system equals the

product of the coefficient of performance value set out in Table 10 and the

efficiency factor value set out in Table 9.



Tabel 10. Average values of

the coefficient of performance of heat pumps for the heating period and for the

heating of household water1

Type of heat pump



Average coefficient of

performance for the heating period2



Performance coefficients at

different outdoor temperatures (°C) and different part load values (%)

-15°C/100%; -7°C/100%;

2°C/50%; 7°C/50%



Geothermal heat pump, Geothermal heat pump,

40°C/33°C





3.6



3.4

 



Geothermal heat pump,

5°C/35°C

Geothermal heat pump,

50°C/35°C





3.2



3.0

 



Geothermal heat pump, heating

of household water



2.7

 



Exhaust air heat pump3



3.0

 



Air-to-air heat pump4



-



        2.0            

2.4             3.0             4.0



Air-to-water heat pump,

40°C/33°C4



-



        1.7            

2.1             2.7             3.5



Air-to-water heat pump, heating

of household water



2.0

 



1 The coefficient of performance accounts for the use

of electricity by the pump unit, circulators and auxiliary devices.

2 In relation to the heating of household water the

coefficient of performance reflects the year’s average value.

3 The temperature difference of exhaust air before and

after entering the heat pump amounts to 21-5=16 °C and a part of the heat pump

capacity is utilised for the heating of household water.

4 The capacity and the coefficient of performance of

the heat pump depend considerably on the outdoor temperature.



(5) In the

case of heat pumps which extract thermal energy from outdoor air the

calculation of electrical energy use is performed separately for the relevant

temperature ranges. With respect to air-to-air heat pumps whose capacity is up

to 12 kW the calculation of electrical energy use may be performed using the

yearly average coefficient of performance which for the present purposes is to

be found in the energy performance certificate of the heat pump as the SCOP

value corresponding to the coldest climate zone. The use of SCOP value requires

that the air-to-air heat pump is dimensioned to a load that corresponds to the

oudoor temperature of -7 °C.





Division 2

Ventilation systems



§ 17. Calculation of air

flow rates of ventilation systems



(1) For the purpose of using it in the energy

calculation, the value of the outdoor air flow rate of the building’s

ventilation system is calculated according to the regulation entitled Minimum

Requirements for Energy Performance established in accordance with

subsection 72 of section 3 of the Building Act. Heat recovery and the

electricity use of the ventilation system are calculated for ventilation units that

correspond to those described in design documentation and produce the air flow

rate described in the previous sentence (ventilation units which correspond to those

described in design documentation have sufficient capacity to guarantee the

required air flow rates). The calculation takes into account the possible

difference in the flow rates of supply and exhaust air, both with respect to

the given ventilation unit and in the case of separate fans. Where the volume

of exhaust air exceeds the volume of supply air, the difference between the

exhaust and supply air flow rates is regarded as an additional supply of

outdoor air without heat recovery.



(2) The energy use of ventilation units whose hours of

operation differ is calculated separately. The air flows of ventilation units

with identical hours of operation are usually totalled.



(3) The

infiltration air flow is not included in the air flow calculation of the

ventilation system and is calculated separately according to section 13, which

makes provision for accounting for the possible difference between the supply

and exhaust air flow rates by introducing the corresponding adjustment in the formula

of the infiltration air flow rate.



§ 18.

Calculation of heat recovery



(1) Heat recovery

in the ventilation system is calculated simultaneously with the energy need for

space heating and for the heating of ventilation air.



(2) The

calculation of heat recovery is based on the temperature ratio value of the

heat exchanger (the difference between the temperature of the heated  air stream

before and after the heat exchanger divided by the maximum temperature

difference over the heat exchanger), the temperature of supply air and the measures

designed to limit frost formation on the heat exchanger. Where

manufacturer’s data are unavailable, the following ratios are used:

1) cross-flow plate heat exchangers, 0.6;

2) counterflow plate heat exchangers, 0.7;

3) rotary heat exchangers, 0.7;

4) run-around coil

heat exchangers, 0.4.



(3) In order to avoid frost growth on the heat

exchanger at low outdoor temperatures, the minimum temperature of exhaust air

(the air leaving the ventilation unit) is usually controlled by reducing the efficiency

of the ventilation unit. Where more precise data are unavailable, the minimum

temperature of exhaust air is controlled as follows:

1) in residential buildings, to +5 °C in the case of a

plate heat exchanger and to 0 °C in the case of a rotary heat exchanger or a

plate heat exchanger with humidity recovery;

2) in other non-residential buildings without humidification and significant humidity

production, to 0 °C in the case of a plate heat exchanger and to –5 °C in

the case of a rotary heat exchanger.

