Compilation of Information Papers - REHVA...Compilation of Information Papers introducing the CEN standards concerning Overall Energy Performance of Buildings Boundary conditions EP

Energy Performance of Buildings

www.iee-cense.eu

BOOKLET 1

Compilation of Information Papers introducing the CEN standards concerning Overall Energy Performance of Buildings

Boundary conditions

EP

Building energy needsand system energy losses

Assessment of overall Energy Performance (EP)

Comm

onterm

s, definitionsand sym

bols

Component input data

EPexpressions

EP aggregation

Boundaries, classification

Collect all energy elements

IEE-CENSE Leading the CEN Standards on Energy performance of buildings to practice

Towards effective support of the EPBD implementation and acceleration in the EU Member States

BOOKLET 1

Compilation of Information Papers introducing the CEN standards concerning Overall Energy Performance of Buildings

Content General introduction 3 Cluster 1: Common terms and symbols for set of European standards

on energy performance of buildings 5 - Introduction - Information Paper

IP 154 Information paper on the common definitions and common symbols for EPBD related CEN standards

Given in CEN Technical report CEN/TR 15615 ("Umbrella Document') Cluster 2: Methods for expressing energy performance and for energy

certification of buildings 15 - Introduction - Information Paper

IP 155 Energy performance certificates EN 15217 "Energy performance of buildings – Methods for expressing energy

performance and for the energy certification of buildings" Cluster 3: Overall energy use and definition of energy ratings 23

- Introduction - Information Papers

IP 88 Information paper on Energy performance of buildings – Overall energy use and definition of energy ratings – Calculated energy rating

EN 15603 (Overall energy use) IP 87 How to integrate the CEN-EPBD standards in national building

regulations? The use of EN 15603 to adopt the same structure as starting point for coordination of

Member States regulations IP 89 Measured or operational energy performance of buildings

Procedures for defining measured energy use and operational ratings and for presenting measured energy performance results on building energy certificates.

Disclaimer: CENSE has received funding from the Community’s Intelligent Energy

Europe programme under the contract EIE/07/069/SI2.466698. The content of this

document reflects the author’s view. The author and the European Commission are

not liable for any use that may be made of the information contained therein.

© European Communities, 2010

Reproduction is authorised provided the source is acknowledged

Booklet 1

Booklet Overall Energy Performance of Buildings Page 3/44

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General introduction

The aim of the CENSE project is to support the EU Member States and other target groups in gaining awareness and achieving effective use of the European (CEN) standards that are related to the EPBD.

These standards were successively published in the years 2007-2008 and are currently either already being implemented or will soon be implemented in many EU Member States.

The European Commission, DG TREN and DG Enterprise, gave Mandate 343 to CEN. It ordered CEN to develop a methodology for calculating the integrated energy performance of buildings in accordance with the terms set forth in Directive 2002/91/EC (Energy Performance of Buildings Directive-EPBD).

Access to this methodology in the form of European Standards makes it possible to coordinate the various measures for improving the energy efficiency in buildings that are used in the Member States. It will increase the accessibility, transparency and objectivity of energy performance assessment in the Member States (as mentioned in recital (10) of the EPBD).

The role of the EPBD-CEN standards is to provide a common European concept and common methods for preparing energy performance certification and energy inspections of buildings. However, the implementation of these CEN standards in the EU Member States is far from trivial: the standards cover a wide variety of levels and a wide range of interlaced topics from different areas of expertise. They comprise different levels of complexity and allow differentiation and national choices at various levels for different applications.

One of the main activities in the CENSE project is “to communicate the role, status and content of these standards as widely as possible and to provide guidance on their implementation”. To fulfil this task many so called Information Papers have been published with background and practical information related to the CEN standards developed in the framework of the EPBD. The Information Papers of each work field in the energy building sector are compiled in a Booklet as present. This Booklet is part of a series consisting of the following volumes:

Booklet 1: Overall Energy Performance of Buildings

Booklet 2: Building Energy Performance

Booklet 3: Heating Systems and Domestic Hot Water

Booklet 4: Ventilation and Cooling Systems

Booklet 5: Inspection of Systems for Heating, Air Conditioning and Ventilation

In each booklet the Information Papers are clustered to the specific appliances, systems, calculation methods, etc. Additional to each Information Paper a PowerPoint presentation is at disposal for dissemination and training purposes. All these documents and more information, like a database with frequently asked questions, are separately available on the CENSE website: http://www.iee-cense.eu/

A second major activity in the CENSE project is "to collect comments and good practice examples from EU Member States aiming to remove obstacles and to collect and secure results from relevant SAVE and FP6 projects". This feed back aimed to produce recommendations to CEN for a "second generation" of CEN standards on the energy performance of buildings. Several reports from questionnaires and workshops, draft recommendations, etc. were gradually made available on the CENSE website for comment: http://www.iee-cense.eu/.

All final products from the project will be available at the website before the end of May 2010.

http://www.iee-cense.eu/


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The consortium of the project consists of thirteen partners (from nine different countries) who are all experts and active in CEN-EPBD. They combine this expertise with knowledge and experience of implementation at the national level.

TNO (coordinator) The Netherlands www.tno.nl

Berrie van Kampen*, Dick van Dijk*, Hans van Wolferen, Theo Thijssen, Marleen Spiekman

CSTB France www.cstb.fr

Johann Zirngibl, Hicham Lahmidi, Claude François, Jean-Robert Millet

ISSO The Netherlands www.isso.nl Jaap Hogeling, Kees Arkesteijn

Fraunhofer - IBP Germany www.ibp.fraunhofer.deHans Erhorn, Anna Staudt, Jan de Boer

DTU Denmark www.ie.dtu.dkBjarne Olesen, Peter Strøm-Tejsen

Camco United Kingdom www.camcoglobal.com Robert Cohen

FAMBSI Finland www.fambsi.fi Jorma Railio

EDC Italy www.edilclima.it Laurent Socal

HTA Luzern Switzerland www.hslu.ch Gerhard Zweifel

BRE United Kingdom www.bre.co.uk Roger Hitchin, Brian Anderson

Viessmann Germany www.viessmann.de Jürgen Schilling

Roulet Switzerland www.epfl.ch Claude-Alain Roulet

JRC (IES) Eur.Commission ies.jrc.ec.europa.eu Hans Bloem *: Project coordination Collaboration has been established with the following European umbrella (mainly branch) organizations, such as CEN BT/TC 371, EuroAce, EURIMA, EHI, REHVA, EUROVENT, ESTIF, Euro Heat & Power and ECOS (see website for details).

http://www.tno.nl/

http://www.cstb.fr/

http://www.isso.nl/

http://www.ibp.fraunhofer.de/

http://www.ie.dtu.dk/

http://www.fambsi.fi/

http://www.edilclima.it/

http://www.hslu.ch/

http://www.bre.co.uk/

http://www.viessmann.de/

http://www.epfl.ch/

http://ies.jrc.ec.europa.eu/

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Cluster Common terms and symbols Introduction The CEN Technical Report CEN/TR 15615 describes the European standards (ENs) that are intended to support the EPBD by providing the calculation methods and associated material to obtain the overall energy performance of a building.

In Annex A of this Technical Report the standards concerned are arranged in a hierarchical fashion. Section 1 of Annex A lists standards concerned with overall energy performance in support of Articles 4 to 7 of the Directive. Sections 2 to 5 list the standards relating to specific aspects or modules of building energy performance which contribute to the overall calculation. The content of the individual standards is summarised in Annex B. Annex C provides a list of definitions, and Annex D a list of principal symbols, that are used consistently in the standards. It is intended that these annexes will form the basis of a future trilingual standard covering common definitions and symbols for energy calculations.

Information paper P154 introduces common terms and symbols for set of European standards on energy performance of buildings.

Information paper IP 154: Information paper on the common definitions and common symbols for

EPBD related CEN standards Given in CEN Technical report CEN/TR 15615 ("Umbrella Document') Presentations Besides Information Papers, corresponding presentations have been prepared to support communication about EN EPBD standards as well as lectures. Presentations often include notes to explain the slides and to support lecture preparation. Presentations can also be downloaded freely from http://www.iee-cense.eu/


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A few examples of the (in total more than 100) common definitions (see chapter 3 of this paper):

C.1.4 technical building system technical equipment for heating, cooling, ventilation, domestic hot water, lighting and electricity production

NOTE 1 A technical building system can refer to one or to several building services (e.g. heating system, heating and DHW system).

NOTE 2 A technical building system is composed of different sub-systems.

NOTE 3 Electricity production can include cogeneration and photovoltaic systems.

C.1.22 conditioned space heated and/or cooled space

NOTE The heated and/or cooled spaces are used to define the thermal envelope.

