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Abstract(s)
Apesar do ritmo elevado de construção nova, o parque edificado português, em particular o residencial está genericamente envelhecido. Dos edifícios existentes em 2001, 80% eram anteriores a 1990, sendo 21% da década de 70, quando a construção não contemplava a otimização energética dos edifícios. Para manter o conforto térmico dentro destas habitações é necessário aumentar o seu consumo energético. Atualmente os edifícios são responsáveis por 40% do consumo energético mundial, sendo que a energia gasta em climatização é em grande parte perdida devido ao mau isolamento dos edifícios. Dado o imperativo de reduzir o consumo energético, estabelecido pelo Regulamento das Características de Comportamento Térmico dos Edifícios (RCCTE), tem havido uma aposta na reabilitação do edificado.
É neste contexto que surge a motivação para o desenvolvimento de um produto têxtil técnico para aplicação como revestimento de paredes na remodelação/ reabilitação de edifícios, que conjugue a função decorativa com a função técnica de isolamento térmico, permitindo aumentar a eficiência energética sem necessidade de alterações estruturais do edifício.
O objetivo deste trabalho é assim o desenvolvimento de uma estrutura compósita/ multicamada para revestimento de paredes interiores, que permita colmatar as deficiências existentes no que se refere ao isolamento térmico.
A metodologia de investigação consistiu em realizar a pesquisa bibliográfica de materiais convencionais e não convencionais utilizados no isolamento térmico de edifícios, assim como matérias utilizados no revestimento de paredes. Com base nesta pesquisa definiram-se os requisitos técnicos da estrutura.
Foram desenvolvidas várias estruturas têxteis, resultantes da conjugação de diferentes materiais têxteis e não têxteis de elevada performance térmica, nomeadamente da Fibra ? (resíduo de fibras inorgânicas não têxteis usadas no isolamento convencional de edifícios), e de diferentes processos, tendo sido avaliado o seu desempenho.
Foram seguidas duas abordagens técnicas. A primeira consistiu no revestimento de uma tela 100% Poliéster com pastas à base de Fibra ? e posterior laminagem com um não-tecido. Os resultados de resistência térmica desta amostra (0,065 m2.K/W) são baixos relativamente ao objetivo proposto para este estudo (0,500 m2.K/W), pelo que esta abordagem foi abandonada.
A segunda abordagem consistiu no desenvolvimento de um não-tecido Fibra ?/Poliéster. Ao longo deste desenvolvimento verificou-se o incremento da resistência térmica e homogeneidade das estruturas desenvolvidas.
Desta investigação concluiu-se que a estrutura obtida apresenta características de isolamento térmico que não se verifica em outros materiais para revestimento de paredes, e que este efeito está diretamente relacionado com a espessura da estrutura e com a sua composição. A investigação provou ainda a viabilidade da produção de não-tecidos com base na conjugação da Fibra ? com fibras têxteis (poliéster) e que a primeira aumenta a resistência térmica até uma proporção de 70% na mistura, a partir da qual o não-tecido deixa de ter coesão e o efeito de aumento da resistência térmica sofre uma inversão.
O valor de resistência térmica (Rct) do protótipo final foi 0,161 m2.K/W para uma espessura de 3,41 mm. Este valor ficou aquém do pretendido, mas a espessura obtida é inferior ao valor máximo esperado (10 mm), pelo que em futuras otimizações do não-tecido se poderá aumentar a sua espessura e com isso aproximar o valor de Rct da estrutura final do valor requerido, uma vez que existe uma relação direta entre estes parâmetros.
