General comment Data quality:
The data Quality Levels, according to Table E.1 of EN 15804 +A2, Annex E, are:
Geographical representativeness: Very good: the production location of the blocks lies within the region for which the relevant Ecoinvent (version 3.8) environmental records have been selected.
Time representativeness: Very good: the data relating to the manufacturing of the blocks, and the data relating to the background processes for environmental impacts are recent (<2 years). The LCA dataset for the cement is from 2021 and is of the specific cement used in production.
Technical representativeness: Very good: the processes and energies used in the process have been modelled exactly as described by Mannok Aircrete blocks and are based directly on the production data supplied by Mannok for the Aircrete block production.
Allocation:
The measurement of environmental impacts in this EPD uses the LCIA methodologies recommended for PEF 3.1. In this EPD, the waste processes are allocated in the relevant module. In the case of the use of secondary materials or energy recovered from secondary fuels, the system boundary between the system under study and the previous system (providing the secondary materials) is set where outputs of the previous system, e.g. materials, products, building elements or energy, reach the end-of-waste state. The modularity and the polluter payer principles have been followed.
Allocation of energies such as diesel, propane and electricity types and amounts to the various manufacturing processes has been provided by the manufacturer, along with production waste and direct emissions; allocation of impacts to the products is based on the product composition mass.
Cut-off criteria:
All relevant inputs and outputs - like emissions, energy and materials - have been taken into account in this LCA, and in accordance with EN15804+A2:2019. The study covers at least 95% of the materials and energy per module and at least 99% of the total use of materials and energy of each unit process. Long term emissions have been excluded from the study.
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