Bio-based insulation materials and their hygrothermal performance in a building envelope system (ETICS)

Bio-based insulation materials (such as wood or hemp) are emerging as a promising alternative in building envelope applications, aiming at improving in-use energy efficiency. When compared to common insulation materials (rock and glass wool or petrol-based foams) bio-based materials present the adva...

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Detalles Bibliográficos
Autores: Palumbo, Mariana, Lacasta Palacio, Ana María|||0000-0002-9060-6043, Haurie Ibarra, Laia|||0000-0002-0732-8928, Giraldo Forero, María del Pilar|||0000-0002-3254-9212, Correal Modol, Eduard
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/126064
Acceso en línea:https://hdl.handle.net/2117/126064
https://dx.doi.org/10.1016/j.enbuild.2018.06.042
Access Level:acceso abierto
Palabra clave:Thermal analysis
Insulating materials
Insulation (Heat)
Hygrometry
Bio-based materials
Bio aggregates
Thermal insulation
Hygrothermal performance
Corn pith
Construction
Anàlisi tèrmica
Aïlladors
Aïllament tèrmic
Higrometria
Àrees temàtiques de la UPC::Edificació::Materials de construcció
Descripción
Sumario:Bio-based insulation materials (such as wood or hemp) are emerging as a promising alternative in building envelope applications, aiming at improving in-use energy efficiency. When compared to common insulation materials (rock and glass wool or petrol-based foams) bio-based materials present the advantage of being renewable, with a low embodied energy and CO2 neutral or negative. Moreover, these materials have a distinct hygrothermal performance, as the sorption/desorption of water vapour in their porous structure, in dynamic equilibrium with their surrounding environment, constantly modifies their hygric and thermal properties while causing energy transfers itself. In this paper, the hygrothermal performance of two different bio-based materials in outdoor conditions is evaluated. The first is an innovative light-weight composite made from corn pith and alginate. The second a commercially available wood insulator. The materials are tested alone and as components of external thermal insulation systems (ETICS) and compared to a conventional polystyrene foam. The results show how the sorption process influence the hygrothermal performance of the materials when the surrounding conditions are modified. When subjected to cyclic changes in temperature and relative humidity, the bio-based materials tested show a lower temperature variation than polystyrene. This is in part due to their lower thermal diffusivity, but also to the water absorption and desorption mechanisms occurring within the materials, which were measured by the change in mass of the materials during the tests. The differences in the thermal performance were more noticeable when the insulation materials were tested alone than when these were tested as a part of an ETIC System.