CEN/TC 371 N 260. N260 - EPBD Overarching Standard for dispatch of ENQ draft to CMC. Document type: Other meeting document

Transcription

1 CEN/TC 371 N 260 CEN/TC 371 CEN/TC Project Committee - Energy Performance of Building project group of secretary: klaas.dewinkel@nen.nl Secretariat: NEN (Netherlands) N260 - EPBD Overarching Standard for dispatch of ENQ draft to CMC Document type: Other meeting document Date of document: Expected action: MEET Background: Committee URL:

2 CEN/TC 371 Date: pren O.A.:2012 CEN/TC 371 Secretariat: NEN Energy performance of buildings Overarching standard EPBD Einführendes Element Haupt-Element Ergänzendes Element Élément introductif Élément central Élément complémentaire ICS: Descriptors: Replaces EN 15603:2008 Document type: European Standard Document subtype: Document stage: CEN Enquiry Document language: EN STD Version 2.4a

3 pren O.A.:2012 (E) Draft Contents Page Foreword...5 Introduction Scope Normative references Terms and definitions Buildings Technical building systems Inspection of technical building systems Energy Energy ratings and certification Costs Energy calculation Symbols, units, subscripts and abbreviations Framework of the assessment of energy performance of buildings Routing Types and uses of ratings The over-arching reference modular structure Assessment of energy performance of buildings General Building categories Building services Assessment boundaries General principles The conditioned space of the assessed building or building unit The building site ( on site ) Outside the building site Energy balance Primary energy balance Energy flows Additional performance indicator: share of renewable General principles Conventions on the energy from renewable energy source (E ren ) Energy performance indicators for technical building systems Calculated energy rating routing Calculation procedure General Calculation step Calculation principles of the recovered gains and losses Effect of integrated control Overall calculation procedure Partitioning General Partitioning criteria Partitions as groups of elementary spaces Subdivision and distribution rules Connected hierarchy Partitioning criteria details Technical systems calculation structure

4 Draft pren O.A.:2012 (E) 10.1 General Ventilation systems calculation structure Building spaces partitioning according to ventilation Ventilation sub-system calculation structure Heating system calculation structure Heating system zones Heating sub-systems calculation structure Domestic hot water system calculation structure Domestic hot water system zones Domestic hot water system calculation structure Cooling system calculation structure Cooling systems zones Cooling systems calculation structure Lighting zones Calculated energy performance General Non electric delivered energy Electric energy balance General Calculation procedure Exported heat on-site produced and not included in thermal use of the building Building thermal needs Technical building systems Technical system thermal losses, electrical and auxiliary energy without building generation devices Thermal energy generation systems Operating conditions Climatic and external environment data Measured energy rating and comparison with calculations Common over-arching output General General Tabulated overview of the amounts of energy per energy carrier and energy service Absolute values Annex A (normative) Default options and values A.1 General provisions for national adaptation A.2 Type of ratings according to building type and assessment purpose A.3 Building categories A.4 Building services included in the energy performance calculation A.5 Assessment boundaries A.5.1 The conditioned space of the assessed building or building unit A.5.2 The building site ( on site ) A.6 Overheads included in the primary energy factors A.7 Primary energy factors A.8 Energy flows to be included in the energy balance A.9 Renewable energy flows part of the renewable energy ratio calculation A.10 Other data A.11 Distribution rules criteria Annex B (normative) Use of subscripts B.1 Introduction B.2 Order of subscripts B.3 Terms for subscripts B.4 Further levels of subscripts B.5 Other common subscripts B.6 Examples and comments B.6.1 Heat quantities in a building B.6.2 Heat (Q) or energy (E) quantities in a technical building system B.6.3 Energy outside a building

5 pren O.A.:2012 (E) Draft B.6.4 Primary energy B.6.5 Extra levels B.6.6 Example illustrating the use of common symbols and subscripts in the EPBD related EN standards B.7 Properties and case identifiers Annex C (normative) Building partitioning criteria C.1 Building units C.1.1 General C.1.2 Distribution rule C.1.3 Subdivision rules C.2 Operating zones C.2.1 General C.2.2 Subdivision rules C.2.3 Distribution rules C.3 Heating needs zones C.3.1 General C.3.2 Sub-division rule C.3.3 Distribution rule C.4 Cooling needs zones C.4.1 General C.4.2 Sub-division rule C.4.3 Distribution rule C.5 Domestic hot water needs balance C.5.1 General C.5.2 Sub-division rule C.5.3 Distribution rule C.6 Ventilation zones C.6.1 General C.6.2 Sub-division rule C.6.3 Distribution rule C.7 Humidification/dehumidification Annex D (informative) Alphabetical index of terms D.1 Alphabetical list of terms defined D.2 List of English, French and German terms used for symbols D.3 List of English, French and German terms used for subscripts Bibliography