C.2.6 heat recovery heat generated by a technical building system or linked to a building use (e.g. domestic hot water) which is utilised directly in a related system to lower the heat input and which would otherwise be wasted (e.g. preheating of the combustion air by a flue gas heat exchanger)

This was also reflected in the terminology, which was not necessarily the same in all CEN Technical Committees and which could easily lead to a Babel-like confusion. Figure 1 shows, as example, a number of terms that were found to be used for energy need and energy use, without a clear picture whether these terms had the same or a different meaning.

Fig. 1. Tower of Babel or towards common definitions?!

Definitions

Consequently, one of the important actions was the preparation of a set of common definitions on the main concepts and physical quantities. Due to the limited time available to develop the standards, the preparation of common definitions was carried out in parallel with the drafting of the standards. The coordinating task force in CEN, CEN/BT TF 173 (currently called CEN/BT TC 371) was responsible for this action. The action focussed on harmonization of terms used in the top level standards.

Symbols

The CEN standards to support the EPBD introduce a large number of quantities and their associated symbols. To facilitate the use of the standards, a common set of symbols and subscripts have been defined.

CENSE > P154_EN_CENSE_CEN_TR_15615_Defs_Symbols 2

3 > Common definitions

A few more examples of the (in total more than 100) common definitions (see chapter 3 of this paper):

C.5.1, energy performance of a building

calculated or measured amount of weighted net delivered energy actually used or estimated to meet different needs associated with a standardised use of a building, which may include, inter alia, energy used for heating, cooling, ventilation, domestic hot water and lighting

C.5.2, energy performance requirement

minimum level of energy performance that is to be achieved to obtain a right or an advantage: e.g. right to build, lower interest rate, quality label

C.5.3, energy rating

evaluation of the energy performance of a building based on the weighted sum of the calculated or measured use of energy carriers

In total, more than 100 terms have been selected that are common to the top level CEN standards to support the EPBD. The list, illustrated in figure 2, is adopted as annex C of CEN/TR 15615, the "Umbrella Document". A few examples are given in the left insert.

Most of these definitions can also be found in the top level CEN standard EN 15603. Information Papers P087 and P088 provide more information on that standard.

• Energy ratings and certification– energy performance of a building– energy rating– calculated energy rating– standard energy rating– design energy rating– tailored energy rating– standard use data set– measured energy rating– confidence interval– statistical tolerance interval– energy certification– energy indicator– standard calculated energy

indicator

• Buildings:– building– new building– existing building– technical building system– technical building sub-

system– internal dimension– overall internal dimension– external dimension– thermal envelope area– heated space– cooled space– conditioned space– unconditioned space– conditioned area– conditioned zone– occupied zone

• Energy calculation– space heating– space cooling– building calculation mo– validated building data– calculation step– calculation period– heating or cooling sea– external temperature– internal temperature– set-point temperature

conditioned zone– equivalent internal

temperature:– set-back temperature

heat transfer coefficien

• Technical building systems– auxiliary energy– cogeneration– air conditioning system– room conditioning system– demand controlled

ventilation– dehumidification– humidification– ventilation– ventilation heat recovery

• Energy– energy source– energy carrier– energyware– system boundary– delivered energy– exported energy– net delivered energy

Fig. 2. Illustration of the kind of terms included in the common definitions

4 > Common symbols and subscripts

Introduction

In addition to the common definitions, a list of common symbols and sub-scripts was prepared for the main physical quantities that are commonly used in the top level standards.

The selected symbols only concern data passed from one standard to another. Additional symbols and units may be used locally within each standard, but it is strongly recommended to use the common symbols, subscripts and order.

The list, introduced below, is adopted as annex D of CEN/TR 15615, the "Umbrella Document". A few examples are given in the left insert.

The following table shows some examples of common symbols from CEN/TR 15615.


Table 1 — Common symbols, some examples

Sym-bol

Quantity Unit Sym-bol

Quantity Unit

A area m² Q quantity of heat J a

C heat capacity J/K a q volumetric airflow rate m3/s

c specific heat capacity J/(kg·K) a q heat flow density W/m²

E energy in general; including primary energy, energy carriers (except heat, auxiliary electricity and work)

kg, m3, J a

b t time, period of time s a

EP energy performance indicator

J/(m2.a) a, kg/(m2.a), €/(m2.a) c

W (electrical) auxiliary energy

J a

I solar irradiance W/m2 η efficiency factor -

m mass (e.g. quantity of CO2 emissions)

kg θ Celsius temperature °C

P power in general including electrical power

W Φ heat flow rate, thermal power

W

a Hours (h) may be used as the unit of time instead of seconds for all quantities involving time (i.e. for time periods as well as for air change rates), but in that case the unit of energy is Wh instead of J. b The unit depends on the type of energy carrier and the way its amount is expressed. c The unit depends on the indicator chosen, see EN 15217 clause 5.

Subscripts

The main subscripts are provided in four successive levels.

It goes from the general to the detailed:

› the first level is related to the use, › the second is related to the main topics influencing the energy

performance (energy carrier, heat transfer building envelope, technical building system),

› the third is related to energy balance items or it qualifies the higher level,

At each level there may be different sets of subscripts, for different contexts. For example: in a certain context a distinction is required between type of energy use (heating versus cooling versus ventilation, etc.), while in another context a distinction is needed between the energy carrier (gas versus oil versus electricity versus…). But a distinction is never required between energy use for heating versus gas.

The levels are hierarchic, to harmonise the order of the subscripts used in different standards.

NOTE For example: recoverable ventilation system losses: good: QV,sys,ls,rcb wrong: Qls,V,rcb..

Because of its importance in helping to make the CEN standards accessible, transparent and consistent, the full table of these four levels from CEN/TR 15615 is given in the annex to this paper.


Use of the common symbols and subscripts in other languages:

In CEN/TR 15615 the terms for the common symbols and subscripts are also translated into French and German.

It is strongly suggested to use the same symbols and subscripts in translated national standards and/or related (national) documents, with the English expression given as additional information, to explain the origin of the abbreviation.

Table 2. A few examples of the common symbols used in another language (from Dutch OntwNEN 7120): Symbool Grootheid Eenheid Engelse oorsprong

A Oppervlakte m2 Area

H warmteoverdrachtscoëfficiënt W/K Heat transfer coefficient

R warmteweerstand M2K/W Thermal resistance

Table 3. A few examples of the common subscripts used in another language (from Dutch OntwNEN 7120 and from Italian UNI/TS 11300-1) Index Betekenis Engelse oorsprong

del aangeleverd delivered

C Koeling (energiegebruik voor ~)

Cooling (energy use for ~)

gen Opwekking Generation

Ventilation

Heating

Cooling

Lighting

Hot w

ater

Building

Solar

thermal

PV , local

Heat (*)

Electricity

“Fuel”*)

DeliveredExported

Electricity

Heat

*): “Fuel”: gas, oil, coal, wood, district heating, ..

Numerical indicator

Ventilation

Heating

Cooling

Lighting

Hot w

ater

Building

Solar

thermal

PV , local

Heat (*)

Electricity

“Fuel”*)

DeliveredExported

Electricity

Heat

*): “Fuel”: gas, oil, coal, wood, district heating, ..

Numerical indicator

Fig. 3: Diagram illustrating the energy delivered to and exported from a building site

Pedici Pedici

g terreno set regolazione

gl vetro sh ombreggiatura, schermatura

gn aporti termici shut Chiusura oscurante

5 > Building boundaries

One of the crucial elements in the definitions is the boundary of the building, including its technical building systems. Although the detailed procedures to define this boundary are set at national level, CEN provides common rules. Within the boundary a distinction is made between the building needs and the thermal losses of the technical building systems. The recoverable part of these losses may lead to an interaction with the building needs. Energy is delivered from outside the boundary by energy carriers, such as gas, electricity or heat. Additionally, renewable energy can be produced within its boundary. Optionally, energy can also be exported to outside, in the form of electricity and/or heat. More details can be found in the CENSE Information Paper P87 ("How to integrate the CEN-EPBD standards in national building regulations? The use of EN 15603 to adopt the same structure as starting point for coordination of Member States regulations").


6 > Example

The following example shows a technical building system where the symbols and subscripts are applied and where the building boundary is clearly indicated.

The example is only to illustrate the uses of the symbols, the delivered and exported energy carriers and the rating (energy use). Not all losses, auxiliaries, etc are indicated.

