Les toitures végétalisées ont des répercussions très positives sur la performance énergétique des bâtiments. L’objectif est d’évaluer l’incidence des toitures végétalisées sur la performance énergétique des bâtiments à travers des moyens numériques et expérimentaux. La modélisation du comportement thermo-hydrique des toitures végétalisées permet de quantifier ces effets et contribue à promouvoir cette technique.Cette thématique requiert en premier lieu des compétences en énergétique du bâtiment et de modélisation thermique dynamique, si l’on souhaite établir un modèle représentatif du comportement thermo-hydrique d’un composant de toiture végétalisée. Afin de développer ces différents aspects, un travail préliminaire qui consiste en une étude bibliographique approfondie portant sur les modèles proposés dans la littérature a été entrepris. Sur la base de cette étude bibliographique, un modèle couplé de transfert de chaleur et d’humidité a été développé. Ce modèle est basé sur l’établissement des équations de bilan énergétique sur la surface du feuillage et la surface du sol. Afin d’affiner le modèle développé et d’obtenir de meilleurs résultats numériques, diverses caractérisations expérimentales des matériaux qui entrent dans la composition de la toiture végétalisée ont été effectuées. Une plateforme expérimentale (Climabat, échelle 1/10) a été conçue sur le site de l’Université de La Rochelle dans le but de mesurer l’incidence des toitures végétalisées sur les bâtiments et fournir des données permettant de calibrer et de vérifier le modèle développé. Des comparaisons ont été entreprises entre toiture végétalisée et toiture classique, une différence de température de surface extérieure de 30°C a été notée pendant la période d’été. Les résultats des simulations montrent aussi que la végétalisation des toitures de bâtiment améliore non seulement les conditions de son confort thermique mais aussi sa performance énergétique. Des campagnes de mesures ont été également effectuées sur des bâtiments réels équipés avec des toitures végétalisées. La validation expérimentale du modèle développé a été ensuite entreprise à deux échelles, l’une à échelle réduite (maquette échelle 1:10) sur des bancs d’essais sur le site de l’Université de La Rochelle et une à échelle réelle, sur des pavillons BBC existants où différentes typologies de toitures végétalisées ont été instrumentées. Une fois le modèle développé et sa pertinence vérifiée par comparaison à des mesures expérimentales, il a été couplé à un code de simulation thermique dynamique des bâtiments (TRNSYS). Cela a permis de prédire la performance énergétique et le calcul des besoins de chauffage et de climatisation des bâtiments équipés d'une toiture végétalisée. Les résultats de simulations ont montré que la présence d'une toiture végétalisée permet une réduction des besoins des bâtiments et protège la membrane d’étanchéité de la toiture des températures extrêmes et des grandes fluctuations de température. De plus, il a été constaté que l'effet des toitures végétalisées sur la réduction de la température de l'air intérieur est plus important en été. Aussi, il a été constaté que les besoins de climatisation et de chauffage dépendent fortement du niveau d'isolation de la toiture. Enfin, les simulations réalisées pour différents climats ont montré que la toiture végétalisée est bénéfique pour le climat des pays européens. / Green roofs have a positive effect on the energy performance of buildings, providing a cooling effect in summer, along with a more efficient harnessing of the solar radiation, due to the reflective properties of the foliage. To assess these effects, a thermodynamic model was developed as well as the thermo-physical properties of the green roof components were characterized.The proposed model is based on energy balance equations expressed for foliage and soil media. The influence of the mass transfer on the thermal properties, and evapotranspiration were taken into account. Then, the water balance equation was added into the developed model and numerical simulations were performed. In order to evaluate the temperatures evolution at foliage and soil ground levels.Three of the main physical properties of green roofs were experimentally investigated to determine some of the green roofs’ modeling key parameters. First, the thermo-physical properties of green roofs were characterized by correlating the thermal conductivity of the substrate with the water content for different substrates and maximum water capacities. Next, the moisture storage was characterized using the dynamic vapor sorption technique. Third, themicro-structural properties of green roof substrate were characterized using mercury intrusion porosimetry. In addition to these characterizations, the evapotranspiration term, which is very important in the water balance, was measured.The model was experimentally validated according to a green roof platform (scale 1:10) constructed on the site of the University of La Rochelle. Measurements have also been conducted in a full scale building equipped with green roofs. Once the proposed model validated, it has been coupled to a building thermal code (TRNSYS) to evaluate the impact of green roofs on the energy performance of buildings.The results show that the effect of mass transfer in the subtract was very effective in reducing the model errors. Comparisons were undertaken with a roof slab concrete model; a significant difference in temperature (up to 30 °C) between the outer surfaces of the two roofs was noticed in summer. The heat flux through the roof was also evaluated. The roof passive cooling effect was three times more efficient with the green roof. In the winter, the green roof reduced roof heat losses during cold days; however, it increased these losses during sunny days. With a green roof, the summer indoor air temperature was decreased by 2 °C, and the annual energy demand was reduced by 6% for an oceanic climate such as that of La Rochelle. Finally, the simulations performed for different climates suggest that green roofs are thermally beneficial for hot, temperate, and cold European climates.