(4) The additional

power need and energy which are required for avoiding frost formation

on the heat exchanger are included in the calculation concerning the ventilation

system.



(5) In order to avoid the overheating of rooms, the

temperature of supply air is set below the indoor temperature. In systems in

which the temperature of supply air is kept constant, it is usually set at 18

°C. The heating of supply air to the indoor temperature is included in the

calculation of the energy need for space heating.



§ 19.

Calculation of the electricity use of ventilation systems



(1) The electricity use of a ventilation system mainly

consists of the electricity use of the ventilation units and their control

devices and to a lesser extent of the electricity use of pumps and other

auxiliary devices. The efficiency of electricity use is assessed on the basis

of specific fan power of the ventilation system at a calculated air flow rate. Specific

fan power is the ratio of the total power of the system to the air flow rate

(either supply or exhaust air flow rate, the higher to be selected) [(kW/(m3/s)].



(2) In the case of bigger ventilation units (air flow

rate over 0.25 m3/s), electricity use is calculated separately in

respect of each fan. The electricity use of a fan Ev (kWh/y)

is calculated by means of the following formula:

where Pv

is the wattage of the fan in kW;
τdis the number of the operating hours of the fan at a

calculated air flow rate per 24-hour period;
τw is the number of the fan operating days per week at a

calculated air flow rate d;
t is the period of 8760 hours in respect of which the calculation is

performed.



(3) The wattage of

the fan Pv (W) is calculated by means of the following

formula:

where Δpvis the fan pressure rise in Pa;
V is the fan’s air flow rate in m3/s;
ηft is the fan’s total efficiency which includes

the efficiency of the fan, the efficiency of the belt transmission, the efficiency

of the motor and the efficiency of the control of the possible rotation speed.



(4) The total  efficiency

of the fan is obtained from the data provided by the manufacturer; the values

set out in Table 11 may be used instead of relying on the manufacturer’s

data.



Table 11.

Aggregate efficiency ηft of the fan

Air flow V m3/s



ηft







0.20



0.25 – 0.5



0.35



0.5 – 1



0.40



1 – 5



0.45



> 5



0.50



§ 20. Calculation

concerning the pressure rise of the fan



(1) The

pressure rise of the fan Δpv (Pa) is calculated by means

of the following formula:



Δpv = Δpm

+ Δpt,



where Δpmis the pressure drop of the ventilation unit in Pa;
Δptis the pressure drop of the ducts in Pa.



(2) The

pressure drop of the ventilation unit Δpm includes the

total pressure drop of the unit’s components and the pressure drop at the

juncture of the fan and the ventilation unit. The pressure drop of filters is

deemed to equal the average pressure drop over their period of use, to be

calculated by adding to the initial pressure drop one third of the difference

between the final and initial pressure drop values.



(3) The

pressure drop of ducts Δpt represents the total pressure

drop of the ducts and of the terminal devices, including the pressure drop in

the ducts leading both to and from the ventilation unit.



(4) Where

no data are available in the building design documentation concerning the pressure

drop values, those values are calculated using the data set out in Table 12.



Table 12. Pressure drop values for ventilation units and duct

segments in systems whose air flow rate is ≥ 0,25 m³/s. The terminal

surface velocity of ventilation unit components corresponding to low, normal

and high pressure drop values is, respectively, 1.5, 2 and 2.5 m/s.

Component



Pressure drop in Pa



Supply



Low



Normal



High



Heating element



40



80



120



Cooling element



60



100



140



Heat recovery unit



100



150



200



Coarse filter



30



60



100



Fine filter



70



100



200



Noise suppressor



30



50



80



Juncture of ventilation

unit and ducts



20



50



70



Ducts:

   

 

 



-constant air flow

rate



100



200



300



-variable air flow rate



200



300



400



Terminal device



50



50



100



Exhaust



Low



Normal



High



Heat recovery unit



100



150



200



Filter



50



100



150



Noise suppressor



30



50



80



Juncture of ventilation

unit and ducts



20



50



70



Ducts:

 

 

 



Constant air volume



100



200



300



Variable air volume



200



300



400



Terminal device



20



30



50



(5) In performing the

calculation of a variable air volume system in accordance with the simplified

method, the pressure drop value of the ductwork is assumed to remain constant. The

pressure drop of the variable air volume system Δpv (Pa)

is calculated by means of the following formula:

Δpv = Δpt

+ Δpmxp,



where Δptis the pressure drop of the ductwork and the terminal device in Pa;
Δpmis the pressure drop of the ventilation unit in Pa;
xp is the pressure drop factor of the variable air volume

system, xp = 0,65.