› Gen1: Solar collector producing only DHW

› Gen2: Photovoltaic panel exporting partly the electricity produced

› Gen3: Gas driven cogeneration unit for DHW production and exporting partly the electricity produced

› Gen4: Oil fired boiler for heating and DHW

› Gen5: Oil fired boiler for heating and DHW

WHW,gen,(in),4

Gen1 solar collector

QW,dis,ls,rcb

WW,dis,(aux)

QH,dis,ls,rcb

QH,dis,in

QW,dis,in

QH,nd

QW,nd

Epv,exp,2

I I

EHW,gen,(in),5

EHW,gen,(in),4

Eel,del

Eel,exp,3

E[a]W,gas,del EW,gas,del,Ptot EPtot E[a] ,W,gen,( in),3

Eel,prd,3

QW,sol,del,1

QW,gen,out,1

QW,gen,out,3

E(Tot)pv,del,2

EL

Gen2PV panel

QHW,gen,out4

QHW,gen,out,5

EHW,oil,del EHW,oil,del,Ptot

Eel,del,Ptot

Epv,exp,Ptot

Eel,exp,Ptot,3

QW,sol,del,Ptot

Epv,del,Ptot

Gen3gas CHP

Gen4 oil boiler

Gen5 oil boiler

System boundary

weighted energy carrier

unweighted energy carrier

Rating (energy use)

energy needs

QH,dis,ls WHW,gen,(in),5

[a] all inputs are counted for the thermal production ( ) optional subscript

W(aux)

Energy crossing the building boundary:

Outgoing: Exported energy (green)

Incoming: Delivered energy (yellow)

Fig. 4. Illustration of the application of the common symbols on a technical building system


7 > FAQ

Are the common definitions given in CEN/TR 15615 mandatory?

CEN/TR 15615 is not a standard, but a technical report and therefore the definitions (annex C) are not mandatory. However, most of the definitions are adopted also in the European standard EN 15603, which is one of the key standards in the set of standards to support the EPBD. It is intended that the annexes C and D of CEN/TR 15615 will form the basis of a future trilingual standard covering common definitions and symbols for energy calculations. Most Member States are planning to adopt the CEN standards in one way or another within a few years.

CENSE partners: TNO (NL; coordinator), CSTB (FR), ISSO (NL), Fraunhofer-IBP (DE), DTU (DK), ESD (GB), FAMBSI (FI), EDC (IT) Associated partners: HTA Luzern (CH), BRE (GB), Viessmann (DE), Roulet (CH), JRC IES (EC) Link: www.iee-cense.eu Original text language: English

cense

Are the common symbols given in CEN/TR 15615 mandatory?

CEN/TR 15615 is not a standard, but a technical report and therefore the common symbols and subscripts (annex D) are not mandatory. It is however strongly recommended to use these common symbols and subscripts also in translated national standards and other related national documents. It is intended that the annexes C and D of CEN/TR 15615 will form the basis of a future trilingual standard covering common definitions and symbols for energy calculations. Most Member States are planning to adopt the CEN standards in one way or another within a few years.

Why are the symbols in some of the EN ISO standards related to the EPBD not always the same as in the CEN standards to support the EPBD?

For instance: in EN ISO 13789 the subscripts for transmission and ventilation are T and V in ISO and tr and ve in CEN.

There may be two reasons: 1) because the EN ISO standard was already published before the common symbols were agreed upon in CEN (which was in 2007); 2) because the ISO standard is closely linked to other ISO standards which use different symbols.

8 > References 1. CEN/TR 15615: Explanation of the general relationship between various

European Standards and the Energy Performance of Buildings Directive (EPBD) – Umbrella Document. European Committee for Standardization (CEN), Brussels (April 2008)

2. EN 15603: Energy performance of buildings – Overall energy use and definition of energy ratings. European Committee for Standardization (CEN), Brussels (Jan. 2008)


Disclaimer: CENSE has received funding from the Community’s Intelligent Energy Europe programme under the contract EIE/07/069/SI2.466698. The content of this document reflects the author’s view. The author and the European Commission are not liable for any use that may be made of the information contained therein. © European Communities, 2009 Reproduction is authorised provided the source is acknowledged

http://www.iee-cense.eu/Partners.aspx

ANNEX: Table with the main sets of subscripts, from CEN/TR 15615 *)

Level 1 Level 2 Level 3 Level 4

Type of energy use Building without technical systems Utilised or non-utilised

H heating nd need ut utilised

C cooling ht heat transfer nut non-utilised

W DHW tr transmission heat transfer

T thermal ve ventilation heat transfer

L lighting gn gains

V ventilation sol solar

A appliances int internal

XY combination of H, C, W sens sensible

Tot total lat latent

Technical building system Balance item Balance item

us use ls losses rbl recoverable

sys system aux auxiliary rvd recovered

em emission in input nrbl non-recoverable

dis distribution out output nrvd non-recovered

st storage

ctr control

gen generation

hum humidification a

dhum dehumidification a

Energy carrier Qualifier (where used) Qualifier (which type)

gas gas del delivered nren non-renewable

oil oil exp exported ren renewable

el electricity pr produced

wd wood ntdel net delivered

dh district heating

dc district cooling aggregated quantity

sf solid fuel P primary energy

lf liquid fuel Ptot total primary energy

bm biomass Pnren non renewable primary fraction

sol solar heat CO2 CO2 emission

pv solar electricity

a Only at 'needs' level; energy use for humidification is included in energy use for ventilation; energy use for dehumidification is included in energy use for cooling

*): More detailed subscripts and detailed rules on their use can be found in CEN/TR 15615, annex D.


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Cluster Methods for expressing energy performance

and for energy certification of buildings Introduction Energy performance certificates will have to be available when buildings are sold or rented and will be displayed in public buildings. It is expected that this will have a major impact by increasing the awareness of building owners and users of the energy performance of their buildings. In France for example, 2 million certificates will be issued every year. It will probably play a key role in activating the improvement of existing buildings, which is a major challenge in reducing building CO2 emissions. Information paper P155 explains how the CEN (EPBD)-standard: EN 15217 "Energy performance of buildings – Methods for expressing energy performance and for energy certification of buildings" complements the directive. Information paper IP 155: Energy performance certificates

EN 15217 "Energy performance of buildings – Methods for expressing energy performance and for the energy certification of buildings"

Presentations Besides Information Papers, corresponding presentations have been prepared to support communication about EN EPBD standards as well as lectures. Presentations often include notes to explain the slides and to support lecture preparation. Presentations can also be downloaded freely from http://www.iee-cense.eu/


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[European projects]

Energy performanceEN 15217 "Energy performance oexpressing energy performance acertification of buildings"

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This paper gives information about thcertificates according to the EPBD reqstandards for the EPBD.

Energy performance certificates will buildings are sold or rented and will bbuildings. It is expected that this willincreasing the awareness of building operformance of their buildings. In Fracertificates will be issued every year.in activating the improvement of exismajor challenge in reducing building

This information paper explains how t15217 "Energy performance of buildinenergy performance and for energy ccomplements the directive.

1 > The EPBD requirements(directiv

Energy performance certificate

Article 7 of the EPBD stipulates the infomust contain.

Art.7/§1 indicates the situation and theshall be available for a building or an made available "...when buildings are co

Art.7/§2 gives some information about tcertificate:

› "shall include reference values su› "shall be accompanied by recomm

improvements of the energy perf

Member States shall take measurea total usable floor area overauthorities and by institutions prnumber of persons and therefopersons, an energy certificate, noa prominent place where it is clea

The range of recommended and cwhen appropriate, other relevanclearly displayed.

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1 6 - 0 5 - 2 0 0 9
certificates f buildings – Methods for nd for the energy

e Energy performance uirements and the CEN

have to be available when e displayed in public have a major impact by wners and users of the energy nce for example, 2 million It will probably play a key role ting buildings, which is a CO2 emissions.

he CEN (EPBD)-standard: EN gs – Methods for expressing ertification of buildings"

e 2002/91/EC)

rmation that an energy certificate

point in time when a certificate apartment. The certificate shall

nstructed, sold or rented out …".

he content of the certificate. The


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ore information can be found athe CENSE project website: ww.iee-cense.eu

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ch as current legal standards…", endations for cost-effective ormance".

s to ensure that for buildings with 1000 m2, occupied by public oviding public services to a large re frequently visited by these

t older than 10 years, is placed in rly visible to the public.

urrent indoor temperatures and, t climatic factors, may also be


Improvement of the building?

The requirements of Article 7 are very general. More details are provided in other Articles of the EPBD.

Definitions

Article 2 defines the term "energy performance " in Article 7.

Art.2/§3 states that an energy certificate of a building is "…the energy performance of a building calculated according to a methodology based on the general framework set out in the Annex."

It should be noted that:

› the energy performance is calculated, (legally even a calculation based on energy bills can be considered as a calculation.)

› the energy performance is evaluated according to a methodology that is based on the general framework in the Annex of the directive.

How should the energy performance of a building be expressed?