6 Draft pren O.A.:2012 (E) Foreword This document (pren OA:2012) has been prepared by Technical Committee CEN/TC 371 Energy Performance of Buildings Project Group, the secretariat of which is held by NEN. This document is currently submitted to the CEN Enquiry. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association (Mandate M/480, [2]), and supports essential requirements of EU Directive 2010/31/EC on the energy performance of buildings (EPBD). It forms part of a series of standards aimed at European harmonisation of the methodology for the calculation of the energy performance of buildings. 5

7 pren O.A.:2012 (E) Draft Introduction Energy assessments of buildings are carried out for various purposes, such as: a) judging compliance with building regulations expressed in terms of a limitation on energy use or a related quantity; b) increasing transparency in commercial operations through the energy certification and/or display of a level of energy c) monitoring of the energy efficiency of the building and its technical building systems; d) helping in planning retrofit measures, through prediction of energy savings which would result from various actions. This standard specifies a general framework for the assessment of overall energy use of a building, and the calculation of energy ratings in terms of primary energy or other energy related metrics. Separate standards provide methodologies that may be uses to calculate the energy use of services within a building (heating, cooling, hot water, ventilation and lighting) and produce results that are used here in combination to show overall energy use. This assessment is not limited to the building alone, but takes into account the wider environmental impact of the energy supply chain. This standard replaces EN 15603:2008 and parts of other EN or EN-ISO standards published in under the mandate M/343 on the EPBD. This revision was required as a result of the EPBD recast (2010/31/EU).The set of standards developed under mandate M/343 will be revised to become consistent with this overarching standard under mandate M/480. For many of these standards the revisions are mainly editorial plus changes to make the procedures unambiguous and software proof and to rationalize the choices. More information is provided in the Technical Report accompanying this standard (EN TR OA, under preparation). To provide flexibility to the EU Member States in the application of the set of CEN standards, clearly identified options are given, with a rational for the choices. In order to progress on harmonization, reproducibility and transparency default CEN options are provided at relevant positions in the standards. At national level these default CEN options may be replaced by a National Annex, following the models provided in the relevant standards. 6

8 Draft pren O.A.:2012 (E) 1 Scope This standard provides a systematic, comprehensive and modular overall structure on the integrated energy performance of buildings, in order to ensure consistency among all CEN standards required to calculate the energy performance of buildings according to the EPBD (2010/31/EU). This standard handles the framework of the overall energy performance of a building, covering inter alia: a) common terms, definitions and symbols; b) building and system boundaries; c) building partitioning; d) methodology for calculating the energy performance of a building (set of overall equations on energy used, delivered, produced and/or exported at the building site and near-by); e) set of overall equations and input-output relations, linking the various elements relevant for the assessment of the overall energy performance of buildings which are treated in separate standards; f) general requirements to standards dealing with partial calculations; g) general rules in setting out alternative calculation routes according to the calculation scope and requirements; h) rules for the combination of different partitioning; i) performance indicators; j) methodology for measured energy performance assessment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. CEN/TS BP, Energy Performance of Buildings Basic principles for the set of EPBD standards (in preparation) CEN/TS DTR, Energy Performance of Buildings Detailed technical rules for the set of EPBD standards (in preparation) EN ISO 7345:1995, Thermal insulation Physical quantities and definitions ISO 13600:1997, Technical energy systems Basic concepts EN ISO 13790, Energy performance of buildings Calculation of energy use for space heating and cooling EN 15241, Ventilation for buildings Calculation methods for energy losses due to ventilation and infiltration in commercial buildings EN 15243, Ventilation for buildings Calculation of room temperatures and of load and energy for buildings with room conditioning systems EN 15316, Heating systems in buildings Method for calculation of system energy requirements and system efficiencies EN ISO 15927, Hygrothermal performance of buildings Calculation and presentation of climatic data 7