§ 21. Auxiliary

devices of ventilation systems



(1) The

wattage Phr (kW) of the pump of a run-around coil heat

exchanger is calculated by means of the following formula:

where  VSK is the flow rate of the heat exchange fluid in m3/s;
ηpis the efficiency factor of the pump;
Δpris the pressure drop of the liquid side of the heat

exchanger in kPa (kilopascal);
Δppis the pressure drop in kPa of the pipework which contains

the heat exchange fluid ;
Δpv is the pressure drop of the regulator valve in kPa.



(2) The

estimated pressure drop value of 0.2 kPa/m may be used as the pressure drop

value of the pipework  run-around coil. The pressure drop values of the fluid

side of the heat recovery unit fall into the following ranges: 60 kPa (low),

100 kPa (normal) and 150 kPa (high). The pressure drop of the three-way valve (the

regulator valve of the heat exchange fluid) may be deemed to equal 40% of the

pressure drop for the entire system (including the pressure drop of the valve).

Where the system is controlled by adjusting the rotation speed of the pump, the

pressure drop of the regulator valve Δpp = 0 kPa.



(3) The

efficiency factor ηp of the pump may be deemed to equal

0.3.



§ 22. Electrical

energy use of ventilation units in small residential buildings and apartments



(1) The

electrical energy use Ev (kWh/y) of small ventilation units

whose air flow rate is lower than 0,25 m3/s is calculated by means

of the following formula:



Ev

= Pvs tvsn xp,



where Pvs

is the wattage of the ventilation unit in kW at design air flow rate;
tvsn is the annual number of operating hours of the

ventilation unit at design air flow rate (in general, the value of tvsn

is 8760 h, except in the case of systems controlled on a demand basis);
xp is the pressure drop factor of the ducts.



(2) The

wattage Pvs of the ventilation unit is deemed to equal the

value which is provided by the manufacturer of the ventilation unit for the design

air flow rate and which has been measured in accordance with the standard EVS-EN

13141-7.



(3) The

pressure drop factor xp of the ducts is determined on the

basis of the data set out in Table 13 of this regulation.



Table 13. Pressure drop factor xp of the ducts

Pressure drop factor



Pressure drop level in ductwork



Pressure drop in supply

ductwork



Low
35 Pa





Normal
50 Pa





High
100 Pa





xp



0.8



1.0



1.2



Division 3

Cooling systems



§ 23. Calculation

of the energy use of cooling systems



(1) The

energy use of a cooling system is composed of the energy use for the production

of cooling energy and the electrical energy use by the auxiliary devices

required for the distribution and emission  of cooling energy.



(2) The

energy use for cooling during the cooling period Qj (kWh/y) including

condensation losses and the thermal losses related to the distribution and emission

of cooling energy is calculated on the basis of the energy need for cooling as

follows:
where Qjeis

the energy need of the cooling coils  of ventilation units in kWh/y;
Qrs is the energy need of room conditioning  units in kWh/y;
βje is the factor describing heat losses related to the

cooling coils  of ventilation units;
βrs is the factor describing heat losses related to the

distribution of cooling energy between room  units and the emission  of cooling

energy.



§ 24. Calculation

concerning single-stage cooling systems



(1) For

compressor-driven cooling systems, the electrical energy delivered to the

cooling system during the cooling period EQ (in kWh/y) is

calculated by means of the following formula:

where Qj is the energy use for cooling in kWh/y,

including condensation and heat loss;

Ea is the electricity use of auxiliary devices in kWh/y;

ε is the energy efficiency ratio  of the cooling energy

production process during the cooling period.



(2) The thermal energy Qjt

(in kWh/y) delivered to absorption cooling systems is calculated by means of

the following formula, to which the electricity use Ea of

auxiliary devices is added:

where ε is the energy

efficiency ratio  of the cooling energy production process during the cooling

period;

Qj is the energy use for cooling in kWh/y, including

condensation and heat loss in kWh/y.



(3) The energy efficiency

ratio ε of the cooling period is calculated on the basis of the full load

and part load value given by the manufacturer of the unit respectively in accordance

with the standards EVS-EN 14511-2 and EVS-EN 14825 or on the basis of the ESEER

value given by the manufacturer; or taken to equal the value given in Table 14.