Art.2/§2 states that "the energy performance of a building is the amount of energy actually consumed or estimated to meet the different needs associated with a standardised use of the building …. . This amount shall be reflected in one or more numeric indicators that have been calculated taking into account …"

Annex "General framework for the calculation of the energy performance of buildings (article 3)"

The annex defines the content of the certificate more rigorously.

Annex/§1 states that the methodology shall include at least the following aspects:

› the building shell thermal characteristics, position and orientation, passive solar systems and solar protection, etc.

› the technical building systems and uses heating installation, hot water supply, air-conditioning installation, ventilation, natural ventilation, built-in lighting.

Annex/§2 states that the positive influence of the following aspects shall be taken into account;

› Innovative systems active solar systems, other heating and electric systems that use renewable energy sources, electricity produced by CHP.

› Large scale systems (local community systems) (energy systems situated outside the building), district or block heating and cooling systems.

Taking into account systems situated outside the building emphasises the primary energy approach in the certificate.

CENSE > P155_EN_CENSE_EN_15217 2

Example of an Energy certificate according to EN 15217

Energy certificate based on measured energy use displayed in public buildings in Germany

2 > En 15217 "Energy performance of buildings – Methods for expressing energy performance and for the energy certifica-tion of buildings"

EN 15217 provides methods that are required to express the energy performance (EP) of buildings.

The certificate can be based on either the measured or the calculated rating. Both indicators have their pro’s and con’s.

A calculated rating highlights the intrinsic potential of the building while a measured rating makes it possible to take into account the impact of building management.

In the selection of relevant indicators, the following points should be taken into account:

› For new buildings, a measured energy indicator is not available, so a calculated rating based on design data is the only practical means of assigning an indicator.

› A measured energy indicator will no longer be valid after a change of building occupant or a change in the pattern of use of the building.

› In existing public buildings where there is no change in ownership, the measured energy indicator can be a measure of the quality of the facility management and can be used to motivate building operators and users.

› A standard calculated energy indicator requires the collection of data on the building (insulation, heating system, etc.), which will be useful for giving advice on the improvement of its energy performance.

› For managers of buildings, a measured energy indicator can often be easily obtained from the data that is already available in their information systems (energy bills, areas, etc.).

› Measured energy indicators and standard calculated energy indicators are not necessarily based on the same uses of energy.

In the following sections the chapters of the standard that are related to certificates will be discussed.

"Energy performance indicators"

Chapter 5 of EN 15217 states that "the energy performance of a building is represented by an overall indicator EP determined according to EN 15603". The overall indicator is related to the conditioned floor area AC in order to facilitate the comparison of the energy performance between buildings.

- Different indicators can be used on a certificate

The certificate shall contain an easy-to-understand global indicator of the energy consumption of the certified building. Different forms of energy can be delivered to a building: e.g. gas, electricity, wood… The indicator will be a weighted sum of these delivered energies. Depending of the weight chosen, the indicator can represent either:

› Primary energy › CO2 emissions › Total energy cost › A weighted sum of the net delivered energy weighted by any other

parameter defined by national energy policy.


Energy certificate based on calculated energy use for non-residential buildings in the Netherlands.

Energy certificate based on measured energy use displayed in public buildings in the UK

- Conditioned area AC

The type of dimensions used to calculate AC is not standardized yet because there are many different conventions in the member states. Therefore

› internal dimensions, › external dimensions, › overall internal dimensions

may still be used.

According to EN 15217 the type of dimensions shall be specified in the certification procedure.

The type of dimensions has a high impact on the indicator EP. For a single-family dwelling of 10 x 10 m, the indicator obtained using internal dimensions could be 20 % higher than the one obtained using the external dimension of the same house.

The type of dimensions used in the calculation has an impact not only on the indicator EP but also on the values calculated for the heat transfer, the hot water demand, lighting, etc. This should be remembered when choosing the type of dimensions and also when setting up the calculation methods to be used when including these building services.

It should be noted that heat losses are not directly proportional to the conditioned floor area, because buildings with different shapes may have different heat losses even if they have the same conditioned floor area . Using only the conditioned area introduces distortions in the comparison between buildings, because it is easier for a larger building to improve its performance.

"Reference values"

According to the requirements in the directive, EN 15217 specifies that "reference values shall be defined for classes of buildings having different functions (e.g. single family houses, apartment blocks, office buildings, educational buildings, hospitals, hotels and restaurants, sports facilities, wholesale and retail trade service buildings, other types)."

The function refers to the different building services that are required (heating, domestic hot water, air-conditioning), different specifications for the internal climate and different occupant densities and occupancy schedules (buildings used 5, 6 or 7 days a week).

The current legal status (e.g. required EP, minimum EP for new buildings) and the building stock must be used as references.

The reference values shall be documented, not on the individual certificate but in a report that can be easily consulted (e.g. one that is available on a website), taking into account the following aspects:

› type of reference value, › building function, › uses considered, › assumptions regarding internal and external climate, › assumptions regarding use patterns, › procedure to be used to select the correct reference value.



Procedure for building certification

In addition to the requirements of the directive, EN 15217 indicates that the energy certificate may contain energy classes.

The performance scale shall range from A (buildings of highest energy performance) to G (buildings of lowest energy performance). The current legal status shall be placed at the boundary between classes B and C, while the building stock reference shall be placed at the boundary between classes D and E.

Certificate shape

The format of the certificate is very important to enable an easy understanding by non specialists. The CEN standard offer three examples of certificate layout which can be used as a basis by Member States:

› the first example includes a calculated rating and energy classes, › the second includes a calculated and a measured rating, › the third includes a continuous scale instead of energy classes.

Energy classes, already used for household appliances, facilitate the comparison between buildings, because terms like primary and final energy are not familiar to many people. But they can also be a source of false interpretation as their content is different (e.g. because conditioned floor area and different uses are taken into account).

The figures that appear in the column to the left of the present text show examples of different ways to display the energy performance rating and classification that are used in the Member States.

3 > How the directive and Standard EN 15217 complement each other

Compared to the directive, EN 15217:

› provides more precise reference values (values per building class, energy classes) and recommendations (management),

› expresses the indicator in a form that is normalised by the conditioned floor area. Note that the conditioned area could be defined differently in different Member States.

The indicator is calculated according to EN 15603.

EN 15217, and especially the normative Annex A "Procedure for building energy certification documentation", can be used by authorities for setting up a procedure for building energy certification. It can contribute to reducing costs, if used as an alternative to developing separate energy certification procedures at the national level.

4 > FAQ

The requirements of the directive are subject to some interpretation at the national level. What are the main differences of between these interpretations?

The main differences between the Member States are:

› The application of the certificate either to the whole building, or to a part of a building (e.g. to a single flat). This means that a certificate is issued only if the whole bulding is sold or rented. This reduces the number of certificates and the information that is available. The revised version of the EPBD specifies that the certifcate must also be available when any part of the building is sold or rented.

› The choice of the rating indicator. Most of the Member States use the primary energy and/or CO2 emissions, but some countries use only the final energy. This could lead to false interpretation, as indicated in P150 (Numerical indicator for the energy performance based on primary energy use and CO2 emissions). The revised version of the directive requires the use of primary energy in an indicator but not for the energy rating (it should be remembered that the rating is not a requirement of the EPBD).


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› The evaluation methods. Most of the Member States developed national evaluation methods even though European Standards were available. Some methods are very detailed, some are very simplified. In some methods even generation losses are not taken into account. It is therefore impossible to compare the results between Member States.




Booklet 1


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Cluster Overall energy use and definition of energy

ratings

Introduction The Energy Performance of Buildings Directive (EPBD) requires a general framework and a methodology for calculating the integrated energy performance of buildings. The energy performance of a building is the amount of energy consumed or estimated to fulfil different energy requirements. This amount shall be reflected in one or more numeric indicators that take into account insulation, technical installation characteristics, design and sizing in relation to climatic variables. In order to be able to compare different energy sources, an aggregate value must also be calculated. European Standard EN 15603 covers this final step in the set of CEN standards that implement the EPBD. It defines a general framework for the assessment of overall energy use in a building, and the methods that should be used to calculate overall energy ratings. European Standard EN 15603 defines the energy services whose energy performance ratings must be determined in planned and existing buildings. Two principal types of energy rating for buildings are proposed in this standard:

› the calculated energy rating; › the measured energy rating. Information paper P88 gives a short introduction to CEN standard 15603. It explains the calculated energy ratings and provides detailed information on the input and output data and on links to the other CEN standards. Information paper P89 explains the measured energy rating.