9 pren O.A.:2012 (E) Draft 3 Terms and definitions For the purposes of this European Standard, the terms and definitions given in EN ISO 7345:1995 and the following apply. Given the scope of this over-arching standard, these definitions are applicable to all standards that are necessary to assess the energy performance of buildings. 1 The terms and definitions are adopted from CEN TR 15615:2008 and correspond with the terms and definitions in EN 15603: An alphabetic list of all terms defined in this clause is given in D. 3.1 Buildings building construction as a whole, including its envelope and all technical building systems, for which energy is used to condition the indoor climate, to provide domestic hot water and illumination and other services related to the use of the building The term can refer to the building as a whole or to parts thereof that have been designed or altered to be used separately building automation and control products, software, and engineering services for automatic controls, monitoring and optimization, human intervention, and management to achieve energy-efficient, economical, and safe operation of building services equipment building category classification of buildings and/or building units and/or building spaces related to the use building element technical building system or an element of the building envelope building services services provided by technical building systems and by appliances to provide acceptable indoor climate conditions, domestic hot water, illumination levels and other services related to the use of the building building unit section, floor or apartment within a building which is designed or altered to be used separately conditioned area floor area of conditioned spaces excluding non-habitable cellars or non-habitable parts of a space, including the floor area on all storeys if more than one Internal, overall internal or external dimensions can be used. This leads to different areas for the same building. Some services, such as lighting or ventilation, might be provided to areas not included in this definition (e.g. a car park). The precise definition of the conditioned area is given by national authorities. 8

10 Draft pren O.A.:2012 (E) 4 Conditioned area can be taken as the useful area mentioned in the Articles 5, 6 and 7 of the EPBD1) unless it is otherwise defined in national regulations conditioned space ventilated and/or, heated and/or cooled and/or lighted space for human occupancy The heated and/or cooled spaces are used to define the thermal envelope conditioned zone part of a conditioned space with a given set-point temperature or set-point temperatures, throughout which there is the same occupancy pattern and the internal temperature which is controlled by a single heating system, cooling system and/or ventilation system cooled space room or enclosure which for the purposes of a calculation is assumed to be cooled to a given set-point temperature or set point temperatures dehumidification process of removing water vapour from air domestic hot water heating process of heat supply to raise the temperature of the cold water to the intended delivery temperature existing building for calculated energy rating: building that is erected for measured energy rating: building for which actual data necessary to assess the energy use are known or can be measured external dimension dimension measured on the exterior of a building heated space room or enclosure which for the purposes of a calculation is assumed to be heated to a given set-point temperature or set point temperatures humidification process of adding water vapour to air to increase humidity internal dimension dimension measured from wall to wall and floor to ceiling inside a room of a building lighting process of supplying illumination 1 ) Directive 2002/91/EC of the European Parliament and of the Council of 16 December 2002 on the energy performance of buildings 9

11 pren O.A.:2012 (E) Draft new building for calculated energy rating: building at design stage or under construction for measured energy rating: building recently constructed without reliable records of energy use occupied zone part of a conditioned zone in which persons normally reside and where requirements as to the indoor environment are to be satisfied The definition of the occupied zone depends on the geometry and the use of the room and is specified case by case. Usually the term occupied zone is used only for areas designed for human occupancy and is defined as a volume of air that is confined by specified horizontal and vertical planes. The vertical planes are usually parallel with the walls of the room. Usually there is also a limit placed on the height of the occupied zone other services services supplied by energy consuming appliances overall internal dimension dimension measured on the interior of a building, ignoring internal partitions space cooling process of heat extraction for thermal comfort space heating process of heat supply for thermal comfort technical building sub-system part of a technical building system that performs a specific function (e.g. heat generation, heat distribution, heat emission) technical building system technical equipment for heating, cooling, ventilation, domestic hot water, lighting and electricity production A technical building system can refer to one or to several building services (e.g. heating system, heating and DHW system). A technical building system is composed of different subsystems. Electricity production can include cogeneration and photovoltaic systems thermal envelope area total of the area of all elements of a building that enclose conditioned spaces through which thermal energy is transferred to or from the external environment or to or from unconditioned spaces 1 2 Thermal element area depends on whether internal, overall internal or external dimensions are being used. The respective areas of the building envelope may be weighted with a (nationally fixed) reduction factor in case of e.g. unheated adjacent spaces and ground floors unconditioned space room or enclosure which is not part of a conditioned space 10