When calculating the cooling factor on the basis of the ESEER value, the fact

that that value is based on the capacity of the compressor module and does not

include the electricity use of the condenserfans and pumps must taken into account and the

corresponding amount deducted from the ESEER value.



Table 14. Energy efficiency

ratios describing the cooling energy production process during the cooling

period

Manner of production of

cooling energy



ε



Compressor-driven

cooler



3.5



Natural cooling, liquid

cooler

Natural cooling, ground

loop (horizontal)

Absorption cooling



5

30

0.7



(4) System

losses are determined by means of a simulation calculation or by using the

values given in Table 15. Where the calculation concerning the energy need of

the cooling coil already accounts for condensation, the factor βje that states

the relevant value without condensation losses must be used. If condensation

has not been accounted for, the factor βjek that includes

condensation losses must be used.



Table 15. Factors describing

the condensation losses of the cooling process and the heat loss of the

distribution and emission  of cooling energy

Cooling water supply

temperature



βje



βjek



βrs



7 °C



0.3



0.6



0.2



10 °C



0.2



0.5



0.15



15 °C



0.1



0.2



0.1



18 °C



0.0



0.0



0.0



(5) The βje and ja βrs factors

of split and VRV type units (local units with separate cooler and condenser

elements) are deemed to equal zero because their heat losses have been

accounted for as part of the energy efficiency ratio.



(6) The SEER value stated in

the energy performance certificate of air conditioning units and air-to-air

heat pumps (split and VRV type) of up to 12 kW capacity may be used as the energy

efficiency ratio with respect to the cooling period. The condensation losses of

such units may be accounted for by using the values corresponding to the supply

temperature +7 °C of cooling water as stated in Table 15.



§ 25. Calculation

of the electrical energy use of cooling systems that utilise free cooling



Where the

cooling energy that is consumed in a building is derived from free cooling and harvested

by means of a compressor-driven cooling unit, the delivered energy of the

cooling system during the cooling period is calculated by means of the

following formula:

where α1

is an estimated proportion of the yearly cooling energy produced by means of

production process 1;
α2 is an estimated proportion of the yearly cooling

energy produced by means of production process 2 (α1 + α2

= 1.0);
ε1is the energy efficiency ratio  of production process

1 for the cooling period;
ε2 the energy efficiency ration  of production process 2

for the cooling period;
Qj is the cooling energy use during the cooling period in

kWh/y including any condensation losses and heat losses;
Ea is the electrical energy use of auxiliary devices in kWh/y.



§ 26. Calculation

of electrical energy use by auxiliary devices of cooling systems



(1) Where

it is not possible ot calculate the electrical energy use Ea

(in kWh/y) of auxiliary devices which consume electrical energy (such as the

pumps in the cooling system, the fans of fancoils  as well as other auxiliary

devices) with a higher accuracy, that use is calculated by means of the

following formula:

where βa

is the electricity use factor of the auxiliary devices of the system during the

cooling period;

Qj is the energy need in kWh/y for cooling the space served

by the system during the cooling period.

(2) The

electricity use factor may be deemed to equal the following values:

1) for hydronic systems with chilled  beams, 0.05

2) for hydronic systems with fancoils, 0.08

3) for VAV (variable air volume) ventilation systems, 0.05

4) for split and VRV (variable refrigerant volume) units, 0 (auxiliary devices

are accounted for in the cooling factor).

Division 4

Local renewable energy systems



§ 27. Use of solar energy

for the production of thermal energy



(1) The thermal energy produced

by a solar collector and the electrical energy used by the circulation pump is

calculated either by means of the relevant software or the formula set out

under subsection 2 below. The software must allow the use of climatic

parameters of the test reference year of the Estonian energy calculations,

permit the accounting of the solar radiation flow which reaches the collector

surface as a function of the collector’s orientation, tilt and shading, make

provision for the heat loss of the collector and the system, take into account the

particular manner of charging the accumulation tank and the use of thermal

energy in the building, and include in the calculation the technical parameters

provided by the manufacturer.



(2) Where more precise data

are not available, the thermal energy of the hot household water provided by

the collector may be calculated by means of the following formula:

where Qkol is

the yearly thermal energy in kWh/y of the hot household water provided by the

solar collector;
210 is the thermal energy in kWh/(m2y) produced by the

collector for the active surface of the collector;
Akolis the active surface of the collector (in m2)

which is not overshadowed;
kik is the factor describing the orientation of the collector

with respect to the cardinal points (for kik values, see

Table 16);
knurk is the factor describing the collector’s tilt

with respect to the horizon (for knurk values, see Table 17).