Information papers IP 88 Information paper on Energy performance of buildings – Overall energy use

and definition of energy ratings – Calculated energy rating EN 15603 (Overall energy use)

IP 87 How to integrate the CEN-EPBD standards in national building regulations? The use of EN 15603 to adopt the same structure as starting point for coordination of Member

States regulations IP 89 Measured or operational energy performance of buildings Procedures for defining measured energy use and operational ratings and for presenting

measured energy performance results on building energy certificates Presentations Besides Information Papers, corresponding presentations have been prepared to support communication about EN EPBD standards as well as lectures. Presentations often include notes to explain the slides and to support lecture preparation. Presentations can also be downloaded freely from http://www.iee-cense.eu/


Booklet 1


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[European projects]

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Johann Zirngibl CSTB France


www.iee-cense.eu

cense More information can be found at the CENSE project website: www.iee-cense.eu Similar Information Papers on CENSE and/or other European projects can be found at the Buildings Platform website: www.buildingsplatform.eu

Calculation of overall energy use in buildings: prEN 15603, EN 15459, EN 15217

Calculation of delivered energy: EN 15316, prEN 15243, EN 15377, EN 15241, EN 15232, EN 15193

Calculation of energy need (heating, cooling): EN ISO 13790, EN 15255, EN 15265

Figure 1: EN 15603, covers the final stage of calculation and is based on results from other standards

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The present standard specifies a general framework for the assessment of overall energy use of a building, and the calculation of overall energy ratings in terms of primary energy, CO2 emissions and other parameters defined by national energy policy.

Separate standards calculate the energy consumption of services within a building (heating, cooling, hot water, ventilation, lighting) and produce results that are used here in combination to derive the overall energy use.

The assessment is not limited to the building alone, but takes into account the wider environmental impact of the energy supply chain.

Allowance is made for energy that may be generated within the building, or on its premises, whether it is used to offset fuel and power drawn from other sources or "exported" for use elsewhere.

2 6

7

8

1

3

9

4

5 6

Figure 2: Examples of energy flows across the system boundary. Key: 1: user; 2: storage; 3: boiler; 4: Fuel; 5: Electricity; 6: Auxiliary energy; 7: thermal solar collector; 8: photovoltaic panels; 9: boundary.

Figure 3: Illustration of the breakdown into energy needs and energy use in the differentparts of the technical building systems

This international standard is applicable to a part of a building (e.g. a flat), an entire building, or several buildings. It is up to national bodies to define under which conditions, for which purposes and for which types of building the various ratings apply.

The assessment of the energy performance of specific technical building systems is dealt with in the appropriate part of EN 15241, EN 15243 and EN 15316 series (see References).

The locally applicable values for factors and coefficients needed to calculate the primary energy consumption and CO2 emissions related to the energy policy must be defined in a national annex.

2 > Principle of the method

Energy uses

Any assessment of the annual energy used by the building must include the following services if they are present:

1. heating; 2. cooling and dehumidification; 3. ventilation systems and humidification; 4. domestic hot water; 5. lighting (optional for residential building); 6. other services (optional). Annual energy use must include auxiliary energy and the energy lost by all of these systems.

Assessment boundaries

The system boundary defines the rated object (e.g. flat, building). Inside the system boundary the system losses are taken into account explicitly, outside the system boundary they are taken into account in the conversion factor for the different energy carriers.

Energy can be imported or exported through the system boundary (see Figure 2). For active solar, wind or hydraulic energy systems, the incident solar radiation on solar panels or the kinetic energy of wind or water is not part of the energy balance of the building: only the energy output from these systems is part of the energy balance. Energy generated on the building site and exported is credited explicitly, provided it is exported for use elsewhere.

Calculation procedure

The calculation direction goes from the needs to the energy source (see Figure 3), e.g. from the building’s total energy needs to the primary energy.

EPBD Buildings Platform > P88_EN_CENSE_EN_15603 2

Specific electrical services (lighting, ventilation, auxiliary) and thermal services (heating, cooling, humidification, dehumidification, domestic hot water) are considered separately inside the building boundaries.

Any on-site energy production from locally available renewable resources and the disposition of the resulting energy are considered and reported separately.

Figure 4: The CEN-alternatives: holistic or simplified approach The recovered gains (green arrow)are either incorporated in the systempart (right side) or in the buildingpart (left side)

Figure 5: External building shell insulation

Calculation step

The annual overall energy use, primary energy and CO2 emission for the different energy services can be calculated in one of the following ways:

⎯ using annual average values; ⎯ by dividing the year into a number of calculation steps (e.g. successive

months, days, hours, etc.).

Calculation principles of the recovered gains and losses

The interactions between the different energy services (heating, cooling, lighting, etc.) are taken into account by calculating the heat gains and recoverable system losses that can have a positive and/or negative impact on the energy performance of the building.

Two approaches are envisaged for taking into account the recoverable thermal losses that are not initially included in the building energy needs at the starting point (see Figure 4):

- the holistic approach In the holistic approach the totality of the effects of the heat sinks and sources in the building and the technical building systems that are recoverable for space conditioning, are taken into account in the calculation of the thermal energy needs of the building.

- the simplified approach In the simplified approach the recovered system heat losses, obtained by multiplying the recoverable thermal system losses by a conventional recovery factor, are directly subtracted from the loss of each considered technical building system.

The choice may be different for different technical building systems and is determined at the national level. A more detailed introduction to the holistic versus simplified approach is given in Information paper P95.

3 > Description of the method.

The method takes into account the main relevant parameters that affect the performance of a building:

- the building thermal needs, - the technical building systems, - the energy carriers.

In order to obtain a logically structured method, the same outputs are defined, independently of the energy use (heating, cooling, etc.). The common outputs are:

- the thermal losses, - the recoverable thermal losses, - the electrical energy use.

3.1 Building thermal needs

This part of the method is defined in Clause 6.2 of EN 15603. The building thermal needs, the building thermal transfers and the building heat gains and recoverable thermal losses are derived.


The annual energy requirements are calculated according to the referenced ENs:

- thermal need for space heating (without humidification) EN ISO 13790 - thermal need for space cooling

(without dehumidification) EN ISO 13790

- thermal need for domestic hot water EN 16316-3-1 EN 15316-3.1 - heat transfer by transmission + ventilation of the

building when heating EN ISO 13790

- heat transfer by transmission + ventilation of the building when cooling

EN ISO 13790

- internal and solar heat gains of the building when heating

EN ISO 13790

- internal and solar heat gains of the building when cooling

EN ISO 13790

- recoverable thermal losses of technical building systems when heating

EN 15316

- recoverable thermal losses of technical building systems when cooling

EN 15243

- thermal energy for humidification EN 15241 - thermal energy for dehumidification EN 15243

Figure 6: Technical building system structure (principle)

Figure 7: Forced draught boiler

3.2 Technical building systems

The technical building systems (see Figure 6) are split up into two parts:

technical system thermal losses, electrical and auxiliary energy without building generation devices,

energy generation systems, following the way the real structure of a technical building system is represented. In general the distribution system is linked to a specific energy use (heating, hot water, etc.), whereas a generator can be used for several purposes (e.g. heating and hot water).

3.2.1 Technical system thermal losses, electrical and auxiliary energy without building generation devices

This part of the method is defined in Clause 6.3.1 of EN 15603. The system thermal losses without the building generation devices include the emission, distribution and storage losses (if not included in the generation part) of the considered system.

The thermal output of the cooling distribution system includes the thermal need for dehumidification.

The thermal output of the ventilation system includes the thermal need for humidification.

The necessary inputs are calculated according to the referenced ENs as indicated below: - thermal losses, aux. energy heating syst. without generat.

EN 15316-1

- thermal losses, aux. energy of cooling syst. without generation (including dehumidification)

EN 15243 EN 15241

- thermal losses, aux. energy of DHW system without gen. EN 15316-3-2 - energy use for ventilation and system thermal losses

(including humidification) EN 15241

- energy use for lighting and heat dissipated by lighting EN 15193

3.2.2 Energy generation systems

This part of the method is defined in Clause 6.3.2 of EN 15603. The thermal energy input of the distribution systems must be supplied by the thermal energy output of the building heat generation systems or by


energy supplied from outside the building (e.g. district heating).

In the case of more than one generator servicing the same distribution subsystem, the heat input to the distribution system is obtained according to the system design from the different building generation devices and from the energy supplied directly from outside the building.

For a heat pump the difference between the energy input and the thermal output plus the thermal losses is taken into account in the building energy balance either as heat recovery (inside the system boundary, e.g. heat extracted from ventilation exhaust air) or as renewable energy produced on the building site if the heat is collected through the system boundary (e.g. heat pump with a ground source heat exchanger).

3.3 Choice of energy (weighted energy ratings)

This part of the method is defined in Clause 8 of EN 15603. The input to the building generation system (the sum of the thermal and electrical outputs of the energy generation systems, the generator thermal losses and the auxiliary energy) must be supplied by the energy input of the different energy carriers and the renewable energies produced on the building site.