12 Draft pren O.A.:2012 (E) ventilation process of supplying or removing air by natural or mechanical means to or from a space Such air is not required to have been conditioned. 3.2 Technical building systems air conditioning system combination of all components required to provide a form of air treatment in which temperature is controlled, possibly in combination with the control of ventilation, humidity and air cleanliness auxiliary energy electrical energy used by technical building systems for heating, cooling, ventilation, lighting and/or domestic water to support energy transformation to satisfy energy needs 1 2 This includes energy for fans, pumps, electronics, etc. Electrical energy input to the a ventilation system for air transport and heat recovery is not considered as auxiliary energy, but as energy use for ventilation In EN ISO 9488, Solar energy Vocabulary, the energy used for pumps and valves is called "parasitic energy" cogeneration simultaneous generation in one process of thermal energy and electrical or mechanical energy Also known as combined heat and power (CHP) demand controlled ventilation ventilation system in which the room airflow rate is governed by an automatic control depending on occupancy and an indoor air quality indicator (CO 2, H 2 O, or pollutant) 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) part load operation operational state of a technical system (e.g. heat pump), where the actual load is below the actual output capacity of the device recoverable system thermal loss part of a system thermal loss which can be recovered to lower either the energy need for heating or cooling or the energy use of the heating or cooling system This depends on the calculation approach chosen to calculate the recovered gains and losses (holistic or simplified approach) recovered system thermal loss part of the recoverable system thermal loss which has been recovered to lower either the energy need for heating or cooling or the energy use of the heating or cooling system This depends on the calculation approach chosen to calculate the recovered gains and losses (holistic or simplified approach). 11

13 pren O.A.:2012 (E) Draft room conditioning system system capable of maintaining comfort conditions in a room within a defined range. Such systems comprise air conditioning and surface based radiative systems system thermal loss thermal loss from a technical building system for heating, cooling, domestic hot water, humidification, dehumidification or ventilation that does not contribute to the useful output of the system A system loss can become an internal heat gain for the building if it is recoverable Thermal energy recovered directly in the subsystem is not considered as a system thermal loss but as heat recovery and directly treated in the related system standard. Heat dissipated by the lighting system or by other services (e.g. appliances of computer equipment) is not part of the system thermal losses, but part of the internal heat gains ventilation heat recovery heat recovered from the exhaust air to reduce the ventilation heat transfer 3.3 Inspection of technical building systems commissioning sequence of events to enable the functioning of a building and its heating, ventilation, room conditioning (HVAC) system and lighting in accordance with the design parameters design criteria set of descriptions based on a particular environmental element such as indoor air quality, satisfactory lighting, thermal and acoustical comfort, energy efficiency and associated system controls to be used for assessing plant operation design documentation written description of the essential design elements of a plant energy inspection examination of heating, room conditioning systems and/or lighting in a building inspector person having appropriate training or practical experience in energy inspection of heating, room conditioning systems and/or lighting and associated regulations for energy room conditioning system control measures taken to enable operation of a system in accordance with the design criteria It can be a part of the building automation and control system. 3.4 Energy assessment boundary boundary where the energy balance of delivered and exported energy is defined 12

14 Draft pren O.A.:2012 (E) building site on site building and the premises on which the building is located CO 2 emission coefficient given energy carrier, quantity of CO 2 emitted to the atmosphere per unit of delivered energy The CO 2 emission coefficient can also include the equivalent emissions of other greenhouse gases (e.g. methane) delivered energy energy, expressed per energy carrier, supplied to the technical building systems through the system boundary, to satisfy the uses taken into account (heating, cooling, ventilation, domestic hot water, lighting, appliances etc.) or to produce electricity For active solar and wind energy systems the incident solar radiation on solar panels or on solar collectors or the kinetic energy of wind is not part of the energy balance of the building. It is decided at national level whether or not renewable energy produced on site is part of the delivered energy. Delivered energy can be calculated for defined energy uses or it can be measured. Lighting fitted to the outside of the building envelope is not part of the EP uses (assessment) distant to the building site outside the assessment boundaries and outside the building site Energy sources which are not distributed through a specific network to the assessed building or building unit and which are not designed for a particular building site electricity grid public electricity network energy carrier substance or phenomenon that can be used to produce mechanical work or heat or to operate chemical or physical processes [ISO 13600:1997] 1 2 The energy content of fuels is given by their gross calorific value. The energy need can include additional heat transfer resulting from non-uniform temperature distribution and non-ideal temperature control, if they are taken into account by increasing (decreasing) the effective temperature for heating (cooling) and not included in the heat transfer due to the heating (cooling) system energy need for domestic hot water heat to be delivered to the needed amount of domestic hot water to raise its temperature from the cold network temperature to the prefixed delivery temperature at the delivery point energy need for heating or cooling heat to be delivered to or extracted from a conditioned space to maintain the intended temperature conditions during a given period of time The energy need is calculated and cannot easily be measured. 13