Despite the high rate of new construction, the Portuguese buildings, mainly the residential ones, are generally aged. From the existing buildings in 2001, 80% were prior to 1990, witch 21% were from the seventies, when construction did not comprise energy optimization. To maintain thermal comfort inside these buildings is necessary to increase the energy spent. Currently buildings are responsible for 40% of global energy consumption and the energy consumed in air conditioning is mostly lost due to poor buildings insulations. Given the imperative to reduce energy consumption established by the “Regulamento das Características de Comportamento Térmico dos Edifícios (RCCTE)”, there has been a focus on building rehabilitation. It is in this context that the ambition for the development of an innovative technical textile product for application as wall covering in the rebuilding/restoration of buildings arises. Combining the decorative function with thermal insulation technical function, it will allow increasing energy efficiency without the need for structural changes in the building. The key objective of this work is to develop a composite/ multilayer structure for wall covering in interior building spaces that will allow overcoming shortcomings regarding thermal insulation. The research methodology used consisted of bibliographic research regarding conventional and unconventional materials used for buildings thermal insulation, as well as materials used in wall covering. Based on this research the technical requirements of the structure were defined. Several textile structures have been developed, resulting from the combination of different textiles and non-textile materials with high thermal performance, namely ? Fiber (waste from inorganic fibers used in conventional building insulation) using different technical approaches. The performance of the structures was evaluated. The first technological approach used consisted in processing ? Fiber into a coating over a 100% polyester woven fabric, which was afterwards laminated with a 100% polyester non-woven. The thermal resistance value obtained was low (0,065 m2.K/W) comparing with the intended (0,500 m2.K/W), so this approach was abandoned. The other technique used was the development of a non-woven ? Fiber/ polyester. Throughout the development there was an increase in thermal resistance and homogeneity of the developed structures. This research permitted to conclude that the multilayer structure obtained has thermal insulation characteristics which were not observed in other materials for interior wall coverings, and that this effect is directly related to the thickness of the structure and its composition. The research also proved the feasibility of producing non-woven based on the blend of ? Fiber with textile fibers (polyester) and that the ? Fiber increase the thermal resistance up to a proportion of 70% in the mixture, from which the non-woven no longer has cohesion and the thermal resistance effect decreases. The final prototype (industrialized) thermal resistance value was 0,161 m2.K/W, with 3,41mm thickness. This value fell short of the desired, but as the thickness obtained is lower than the maximum expected value, (10 mm), whereby in future optimization of the non-woven it is possible to increase its thickness and thus approximate the thermal resistance value of the industrial prototype to the desired, since there is a direct connection between these parameters.
Despite the high rate of new construction, the Portuguese buildings, mainly the residential ones, are generally aged. From the existing buildings in 2001, 80% were prior to 1990, witch 21% were from the seventies, when construction did not comprise energy optimization. To maintain thermal comfort inside these buildings is necessary to increase the energy spent. Currently buildings are responsible for 40% of global energy consumption and the energy consumed in air conditioning is mostly lost due to poor buildings insulations. Given the imperative to reduce energy consumption established by the “Regulamento das Características de Comportamento Térmico dos Edifícios (RCCTE)”, there has been a focus on building rehabilitation. It is in this context that the ambition for the development of an innovative technical textile product for application as wall covering in the rebuilding/restoration of buildings arises. Combining the decorative function with thermal insulation technical function, it will allow increasing energy efficiency without the need for structural changes in the building. The key objective of this work is to develop a composite/ multilayer structure for wall covering in interior building spaces that will allow overcoming shortcomings regarding thermal insulation. The research methodology used consisted of bibliographic research regarding conventional and unconventional materials used for buildings thermal insulation, as well as materials used in wall covering. Based on this research the technical requirements of the structure were defined. Several textile structures have been developed, resulting from the combination of different textiles and non-textile materials with high thermal performance, namely ? Fiber (waste from inorganic fibers used in conventional building insulation) using different technical approaches. The performance of the structures was evaluated. The first technological approach used consisted in processing ? Fiber into a coating over a 100% polyester woven fabric, which was afterwards laminated with a 100% polyester non-woven. The thermal resistance value obtained was low (0,065 m2.K/W) comparing with the intended (0,500 m2.K/W), so this approach was abandoned. The other technique used was the development of a non-woven ? Fiber/ polyester. Throughout the development there was an increase in thermal resistance and homogeneity of the developed structures. This research permitted to conclude that the multilayer structure obtained has thermal insulation characteristics which were not observed in other materials for interior wall coverings, and that this effect is directly related to the thickness of the structure and its composition. The research also proved the feasibility of producing non-woven based on the blend of ? Fiber with textile fibers (polyester) and that the ? Fiber increase the thermal resistance up to a proportion of 70% in the mixture, from which the non-woven no longer has cohesion and the thermal resistance effect decreases. The final prototype (industrialized) thermal resistance value was 0,161 m2.K/W, with 3,41mm thickness. This value fell short of the desired, but as the thickness obtained is lower than the maximum expected value, (10 mm), whereby in future optimization of the non-woven it is possible to increase its thickness and thus approximate the thermal resistance value of the industrial prototype to the desired, since there is a direct connection between these parameters.
Description
Keywords
Condutibilidade Térmica Estrutura Têxtil Multicamada Isolamento Térmico Não-Tecidos Reabilitação de Edifícios. Resistência Térmica Revestimento de Paredes