A building generally uses more than one energy carrier. Therefore, a unit common to all energy carriers must be used to aggregate the environmental impact, such as kWh of energy, kg CO2, etc.. The aggregated amount is called the energy rating.

The standard defines different aggregation methods, based on the following very different impacts of the use of energy carriers:

› Primary energy use; › Production of carbon dioxide; › A parameter defined by national energy policy. Cost is a parameter that may be used in the energy policy aggregation method.

An example of such values is given in Appendix E (informative) of the standard.

3.3 Report

This part of the method is defined in Clause 11 of EN 15603. This clause defines the content of the report on the assessment of the energy use of a building according to this standard.

The report must include the rating together with its confidence interval (when available). The minimum amounts of data to be reported are listed in Table 9 of EN 15603 for the calculated and measured rating.

Report- Table 9 EN 15603



For buildings with active renewable energy systems, it is recommended to report as a supplementary value the rating that would be obtained if the renewable energy systems were not present.

The table is structured taking into account the main parameters that affect the energy performance of a building (see also "Description of the method). With only a few values, it is possible to have an overview of the strengths and weaknesses of the energy balance of a building. This table is a useful basis for suggesting building upgrades.

The aggregated amount of energy (the rating) is used as input in EN 15217. That standard takes care of the final assessment of the building, the goal of the calculations: it offers ways of expressing the energy performance and the energy performance requirements and suggests content and format for the energy performance classification and certificate.

4 > FAQ

Why is EN 15603 considered to be a top standard?

EN 15603 structures the overall energy use calculation of the energy consumption and production in a building according to the requirements of the EPBD. It includes the thermal characteristics of the building shell, the heating and air-conditioning installation and the installed lighting.

Which calculations are made in EN 15603?

Only the aggregation of different energy carriers to one or more numeric indicators (e.g. primary energy, CO2 emissions) is defined in EN 15603. Other standards calculate the energy consumption or production in a building.

How can the results of the calculations in EN 15603 be used?

EN 15603 offers ways of expressing energy performance and suggests the content and format of energy performance. The aggregated value can be the basis for the rating according the standard EN 15217: “Energy performance of buildings – Methods for expressing energy performance and for energy certification of buildings”.

The report defined in Clause 11 of EN 15603 takes into account the main parameters influencing the energy performance of a building. With only a few values it is possible to obtain an overview of the strong and weak aspects of the energy balance of a given building. The information summarised in the report can be a useful basis for making recommendations when upgrading a building. This information should therefore be indicated in the certificates in addition to the aggregated value.

National Documents and Laws regulate the application in detail.

Where can the relevant adjustment factors be found?

The adjustment factors to be applied in the different ratings, as for example the primary energy factor or the CO2-emission coefficient, are defined at the national level. Informative values are given in EN 15603.

What is the difference between EN 15603 and CEN/TR 15615?

CEN/TR 15615 is a technical report that explains the relationship of the different standards covered by EN 15603.

5 > References 1. CEN/TR 15615: Explanation of the general relationship between various

European Standards and the Energy Performance of Buildings Directive (EPBD) – Umbrella Document. European Committee for Standardization (CEN), Brussels (2007)

2. EN 15603, Overall energy use and definition of energy ratings, CEN, January 2008 (see also Info Paper P87)

3. EN ISO 13790, Energy performance of buildings – Calculation of energy use for space heating and cooling, (see Info Paper P92)

4. EN 15193, Energy performance of buildings – Energy lighting requirements (see Info Paper P91)

5. EN 15217, Energy performance of buildings — Methods for expressing energy performance and for energy certification of buildings

6. EN 15232, Calculation methods for energy efficiency improvements by the application of integrated building automation systems

7. EN 15241, Ventilation for buildings - Calculation methods for energy losses due to ventilation and infiltration in commercial buildings (see Info Paper P111)

8. EN 15243, Ventilation for buildings – Calculation of room temperatures and of load and energy for buildings with room conditioning systems (see Info Paper P113)

9. EN 15316-1, Heating systems in buildings – Method for calculation of system energy requirements and system efficiencies – Part 1: General (see Info Paper P96)

10. EN 15316-2-1 Heating systems in buildings – Method for calculation of system energy requirements and system efficiencies Part 2-1 Space heating emission systems (see Info Paper P97)

11. EN 15316-4, Heating systems in buildings – Method for calculation of system energy requirements and system efficiencies Part 4: Space heating generation systems (see Info Paper P102 – P108)

12. EN 15316-2-3, Heating systems in buildings – Method for calculation of system energy requirements and system efficiencies Part 2-3: Space heating distribution systems (see Info Paper P98)


13. EN 15316-3, Heating systems in buildings – Method for calculation of system energy requirements and system efficiencies – Part 3: Domestic hot water systems (see Info Paper P99 - P101)

Disclaimer: CENSE has received funding from the Community’s Intelligent Energy Europe programme under the contract EIE/07/069/SI2.466698.

The content of this document reflects the author’s view. The author and the European Commission are not liable for any use that may be made of the information contained therein.

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The EPBD Buildings Platform has been launched by the European Commission in the frame of the Intelligent Energy – Europe, 2003-2006 programme. It is managed by INIVE EEIG (www.inive.org), on behalf of DG Energy and Transport. The information in this publication is subject to a Disclaimer and Copyright Notice; see http://www.buildingsplatform.eu/legal_notices_en.html © European Communities, 2009 Reproduction is authorised provided the source is acknowledged

http://www.buildingsplatform.eu/legal_notices_en.html


Booklet 1


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› Genersorted

› Calculation of ratings (weighted energy ratings); › Reporting.

The calculation direction in EN 15603 goes from the needs to the source, e.g. from the building energy needs to the primary energy (see example for space heating in figure 2). It follows the opposite direction of the physical energy flow in a building. Electrical services (such as lighting, ventilation, auxiliary) and thermal services (e.g. heating, cooling) are considered separately inside the building boundaries.

EPBD Buildings Platform > P087_EN_CENSE_EN_15603_Integration 2

3 > Building energy needs

The calculation starts with the building energy needs. The values related to the building energy needs are collected in table 4 of EN 15603.

In national building regulations the values in table 4/EN 15603 can be determined by national methods or ideally by EN standards. The values in EN 15603 are annual values. They can be calculated by simplified methods (e.g. monthly calculation step) or detailed methods (e.g. hourly calculation step). Elements having a major effect on the building energy needs such as thermal insulation, glazing, form factor etc., should be taken into account.

The values put in the following table could be issued by those methods.

C1 C2 C3 C3 C4

Heating

Cooling

Domestic hot water

sensible

heat latent heat

sensible heat

latent heat

L1 Building heat gains and recoverable thermal losses a)

- - -

L2 Building thermal transfers - - -

L3 Building thermal needs 14400

Not taken into

account in this

example

2100

a): if applicable Table 1: Building energy needs (example table 4/EN 15603, values in kWh/a)

The calculation then continues with the part related to the technical building systems.

4 > Technical building systems

In EN 15603 the technical building system losses are divided in two parts:

› Technical system thermal losses, electrical and auxiliary energy without building generation devices;

› Energy generation systems. Technical system thermal losses, electrical and auxiliary energy without building generation devices

The values related to the technical system thermal losses, electrical and auxiliary energy, taking into account emission, control and distribution, without building generation devices, are collected in table 5/EN 15603. The values in table 5/EN 15603 can be calculated according to available national methods or issued by tables like the following.

EN 15316-1 defines that for each sub-system, simplified (e.g. tabulated values) and/or detailed methods may be applied according to the accuracy required.

Different levels of details may be used for the different sub-systems of the heating system. However, it is essential that the results correspond to the defined output values of the sub-system in order to ensure proper links to calculations for the following sub-systems and development of a common structure.


Type of domestic hot water distribution

System thermal losses

(kWh/m2 a)

Recoverable system thermal loss (kWh/m2 a)

Electrical energy

(kWh/m2 a)

Collective with circulation 22,65 0,0 1,4

Alternatives, e.g.:

Collect. without circulation 10,8 3,7 0

Individual 3,8 2,0 0

Table 2a: System thermal losses, recoverable system thermal loss and electrical energy for DHW distribution; simple example, energy per m2 floor area.

Type of ventilation distribution System thermal losses (kWh/m2 a)

Electrical energy (kWh/m2 a)

Mechanical ventilation system – not balanced

0,0 4,0

Alternatives, e.g.:

Mechanical ventilation system – balanced (heat recovery eff. >60%)

- inside thermal insulation 0,0 6.0

- outside thermal insulation 4,3 6.0

Table 2b: System thermal losses and electrical energy for ventilation distribution; simple example, energy per m2 floor area.