15 pren O.A.:2012 (E) Draft energy need for humidification or dehumidification latent heat in the water vapour to be delivered to or extracted from a conditioned space by a technical building system to maintain a specified minimum or maximum humidity within the space energy source source from which useful energy can be extracted or recovered either directly or by means of a conversion or transformation process Examples include oil or gas fields, coal mines, sun, forests etc energy use for lighting electrical energy input to a lighting system energy use for other services electrical energy input to appliances providing other services This refers to services other than heating, cooling, domestic hot water, ventilation and lighting energy use for space heating or cooling or domestic hot water energy input to the heating, cooling or hot water system to satisfy the energy need for heating, cooling (including dehumidification) or hot water respectively If the technical building system serves several purposes (e.g. heating and domestic hot water) it can be difficult to split the energy use into that used for each purpose. It can be indicated as a combined quantity (e.g. energy need for space heating and domestic hot water) energy use for ventilation electric energy input to a ventilation system for air transport and heat recovery (not including energy input for preheating the air) and energy input to the humidification systems to satisfy the need for humidification exported energy energy, expressed per energy carrier, delivered by the technical building systems through the system boundary and used outside the system boundary 1 2 It can be specified by generation types (e.g. CHP, photovoltaic, etc) in order to apply different weighting factors. Exported energy can be calculated or it can be measured gross calorific value quantity of heat released by a unit quantity of fuel, when it is burned completely with oxygen at a constant pressure equal to Pa, and when the products of combustion are returned to ambient temperature This quantity includes the latent heat of condensation of any water vapour contained in the fuel and of the water vapour formed by the combustion of any hydrogen contained in the fuel. According to ISO , the gross calorific value is preferred to the net calorific value. The net calorific value does not take account of the latent heat nearby the building site outside the assessment boundaries and outside the building site 14

16 Draft pren O.A.:2012 (E) Thermal energy, or electricity which is distributed through a specific network net delivered energy delivered energy minus exported energy, both expressed per energy carrier 1 2 A balance of the delivered and exported energy per energy carrier can be performed only if the same primary energy factors and/or CO 2 coefficients apply to the delivered and exported amounts of that energy carrier. The term "net" can also be applied to quantities derived from net delivered energy, e.g. primary energy or CO 2 emissions non-renewable energy energy taken from a source which is depleted by extraction (e.g. fossil fuels) non-renewable primary energy factor for a given energy carrier, non-renewable primary energy divided by delivered energy, where the nonrenewable energy is that required to supply one unit of delivered energy, taking account of the nonrenewable energy required for extraction, processing, storage, transport, generation, transformation, transmission, distribution, and any other operations necessary for delivery to the building in which the delivered energy will be used The non-renewable primary energy factor can be less than unity if renewable energy has been used primary energy energy that has not been subjected to any conversion or transformation process 1 2 Primary energy includes non-renewable energy and renewable energy. If both are taken into account it can be called total primary energy. For a building, it is the energy used to produce the energy delivered to the building. It is calculated from the delivered and exported amounts of energy carriers, using conversion factors renewable energy energy from a source that is not depleted by extraction, such as solar energy (thermal and photovoltaic), wind, water power, renewed biomass In ISO :2002, renewable resource is defined as "natural resource for which the ratio of the creation of the natural resource to the output of that resource from nature to the techno-sphere is equal to or greater than one" renewable energy produced on the building site energy produced by technical building systems directly connected to the building using renewable energy sources total primary energy factor for a given energy carrier, non-renewable and renewable primary energy divided by delivered energy, where the primary energy is that required to supply one unit of delivered energy, taking account of the energy required for extraction, processing, storage, transport, generation, transformation, transmission, distribution, and any other operations necessary for delivery to the building in which the delivered energy will be used The total primary energy factor always exceeds unity. 15

17 pren O.A.:2012 (E) Draft 3.5 Energy ratings and certification calculated energy rating energy rating based on calculations of the weighted net delivered energy used by a building for heating, cooling, ventilation, domestic hot water and lighting National bodies can decide whether other energy uses resulting from occupants' activities such as cooking, production, laundry, computer equipment, etc. are included or not. If included, standard input data needs to be provided for the various types of building and uses. Lighting is always included except (by decision of national bodies) for residential buildings confidence interval interval that has a high probability (e.g. 95 %) to include the actual value design energy rating energy rating with design data for the building and standard use data set It represents the calculated intrinsic annual energy use of a designed building under standardised conditions. This is particularly relevant to obtain a building permit at the design stage energy certificate certificate recognised by a Member State or by a legal person designated by it, which indicates the energy performance of a building or building unit, calculated according to a methodology adopted in accordance with Article 3 of DIRECTIVE 2010/31/EU The meaning of the terms certificate and "certification" in this standard differ from that in EN ISO/IEC 17000, Conformity assessment Vocabulary and general principles (ISO/IEC 17000:2004) energy certification procedures enabling production of an energy certificate energy class easy to understand metric (e.g. A to G) for indicating the energy performance of a building energy performance indicator energy rating divided by conditioned area 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 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 energy rating evaluation of the energy performance of a building based on the weighted sum of the calculated or measured use of energy carriers 16