Table 16. Collector or panel

orientation factor, kik

Orientation



kik, -



South-east/South/South-west



1.0



East/West



0.8



North-west/North/North-east



0.6



Table 17. Collector or panel

tilt factor, knurk

Tilt angle



knurk, -



o



1



30-70o



1.2



>70 o



1



(3) When the formula set out

under subsection 2 is used to perform the relevant calculation, the maximum

thermal energy of the hot household water provided by the solar collector

equals 50 % of the yearly energy use for the production of hot household water.

Any quantity by that threshold is exceeded is not taken into account in the

energy calculation.



(4) Where more precise data

are not available, the electricity use of the circulation pump of the solar

collector may be calculated by means of the following formula:

where Ekol.pump  is

the yearly electricity use in kWh/y of the circulation pump of the solar

collector;
Akolis the active surface of the collector (in m2)

that is not overshadowed;
tkol.pump is the yearly number of operating hours (h) of the circulation

pump of the collector.

Where more precise data are

not available, the number of operating hours of the circulation pump tkol.pump

may be deemed to equal 2000 h/y.



§ 28. Use of solar energy

for the production of electrical energy



(1) The electrical energy

produced by means of solar panels in a year is calculated by means of the

following formula:

where Epan is

the electrical energy (in kWh/y) produced by the solar panels during the year;
Qpäikeis the yearly solar energy (in kWh/y) which reaches

the surface of the panels that is not overshadowed;
Pmaxis the maximum capacity in kW of the solar panels at

standard operating conditions (Iref= 1 kW/m2, temperature

25 oC);
kkas is the factor describing the use conditions of the solar

panels;
Iref is the standard value of solar irradiance, 1 kW/m2.



(2) The yearly solar energy

that reaches the surface of solar panels is calculated by means of the

following formula:

where 960 is the yearly

solar radiation in kWh/(m2y) that reaches a horizontal surface;
kik is the factor describing the orientation of solar panel

with respect to the cardinal points (for kik values, see

Table 16);
knurk is the factor describing the collector’s tilt

with respect to the horizon (for knurk values, see Table 17).



(3) The maximum capacity of

the solar panel Pmax at standard operating conditions depends

on the type of the panel and is calculated on the basis of the

manufacturer’s data. The use conditions factor kkas accounts

for the environmental parameters that prevail on the site (temperature, installation

parameters) and for losses related to converting the harvested energy to

alternating current. Where specific data are not available, the values stated

in Table 18 may be used.



Table 18. Solar panel

efficiency factor, kkas

Installation type



kkas, -



No air-cooling



0.7



Moderately air-cooled



0.75



Intensely air-cooled



0.8



§ 29. Electricity generated from wind



(1) The calculation of the electricity generated from

wind must be based on wind parameters at the location of the wind turbine and

take into account the efficiency of the turbine and the size of its blades. The

data of the Estonian test reference year for energy calculations cannot be used

for calculating the electricity generated from wind.



(2) The annual electricity generated by a wind turbine is

calculated by means of the following formula:


where Etuul

is the annual electricity in kWh/y generated by the wind turbine;
Atiivik is the area in m2 formed by the turbine

blades against the air flow;
vi is the wind speed in m/s at which the wind turbine

generates electricity;
vmin is the lowest wind speed in m/s at which the wind

turbine generates electricity;
vmax is the highest wind speed in m/s at which the wind

turbine generates electricity;
ρ is the density of air, 1.2 kg/m3;
ηgen,iis

the aggregate efficiency of the wind turbine at specific wind speed vi

that is obtained from the data provided by the manufacturer;

ti is the number of the operating hours (h) of the turbine corresponding to the

wind speedvi.



(3) The annual

electricity generated by a wind turbine may also be calculated by means of the

following simplified formula:

where Etuul

is the annual electricity in kWh/y generated by the wind turbine;
Atiivik is the area in m2 formed by the turbine

blades against the air flow;
vk is the average wind speed in m/s;
ρ is the density of air, 1.2 kg/m3;
ηk.gen is the annual aggregate efficiency of the wind

turbine, which is obtained from the data provided by the manufacturer;
B is the factor describing the distribution of wind speed during the

operation of the wind turbine throughout the year (1.5 where more precise data are

unavailable);
t is the number of operating hours of the turbine per year.