Based on these examples and for a building with 100 m2 floor area, with:

› a collective domestic hot water system with circulation; › a non balanced mechanical ventilation system; › a heating system with distribution losses amounting e.g. 2020 kWh

table 5/EN 15603;

can be completed like follows.

C1 C2 C3 C4 C5

Heating Cool.

Domestic Hot water

Ventilation Lighting

L4 Electrical energy 190 140

(1,4x100) 400

(4,0x100)

Not taken into account inthis example

L5 System thermal losses

2020 2265

(22,65x100) 0

Not taken into account inthis example

L6 Recoverable system thermal losses

L7 Thermal input distribution

16420 (14400+2020)

4365 (2100+2265)

Table 3: System thermal losses and auxiliary energy without generation (example table 5/EN 15603, values in kWh/a)

Energy generation systems

Following the physical structure of heating systems, the heat input to the distribution system is dispatched, according to the system design, to the different energy generation systems and/or the energy supplied directly from outside the building (e.g. electricity, district heating). In EN 15603


the values related to the energy generation systems are collected in table 6/EN 15603.

As a first step, the required values in table 6 of EN 15603 could be determined according to national methods (efficiencies are convert to losses at each subsystem level).

C1 C2 C3

Type of generator LT Gas boiler Solar panel Grid electr.

Distribution systems supplied Heating /DHW DHW

L8 Thermal output 19655 (16420+4365-1130) 1130 -

L9 Auxiliary energy (*) 80 80 -

L10 System (generator) thermal losses 3734

L11 Recoverable system thermal losses

L12 Energy input 23389 0 890

L13 Electricity production

L14 Energy carrier gas solar electricity

(*): for the generator Table 4: Energy generation system (example table 6/EN 15603, values in kWh/a)

5 > Calculation of ratings (weighted energy ratings)

A building generally uses more than one energy carrier. Therefore, a common expression of all energy carriers shall be used to aggregate the used amounts.

According to EN 15603 the aggregation methods are based on:

› Primary energy; › Production of carbon dioxide; › A parameter defined by national energy policy. Cost is a parameter that may be used in the energy policy aggregation method.

The values related to the weighted ratings are collected in table 8/EN 15603. Informative values for primary energy factors and CO2 production coefficients are given in annex E table E1/EN 15603.

Informative values Primary energy factors fPCO2 production coefficient K

Non-renewable Total [kg/MWh]

Fuel oil 1.35 1.35 330

Gas 1.36 1.36 277

Anthracite 1.19 1.19 394

Wood shavings 0.06 1.06 4

Electricity from hydraulic power plant 0.50 1.50 7

Electricity Mix 3.14 3.31 617

Table 5: Informative Primary energy factors and CO2 coefficients in EN 15603 (extract)


For a building using:

› natural gas; › solar panels; › grid electricity;

the primary energy rating according table 8/EN 15603 can be completed like follows.

Row C1 C2 C3

Delivered energy

Gas Solar Electricity

L1 Energy delivered (unweighted) 23389 1130 890

L2 Weighting factor or coefficient 1,36 0 3,14

L3 Weighted delivered energy or CO2 31809 0 2794

Exported energy

thermal electrical

L4 Energy exported (unweighted)

L5 Weighting factor

L6 Weighted exported energy or CO2 0

L7 Rating 34603 (31809+2794)

Table 6: Calculation of ratings (example table 8/EN 15603, values in kWh/a)

6 > Reporting

EN 15603 defines the content of the report on assessment of energy use of buildings. This report resumes the main parameters influencing the energy performance of a building. The report is also part of the general structure that should be respected by national building regulations.

With only a few values it is possible to get an overview of the weak and strong points in the energy balance of a building.

The values of this example are indicated in table 7.


Building thermal needs

(without techn. build. systems)

Technical building systemperformance

(thermal system losses- recovered losses)

Energy delivered (content of energy carriers )

Energy rating (Weighted Energy carriers)

Heating: 14400 Hot water: 2100 Cooling: -

Heat (H+W): 8019 (2020+2265+3734) Cooling: Electricity *): Heat auxiliary 490 (190+140+80+80) Cooling auxiliary Lighting Ventilation 400

Gas 23389 Oil Electricity 890 District heating Etc.

Gas 31809 Electricity 2794

Energy exported (Unweighted energy carriers)

Thermal:

34603

Renewable energy produced on site

Thermal 1130

Electrical

15316-4HEATING SYSTEM

HEAT GENERATION

15316-4-1BOILERS

15316-4-2HEAT PUMPS

15316-4-3THERMAL SOLAR

15316-4-4CHP

15316-4-5DISTRICT HEATING

15316-4-6PHOTOVOLTAIC

15316-4-7BIOMASS

15316-4-8AIR HEATERS

15316-4HEATING SYSTEM

HEAT GENERATION

15316-4-1BOILERS

15316-4-2HEAT PUMPS

15316-4-3THERMAL SOLAR

15316-4-4CHP

15316-4-5DISTRICT HEATING

15316-4-6PHOTOVOLTAIC

15316-4-7BIOMASS

15316-4-8AIR HEATERS

Figure 3: Energy generation standards available developed by CEN; example for heating systems

*) includes electricity for ventilation, lighting and the auxiliary energy for thermal systems; does not include electricity for heating, cooling, DHW, humidification and dehumidification.

Table 7: Reporting overall energy use (example table 9 EN 15603, values in kWh/a)

7 > How to fill in the general structure?

The example before has shown that the general structure defined in EN 15603 is:

› well structured with defined inputs and outputs; › simple, complete and consistent, starting from the product standards

until and including the overall energy use; › flexible, because only the method is standardised. The method can be

parametered at national level by national annexes. Simplified and detailed methods can be used, because different uses require different methods.

The general structure can gradually be filled in by the Member States:

› as a first immediate step, with national methods; › then, with CEN standards (with or without national annexes). It is also possible to mix up CEN standards for some modules and national methods for other modules. For example for the energy generations systems different CEN standards are available (see figure 3). If a Member State prefers, for the time being, to use national methods, the CEN standards can be replaced by national methods but the national method must provide the standardised outputs of the CEN standards in order to be integrated in the general approach.

8 > FAQ

Why the general structure defined in EN 15603 could fit to most existing building regulation? Is it reliable?

The general structure defined in EN 15603 is a very simple structure based on the physical description of the major effects on the building energy


performance. In mostly all existing or foreseen national building regulations in the Member States the calculation starts with the calculation of the building needs and then efficiencies or losses are added for the various parts of the technical building systems.

The basic "connection points" to the general structure are: - the energy needs; - the distribution input; - the generation input (the delivered energy); - the weighted energy (rating).

EN 15603 has a consistent and flexible structure, adapted for simplified methods and for more detailed methods. The structure is based on the physical description of a building and the technical building system and integrates the results of subsequent standards in the overall energy use.


Are there already some experiences for the implementation of EN 15603, and the defined structure, on national level?

In Italy the use of European standards is well advanced. Even software is already available. In Switzerland documents are prepared to implement EN 15603. Also other countries intend to adopt the structure (The Netherlands, Germany, see also Information Paper P90)

Where do the outputs needed to fill in the general structure come from? From tabulated values or from calculation methods?

Both approaches are possible. The method chosen depends on the accuracy required which depends on the application (e.g. first assessment at preliminary stage, rough method for existing single family houses with simple and comparable design). The required data and accuracy is also related to building elements which have major or minor effects on the building energy performance.

9 > References 1. EN 15603, Overall energy use and definition of energy ratings, CEN, January

2008 2. EN 15316-1, Method for calculation of system energy requirements and

system efficiencies – General part, CEN, July 2007

Disclaimer: CENSE has received funding from the Community’s Intelligent Energy Europe programme under the contract EIE/07/069/SI2.466698.

The content of this document reflects the author’s view. The author and the European Commission are not liable for any use that may be made of the information contained therein.

cense


The EPBD Buildings Platform has been launched by the European Commission in the frame of the Intelligent Energy – Europe, 2003-2006 programmes. It is managed by INIVE EEIG (www.inive.org), on behalf of DG Energy and Transport. The information in this publication is subject to a Disclaimer and Copyright Notice; see http://www.buildingsplatform.eu/legal_notices_en.html © European Communities, 2009 Reproduction is authorised provided the source is acknowledged

http://www.buildingsplatform.eu/legal_notices_en.html


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An energy certificate based on measured energyfor existing buildings where it must be on permadisplay to the public. Renewal of a measured enis a practical and cost effective method to motivoperators and occupiers to improve their operatiobtain public recognition of these efforts in the

For organisations with a portfolio of buildings, cemeasured energy provide a simple, low cost meabuildings should be targeted for more detailed asaving potential.