18 Draft pren O.A.:2012 (E) measured energy indicator measured energy rating divided by conditioned area measured energy rating energy rating based on measured amounts of delivered and exported energy 1 2 The measured rating is the weighted sum of all energy carriers used by the building, as measured by meters or other means. It is a measure of the in-use performance of the building. This is particularly relevant to certification of actual energy performance. Also known as "operational rating" reference value standard legal or calculated value against which an energy indicator is compared standard energy indicator standard energy rating divided by conditioned area standard energy rating calculated energy rating using actual data for a building and a standard use data set 1 2 It represents the intrinsic annual energy use of a building under standardised conditions. This is particularly relevant to certification of standard energy performance. It can also be termed "asset energy rating" standard use data set standard input data for internal and external climates, use, and occupancy 1 2 This set can also include information on surroundings (such as shading or sheltering by adjacent buildings). Such data sets are defined at national level statistical tolerance interval interval determined from a random sample in such a way that one may have a specified level of confidence that the interval covers at least a specified proportion of the sampled population The confidence level in this context is the long-run proportion of intervals constructed in this manner that will include at least the specified proportion of the sampled population tailored energy rating calculated energy rating using actual data for a building and actual climate and occupancy data 3.6 Costs reasonable cost cost that is accepted by all parties to reach a given purpose 1 This cost or a method to assess this cost should be given at the national level. 17

19 pren O.A.:2012 (E) Draft 2 This cost strongly depends on the purpose of the effort. For example, the cost of a rating could be relatively large if it is to provide an official certificate to put the building on the market or for displaying the building performance to the public, but reduced if it is simply for statistical purpose reasonably possible can be achieved at a reasonable cost 3.7 Energy calculation building calculation model mathematical model of the building, used to calculate its energy use building heat transfer coefficient sum of transmission and ventilation heat transfer coefficients calculation period period of time over which the calculation is performed The calculation period can be divided into a number of calculation steps calculation step discrete time interval for the calculation of the energy needs and uses for heating, cooling, ventilation, lighting, humidification and dehumidification Possible discrete time intervals are one hour, one month, one heating and/or cooling season, one year, operating modes, and bins equivalent internal temperature constant minimum internal temperature, assumed for the calculation of the energy for heating, or maximum internal temperature, assumed for the calculation of the energy for cooling, leading approximately to the same average heat transfer as would apply with intermittent heating or cooling, and with inaccuracy of room temperature control external temperature temperature of external air 1 2 For transmission heat transfer calculations, the radiant temperature of the external environment is supposed equal to the external air temperature; long-wave transmission to the sky is calculated separately. The measurement of external air temperature is defined in EN ISO , Hygrothermal performance of buildings Calculation and presentation of climatic data Part 1: Monthly means of single meteorological elements (ISO ) gain utilisation factor factor reducing the total monthly or seasonal heat gains to obtain the resulting reduction of the energy need for heating heat balance ratio monthly or seasonal heat gains divided by the monthly or seasonal heat transfer 18

20 Draft pren O.A.:2012 (E) heat gains heat generated within or entering into the conditioned space from heat sources other than energy intentionally utilised for heating, cooling or domestic hot water preparation 1 2 These include internal heat gains and solar heat gains. Sinks that extract heat from the building, are included as gains, with a negative sign. In contrast with heat transfer, for a heat source (or sink) the difference between the temperature of the considered space and the temperature of the source is not the driving force for the heat flow. For summer conditions heat gains with a positive sign constitute extra heat load on the space heating or cooling season period of the year during which a significant amount of energy for heating or cooling is needed The season lengths are used to determine the operation period of technical systems heat transfer coefficient heat flow rate divided by temperature difference between two environments; specifically used for heat transfer coefficient by transmission or ventilation intermittent heating or cooling heating or cooling pattern where normal heating or cooling periods alternate with periods of reduced or no heating or cooling internal heat gains heat provided within the building by occupants (sensible metabolic heat) and by appliances such as lighting, domestic appliances, office equipment, etc., other than energy intentionally provided for heating, cooling or hot water preparation This includes recoverable system thermal losses, if the holistic approach for the calculation of the recovered system losses is chosen internal temperature arithmetic average of the air temperature and the mean radiant temperature at the centre of the occupied zone This is the approximate operative temperature according to EN ISO 7726, Ergonomics of the thermal environment Instruments for measuring physical quantities (ISO 7727:1998) loss utilisation factor factor reducing the total monthly heat transfer to obtain the resulting reduction of the energy need for cooling set-back temperature minimum internal temperature to be maintained during reduced heating periods, or maximum internal temperature to be maintained during reduced cooling periods set-point temperature of a conditioned zone internal (minimum intended) temperature, as fixed by the control system in normal heating mode, or internal (maximum intended) temperature, as fixed by the control system in normal cooling mode 19