Chapter 6

REQUIREMENTS FOR THE PRESENTATION OF THE RESULTS OF

ENERGY CALCULATION



§ 30. Requirements for

the presentation of calculation results



(1) The input parameters used in the energy

calculation are presented in the format provided in Annex 1 of this regulation.

In the case of proving the compliance of a small residential building with the

limit value of the energy performance indicator in accordance with the

simplified method, the input parameters and calculation results are presented

in the format provided in Annex 2 of this regulation.



(2) The results of the energy calculation are

presented in the format provided in Annex 3 of this regulation. A summary of delivered and exported energy must

be presented with respect to all energy carriers used in the provision of the building’s

energy supply (electricity, district heating and/or various fuels) in

accordance with the results of the calculations concerning its utility systems.



(3) The results of the calculations

concerning the utility systems are entered in the table of total energy use

provided in Annex 3 of this regulation. The energy use of the ventilation

system, lighting, appliances and, in general, also of the cooling system consists

solely of electrical energy, and is entered, together with the electrical

energy use of the heating system, into the corresponding fields in the

electricity column. The thermal energy use of the heating system is presented in

accordance with the energy supply solution of the heating system in the thermal

or electrical energy column, by way of allocations to space heating, the heating

of ventilation air and the heating of household water. Local renewable energy, the

electricity fed into the power network and the thermal energy fed into the

supply or return pipeline of the district heating network are presented in the

table of local renewable energy and exported energy.



(4) The

quantities of obtained fuels are calculated as the product of delivered thermal

energy and the lower calorific value of the fuel. The lower calorific values of

consumable substances are deemed to equal the data provided by the manufacturer

or the values provided in Annex 4 of this regulation.



(5) The energy carrier conversion factors

are set out in the regulation entitled Minimum Requirements for

Energy Performance established in accordance with

subsection 72 of section 3 of the Building Act. Weighted energy use

is calculated as the product of the difference between delivered energy and

exported energy and of the energy carrier conversion factor.



(6) The energy performance indicator ETA

is calculated by dividing the difference between the total delivered energy

use and the total exported energy by the number of square metres of heated

area:

where ETA

is the energy performance indicator expressed in kWh/(m2 y);
Etar,i is the energy delivered (in kWh/y) by means of the

energy carrier i;
Eeks,i is the energy exported (in kWh/y) by means of the

energy carrier i;
fi is the weighting factor of the energy carrier i; -
Aneto is the heated area in m2.



When presenting

the results of the calculation of delivered and exported energy, the following

formula is considered to hold with respect to each energy carrier:

where Esum,i

is the building’s total energy use in kWh/y in relation to the energy

carrier i;
Elok,i is the local renewable energy in kWh/y related to the

energy carrier i.



(7) The results of the verification of

summertime indoor temperature with regard to all calculated rooms which

represent room types are presented in the format provided in Annex 5 of this

regulation. With respect to residential buildings, the presentation of the

duration curve is not compulsory. Where the verification calculation of

summertime indoor temperature is not performed with respect to a small

residential building, the data proving the exemption of the rooms

representative of room types from the temperature verification requirement are

presented in the format provided in Annex 6 of this regulation.



(8)

When presenting the results, the fields in coloured rows and the columns in

Annexes 1–3 and 5–6 must be completed.



Chapter 7

IMPLEMENTING PROVISIONS



§ 31. Implementation

of this regulation



(1) Where the application

for a building permit is submitted before 9 January 2013, but the building

permit is issued after that date, the requirements established in this

regulation do not apply.

(2) This regulation enters into force on 9 January 2013.











1 Directive 2002/91/EC of the European

Parliament and of the Council on the energy performance of buildings (OJ L 1,

4.01.2003, pp. 65–71), amended by Directive 2010/31/EU of the European Parliament

and of the Council on the energy performance of buildings (OJ L 153,

18.06.2010, pp. 13–35)

Juhan Parts
Minister
Marika Priske
Secretary-General

Annex 1 Presentation of input parameters of the energy calculation
Annex 2 Presentation of input parameters of the energy calculation concerning the proving of compliance, in the case of small residential buildings and in accordance with the simplified method, with the limit value of the energy performance indicator
Annex 3 Presentation of the results of the energy calculation
Annex 4 Lower calorific values of the consumable substances of fuels
Annex 5 Presentation of the results of the verification of summertime indoor temperature
Annex 6 Data concerning rooms representative of room types in small residential buildings
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