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overall energy use per unit of useful floor area of a building based on the delivered and exported energy and accounting for energy generated in the building.

The total weighted energy (or its components such as the electricity or fossil fuel use) can be compared with suitable benchmarks to rank the building against its peers and/or to place it in an energy efficiency class defined at the national level, eg A to G.

The assessment should be accompanied by recommended measures for improving the energy efficiency of the building cost effectively.

Energy certificates based on measured energy can show the following energy performance indicators: › The total weighted energy

normalised per unit floor area eg kg CO2/m2/year

› A numerical rating as a non-dimensional index relative to a benchmark and/or as an absolute value

› A class or grade eg on an A to G scale

› The total use of electricity in kWh/m2/year and a rating relative to a benchmark

› The total fuel and thermal energy use in kWh/m2/year and a rating relative to a benchmark

› The total absolute weighted energy eg tonnes CO2 per year

› The energy performance for previous years

3 > How to assess and report measured energy

Measured data must be adjusted to 365 days, taking account of the weather dependency of energy used for heating and cooling, so there should be a tolerance level imposed for the measurement period. For buildings using more than one energy carrier, there needs to be a synchronicity requirement for the measurement period of each energy carrier ie a minimum number of common days.

The annual energy consumption of a building might include energy used by a special energy use not common in a given category of building and hence not taken into account in the building’s benchmark. If this special energy is metered, it can be deducted from the total before making the comparison with the benchmark.

The total overall energy use of the building can be expressed as a single parameter using units of primary energy, carbon dioxide emission or other energy carrier weightings defined by national policy. For buildings with active renewable energy sources, it is recommended to report as a supplementary value the energy that would be used if there were no renewable energy generated within the system boundary. The total energy used by the building systems, including any renewables, defines the building’s energy efficiency.

4 > Benchmarks for measured energy assessments

A taxonomy of building categories must be developed for the specific purpose of benchmarking measured energy. Ideally energy data would be collected from a statistically significant sample of each building category over a trial year to generate up to date and robust benchmarks. The benchmarks can be further developed to take account of climate, hours of use and the density of occupation: it is not fair to penalise a densely occupied or 24/7 building nor to favour a half empty one or one used for only 10 hours per week.

Benchmarks should be expressed in terms of delivered energy used per unit of floor area (kWh/m2), separately for electricity and non-electrical energy. The conversion factors for energy weighting are defined separately as the benchmarks are specified in energy terms.

To improve the comparison of the actual energy use with the benchmark, the benchmark can be brought into line with the metered building by adjustments for weather and for occupancy duration, if valid data are available and the occupied hours are greater than the values expected for the benchmark building.

If data on delivered energy to buildings is collected by public authorities (together with heated surface and supplied services, i.e. heating and/or dhw and/or cooling...), a simple statistical analysis will identify the high energy consuming buildings. The highest consumption buildings, for example, the top decile or quartile depending on resources, should be prioritised to receive a detailed energy audit, as they are the most likely to have considerable opportunities for cost effective energy conservation

CENSE > P089_EN_CENSE_Measured_energy 2

measures.

Energy certificate based on measured energy use displayed in public buildings in the UK. The headline rating is based onthe “energy efficiency of the building”, defined as the ratio of the actual CO2 emissions compared with a benchmark applicable to that building category. The certificate also shows the total CO2 emissions, in tonnes per year, and how the rating and emissions have changed over the last three years.

Energy certificate based on measured energy use displayed in public buildings in Germany (partly translated). The certificate shows information on the building, the issuer and separate energy performance indicators for fuel/heat and electricity, together with benchmarks, on a dashboard style scale.

5 > Mixed use buildings and multi-building sites

For mixed-use buildings, ie those comprising more than one benchmark category, the whole building’s metered energy consumption should be compared with a whole building benchmark comprised of an average of all the categories weighted by floor area. This is especially useful when buildings include high energy intensity uses such as retail outlets, restaurants or swimming pools.

By the same principle, CEN Standard EN 15217 states that an energy certificate can be applied to a group of buildings, served by common energy systems and meters, if no more than one building has an area of more than 1,000 m2. Whole-site energy certificates have much merit. The procedure captures the total carbon footprint of the site, aligns the system boundary with the supplier’s energy meters and subjects the whole site to energy efficiency scrutiny. By contrast, a methodology which covers only those buildings over 1,000 m2, omits the rest. Furthermore, whole-site energy certificates can be displayed in the public reception areas for the site and give the most meaningful information to the public.

6 > How to improve measured energy performance

Reductions in the energy used by buildings (and the resultant carbon emissions) are possible through fine-tuning and better control, management and maintenance by managers, users and contractors.

A significant contributor to the poor energy performance of commercial buildings is the relatively devalued role of the building manager, resulting from the often inadequate priority given to it by the building’s owner/agent. The person responsible for a building’s energy efficiency needs enthusiasm, commitment, motivation, charisma and authority to make sure energy efficiency happens. If sustainable operation of buildings is made a critical key performance indicator, and if far greater priority is given in terms of resources, this would turn around operational performance.

In all buildings, but especially simple ones, encouraging energy-wise occupant behaviour is the first step (and reflects the need for the charismatic energy manager). At the same time, energy cost accounting needs to ensure that those making savings see a financial benefit. The next thing to tackle is incorrectly or inefficiently programmed HVAC and lighting controls. Problems are legion: poor commissioning, lack of understanding of design intent, set points adjusted liberally in response to complaints or one-off events and not reset, unmanageable complexity, etc. Sustaining these no- and low-cost measures is also crucial, and reinforced by an annual renewal of the energy certificate. Lastly, a gradual programme of investment in new, more efficient plant, controls and even fabric should be rolled out to deal with inefficient equipment, bad design, unmaintainable plant, poorly located or insufficient sensors, poor zoning, conflicts or self-contradictions in design intent and so on.


Application example: sizing the heat generator

0

20

40

60

80

100

120

140

-10,0 -5,0 0,0 5,0 10,0 15,0 20,0External temperature [°C]

[kW] Boiler sizing with energy signature method

STARTING POINT 0 kW @ 17 C

POINT ACCORDING TO YEARLY AVERAGE BOILER POWER (50 kW)

AND EXTERNAL TEMPERATURE (7 C)

DESIGN EXTERNAL TEMPERATURE: -5 C

BOILER SIZING110 kW

The energy signature shown in the main text has been used to size the heat generator. The old generator was 250 kW, the new one is 116 kW. Application example: checking the design – 40 flats in northern Italy

Design versus actual energy signature

0

20

40

60

80

100

120

140

160

180

0 5 10 15 20 25 30External temperature °C

Del

iver

ed p

ower

kW

Actual energy signature kWDesign energy signature kW

The comparison between design energy signature and actual operating data shows that the designed performance has not been reached. At 5 °C the expected power according to design is 95 kW whilst the actual power is 140 kW, that is 40…50% more. Changes in the energy signature after any energy conservation measure gives visual evidence of their effectiveness (or not).

7 > A practical tool to report and check measured energy

Annex B of EN 15603 contains a practical tool to help identify the actual energy performance of buildings, separate the influence of weather and help with energy conservation measures follow–up. It is called the energy signature method.

Basically, energy signature is a plot of average delivered power to the building versus average external temperature. An energy signature can easily be produced based on some readings of the energy meters. An example of such a plot is given below.

Energy signature - 16 flats central heating Old building in northern Italy - 2400 °Cday

0

20

40

60

80

100

-10 -5 0 5 10 15 20External temperature °C

Dei

vere

d po

wer

kW

Measured data kWYearly averageLineare (Measured data kW)

The input data consists of some readings of the fuel and/or electric energy meters and corresponding actual climatic data. Based upon this technique, several performance metrics can be diagnosed:

› The generator sizing can be checked by extending the energy signature plot up to the design external temperature;

› The effect of any operational change, energy conservation measure or alteration of the building and systems can be graphically and quantitatively highlighted;

› A "design energy signature" can be calculated according to monthly design data. Plotting actual operation points on the design energy signature shows graphically if the design objectives have been reached.

8 > References 1. EN 15603 Overall energy use and definition of energy ratings, January 2008 C

TIDEAHVIL O

2. EN 15217 Methods for expressing energy performance and for energy certification of buildings, June 2007

cense

ENSE partners: NO (NL; coordinator), CSTB (FR),

SSO (NL), Fraunhofer-IBP (DE), TU (DK), ESD (GB), FAMBSI (FI), DC (IT) ssociated partners: TA Luzern (CH), BRE (GB), iessmann (DE), Roulet (CH), JRC

ES (EC) ink: www.iee-cense.eu

riginal text language: English