21 pren O.A.:2012 (E) Draft solar heat gain heat provided by solar radiation entering, directly or indirectly (after absorption in building elements), into the building through windows, opaque walls and roofs, or passive solar devices such as sunspaces, transparent insulation and solar walls Active solar devices such as solar collectors are considered as part of the technical building system solar irradiation incident solar heat per area over a given period transmission heat transfer coefficient heat flow rate due to thermal transmission through the fabric of a building, divided by the difference between the environment temperatures on either side of the construction By convention, if the heat is transferred between a conditioned space and the external environment, the sign is positive if the heat flow is from the space to outside (heat loss) useful heat gains proportion of internal and solar heat gains that contribute to reducing the energy need for heating validated building data set data used as input to a building calculation model in which one or more input data have been adjusted on the basis of actual data so that the results from a calculation using the model do not significantly differ from the measured reality The quality of the validated data set is a balance between reasonable costs for gathering data and reasonable accuracy ventilation heat transfer coefficient heat flow rate due to air entering a conditioned space either by infiltration or ventilation, divided by the difference between the internal air temperature and the supply air temperature 4 Symbols, units, subscripts and abbreviations 1 2 The symbols, units and subscripts and the rules for application are adopted from CEN/TR 15615:2008 and correspond with the symbols, units and subscripts in EN 15603:2008. The set of EPBD standards introduces a large number of quantities and their associated symbols. To facilitate the use of these standards, a common set of symbols and subscripts have been defined, as given in Table 1 and Table 2. The symbols follow established standards on nomenclature such as EN ISO 7345 and introduce others that are common to the set of EPBD standards; in particular a set of subscripts to distinguish between different energy uses, different energy carriers, etc. The symbols given in Table 1 concern only 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. Tables 1 and 2 provide the main symbols and subscripts. Annex B (normative) provides a more rules for application (hierarchy) of subscripts. 20

22 Draft pren O.A.:2012 (E) Symbol Quantity Table 1 Symbols and units A area m² b temperature reduction factor - Unit C heat capacity J/K a) c specific heat capacity J/(kg K) a) c coefficient d) various d thickness m D diameter m E energy in general e) kg, m 3, (kw h), J a) b) EP energy performance indicator J/(m 2 a), kg/(m 2 a), /(m 2 a) a) c) f factor (e.g. primary energy factor, policy factor, ) d) H heat transfer coefficient W/K H calorific value MJ/kg h surface coefficient of heat transfer W/(m² K) I solar irradiance W/m 2 k coefficient d) K CO2 emission coefficient kg/j; g/(kw h) L length m m mass (e.g. quantity of CO 2 emissions) kg n air exchange rate 1/h N number of items (integer only) O occupancy persons p pressure Pa P power in general including electrical power W Q quantity of heat J, (kw h) a) q volumetric airflow rate m 3 /s q heat flow density W/m² R thermal resistance m² K/W RER renewable energy ratio T thermodynamic temperature K t time, period of time s a) U thermal transmittance W/(m² K) V volume m³ W (electrical) auxiliary energy (kw h), J a) x relative humidity % X volume fraction % X, Y any property, system, Δ delta (difference) prefix to be combined with symbols various efficiency factor - ϑ Celsius temperature C (continued) 21

23 pren O.A.:2012 (E) Draft Table 1 (end) a) b) linear thermal transmittance W/(m K) heat flow rate, thermal power W point thermal transmittance W/K density kg/m³ time constant s 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 (W h) instead of J. The unit depends on the type of energy carrier. c) The unit depends on the indicator chosen, see EN clause 5. d) Coefficients have dimensions; factors are dimensionless. e) Including primary energy and energy carriers; note that for heat the symbol Q and for auxiliary energy and work the symbol W is used. Table 2 Subscripts Subscript Term Subscript Term 0 base, reference mn mean (time or space) a a air nd need A other appliances a nepus not related to considered building services an annual ngen without generation aux auxiliary nrbl non-recoverable avg time-average nrby nearby B building nren non-renewable bin bin nrvd not recovered bm biomass ntdel net delivered C cooling a nused not used (in the same calculation step) calc calculated nut non-utilised CO2 CO 2 emission off off cr energy carrier oil oil ctr control on on CW cooling and DHW a out output day daily P primary energy dc district cooling per for a period of time del delivered pk peak dh district heat Pnren non-renewable primary energy dhum dehumidification a pol related to policy dis distribution pr produced distant distant Ptot total primary energy (continued) 22

