EN 17423-2020 pdf download.Energy performance of buildings – Determination and reporting of Primary Energy Factors (PEF) and C02 emission coefficient – General Principles, Module M1-7.
5.1.1.3 Gross and Net calorific value
The PEF can be expressed based on gross or net calorific values.
5.1.1.4 In-use phase or Life Cycle Analysis (LCA)
The PEF may focus only on the in-use phase or take into account also the embedded energy used (LCA,
see 6.4.4) for example to manufacture wind turbines.
5.1.2 CO2 emission coefficient
LCA approach is used in EN 15978 (Sustainability of construction works —Assessment of environmental performance of buildings — Calculation method) for the assessment of environmental impacts of buildings (including climate change) during life cycle of buildings (including operational energy use of buildings).
In EN 15978 and EN 15804 the LCA approach with GWP calculation rules have been aligned with
EN ISO 14067 (Carbon Footprint of Products) and the European Commission Product Environmental
Footprint (PEP) calculation rules applying the GWP 100 characterisation factors for the GWP calculations.
It is important that approaches in standards (and in regulations) are aligned in the construction sector, when they both are using the LCA approach for CO2 emissions (GWP) In order to direct the performance of buildings into the same direction, i.e. to mitigate climate change.
This document does not provide any GWP calculation rules but offers a standard template that helps reporting the main methodological choices.
The CO2 emission coefficient can also include the equivalent emission of other greenhouse gases (e.g. methane, N20, etc.). To be more precise, it should be specified by adding “equivalent (e.g. CO2 eq).
The emission factors shall be coherent with the choice of refernng to gross or net caloritic value. In line with EN ISO 52000-1, in this document the CO2 emission coefficients are applied to the energy delivered to the building or exported through the assessment boundary.
For the energy produced on-site and which can he exported, EN ISO 52000-1:20 17, 9.6.6 allows for either
a CO2 emission coefficient representing the resources avoided by the external grid or a CO2 emission
coefficient representing the resources used for producing the energy. Subclause 6.3.4 defines both
options.
2 emission coefficient for an exported energy carrier cr
Energy that is produced on-site can be exported. As for PEF calculation, ISO 52000-1 allows for either a CO2 emission coefficient representing the resources avoided by the external grid or a CO2 emission coefficient representing the resources used for producing the energy.
5.1.3 Assessment boundary
To start the determination and reporting of PEF and CO2 emission coefficient the perimeter of the assessment shall be set. It shall be clearly stated where the specific technical energy system ends (e.g. inside” — see hereafter) and where the assessment of the PEF and CO2 emission coefficient starts (“outside — see hereafter).
The assessment boundary is the boundary where the delivered and exported energy are measured or calculated to assess the building energy performance. In EN ISO 52000-1, the assessment boundary delimitates two systems:
— inside” the assessment boundary where the energy losses and auxiliary energy are taken into account explicitly as energy amounts. However in EN ISO 52000-1 CO2 emissions are not explicitly taken into account inside the assessment boundary. Therefore, the CO2 emissions factors of combustible energy vectors include the CO2 emissions of a perfect combustion process. The real efficiency is calculated inside the assessment boundary.
— outside the assessment boundary where the energy losses and auxiliary energy necessary to deliver one unit of the energy carrier to the building are taken into account in the PEFs per energy carrier. The PEF of delivered energy carriers shall only take into account losses and auxiliary related to the energy carrier. Otherwise the PEF and CO2 emission coefficient could not be applied in a coherent way to all buildings.
Therefore, the placement of the assessment boundary is important to clearly define what to take into account In the PEF and the CO2 emission coefficient. Examples on possible placements of the assessment boundary are provided in Annex B.
NOTE In EN ISO 52000-1:2017,9.5.1. the assessment boundary is defined as the output of active solar, wind or water energy systems. By convention, no primary energy losses are counted beyond this boundary for the upstream energy flow.
5.1.4 Origin of dehvered energies
The delivered energies are classified according to the following source perimeters:
— on-site,
— nearby,
— distant.
Refer to EN ISO 52000-1:2017, 9.5.1 for a complete description of the origin of delivered energies.EN 17423-2020 pdf download.