24 Draft pren O.A.:2012 (E) Table 2 (end) DU dehumidification (system) pv solar electricity (photovoltaic) e external; envelope rbl recoverable el electricity rdel redelivered in a different calculation step em emission red reduced EPus all building services included in the energy performance assessment ren renewable energy est estimated rvd recovered exp exported seas seasonal f floor sens sensible gas gas set setpoint gen generation sf solid fuel gn gains sol solar grid from public network (grid) sp space h hourly st storage H heating a sys system HC heating and cooling a T thermal a HCW heating, cooling and DHW a t calculation step ht heat transfer tmp temporary HU humidification a tot total hum humidification (system) Tot total a HW heating and DHW a tr transmission heat transfer i,j,k indexes us use in input used used in the same calculation step int internal ut utilised L lighting a V ventilation a lat latent ve ventilation heat transfer lf liquid fuel W domestic hot water (DHW) a ls losses wd wood m monthly wk weekly max maximum X any considered building service meas measured Y any subsystem min minimum z building zone a type of energy use Tables 3 provides the abbreviations used in this standard. 23

25 pren O.A.:2012 (E) Draft Table 3 Abbreviations Abbreviation AHU CHP DHW ED EP EPBD ID OID PV RER Term air handling unit combined heat and power domestic hot water (system) external dimension energy performance Energy Performance of Buildings Directive internal dimension overall dimension photo-voltaic total renewable energy ratio 5 Framework of the assessment of energy performance of buildings 5.1 Routing This standard provides the modular and over-arching framework for the assessment of energy performance of buildings. This standard is the common basis for the calculated and measured energy performance and also for energy performance inspection, at whole building, at building units or building element level. Depending on the application, all or some of the other standards related to the energy performance of buildings that cover other parts of the modular structure are needed. For the assessment of the energy performance the following steps have to be followed: 1) Identification of the application (checking compliance, certificate, type of rating; see 5.2). 2) For overall energy performance assessment: a) Specification of the building category or the building unit category or categories (e.g. residential building, office building, combined building, consisting of office and restaurant parts,..) and the related standardised use patterns (see 7.2). b) Specification of the building services (e.g. heating, cooling, lighting,..) included in the energy performance (see 7.3). c) Specification of the assessment boundaries (see 7.4). d) Calculation or measurement of the energy balance at the assessment boundaries, conversion to primary energy or other metric (e.g. CO 2 emission) see 7.5. e) Aggregation to the energy performance and the renewable energy contribution (see 7.6). 1. For calculated overall energy performance (see the calculation routing in 8); 2. For calculated energy performance at building or system element level (see 7.7); 3. For measured overall energy rating (see 12). 24

26 Draft pren O.A.:2012 (E) 5.2 Types and uses of ratings This standard gives two principal options for energy rating of buildings: calculated energy rating; measured energy rating. The calculated energy rating includes the building services as specified in 7.3 and applies to assumed operating conditions. If the measured energy rating (see 12) is not corrected to cover the same building services and assumed conditions, these two types of rating cannot be compared. The calculated energy rating can be either: standard, based on standard climate, use, outdoor environment and occupant-related input data, as specified in this standard. This rating is called "design rating" when applied to a planned building; tailored, calculated with climate, occupancy, outdoor environment and occupant related data adapted to the actual building and the purpose of the calculation. The types of rating are summarised in Table 4. Type of rating Table 4 Types of ratings Name of rating Input data Use Climate Building Calculated (asset rating) Design Standard Standard Design Standard Standard Standard Actual Tailored Depending on purpose Actual Measured Operational Actual Actual Actual The assessment method of the measured energy rating is given in 12. National bodies determine: which type of rating applies for each building category and purpose of the energy performance assessment; under what conditions the design rating can be considered as or converted to a calculated energy rating for the actually realised building. Default choices are given in Table A1. 6 The over-arching reference modular structure The overarching reference modular structure is used to identify: all required parts of the assessment procedure and provide an overview; the modules covered by the standards and to support specifications given to standard writers of the modules; the connection between the modules (e.g: calculation, expression of the energy performance). The over-arching modular structure has four main areas as shown in Table 5: 25