O uso telhados verdes oferece benefícios como: moderação dos valores da temperatura no interior de edificações e contenção temporária da água de chuva, limpeza de poluentes atmosféricos, além de favorecer aspectos ecológicos. Poucos estudos científicos foram realizados no sentido de adaptar as técnicas contemporâneas e a indicação de espécies apropriadas ao sistema de telhado verde extensivo, originadas de regiões de clima temperado para as condições dos climas tropicais. O objetivo desta pesquisa foi identificar espécies com potencial de uso em telhado verde em sistema extensivo, quantificando a reação das plantas à variação de diferentes profundidades de substrato, em situações limitadas de manutenção, no aspecto de irrigação e nutrição do solo. Procurou-se também registrar o comportamento térmico do solo, a fim de verificar a influência da vegetação no aquecimento da parte inferior do solo em relação a distintas profundidades de substrato. Os vegetais foram plantados em setembro de 2009 aplicados em 27 plataformas de teste. Foram cultivadas três espécies de plantas das famílias Fabaceae (Arachis repens Handro), Poaceae (Paspalum notatum Flügge) e Ruscacea (Ophiopogon japonicus (L.F. Ker Gawl)), sob três tratamentos de profundidades de substrato, 0.05, 0.075 e 0.10 m. Quantificou-se mensalmente a porcentagem de cobertura vegetal, crescimento vertical e de sobrevivência, com encerramento ao final de um ciclo anual. O comportamento térmico dos solos nos diferentes tratamentos foi registrado automaticamente por meio de sensores. Os resultados indicaram a espécie Ophiopogon japonicus, em solos de 0.10 m, como a que apresentou o melhor desempenho entre as três examinadas, seguida por Paspalum notatum. Todas as espécies cultivadas em solos de 0.10 m apresentaram resultados satisfatórios quanto a cobertura do solo, crescimento vertical e sobrevivência, em relação ao cultivo em profundidades menores de substrato. O cultivo em menor profundidade de solo (0.05 m) revelou baixo valor de sobrevivência para todas as espécies durante o período de poucas chuvas. O crescimento vertical foi satisfatório para todas as espécies analisadas, dispensando manutenção com poda regular. Os resultados de comportamento térmico indicaram melhor desempenho de solos à profundidade de 0.10 m, independente do tipo de planta cultivado. Concluiu-se que solos de menor espessura são mais dependentes de cobertura vegetal para minimizar seu aquecimento e que os solos de maior espessura o fazem com menor dependência da vegetação. O melhor desempenho térmico foi observado em solos de 0.10 m, em relação às profundidades menores, embora não variasse seu comportamento térmico significativamente com o cultivo das três diferentes espécies de plantas, referente aos valores de cobertura atingidos neste experimento. / The uses of green roofs provide benefits such as moderation of the temperature inside buildings, temporary containment of rainwater, cleaning of air pollutants, in addition to promoting ecological aspects. Few scientific studies have been conducted to adapt contemporary techniques and indication of appropriate species for extensive green roof system, originated from temperate regions to the conditions of tropical climates. The objective of this research was to identify species with potential for use in green roof in the extensive system, quantifying the response of plants to variation of different depths of substrate, in limited situations of maintenance in respect of irrigation and soil nutrition. Was searched register the thermal behavior of soil in order to determine the influence of vegetation on the warming of the lower soil depths for different substrates. The plants were planted in september 2009, applied in 27 platforms. There were three species of cultivated plants of the families Fabaceae (Arachis repens Handro), Poaceae (Paspalum notatum Flügge) and Ruscacea (Ophiopogon japonicus (L.F.) Ker Gawl) under three treatments of substrate depths, 0.05, 0.075 and 0.10 m. Was quantified the percentage of monthly vegetation cover, vertical growth and survival, with closing at the end of an annual cycle. The thermal behavior of soils under different treatments was recorded using sensors. The results indicated that Ophiopogon japonicus in 0.10 m soils, showed the best performance among the three examined. All species grown in 0.10 m of soils had been satisfactory results of soil cover, vertical growth and survival in relation to culture in shallower substrate. The species Arachis repens showed the highest sensitivity to the depth and water stress during the autumn and winter, requiring more necessity of maintenance. Cultivation in shallower soil (0.05 m) showed low survival value for all species during the short rains. The vertical growth was satisfactory for all species analyzed, of which the greatest height reached was Ophiopogon japonicus without requiring regular maintenance pruning. The results indicated better performance thermal behavior of soil to a depth of 0.10 m, regardless of the type of plant grown. It was concluded that soils of lesser thickness are dependent on vegetation cover to minimize your heating, and the soils with more thickness are less dependence on the vegetation. The best thermal performance was observed in soils of 0.10 m compared to shallower depths, but did not vary significantly its thermal behavior with the cultivation of three different species of plants, referring to amounts of coverage achieved in this experiment.

The purpose of this study is to determine if Low Impact Development (LID) can effectively mitigate flooding under projected climate scenarios. LID relies on runoff management measures that seek to control rainwater volume at the source by reducing imperviousness and retaining, infiltrating and reusing rainwater. An event-driven hydrologic/hydraulic model was developed to simulate how climate change, land use and LID scenarios may affect runoff response in the Bowker Creek watershed, a 10km2 urbanized catchment located in the area of greater Victoria, British Columbia, Canada. The first part of the study examined flood impacts for the 2050s (2040-2069) following the A2 emissions scenario. For the 24-hour, 25-year local design storm, results show that projected changes in rainfall intensity may increase flood extents by 21% to 50%. When combined with continued urbanization flood extents may increase by 50% to 72%. The second part of the study identified potential locations for three LID treatments (green roofs, rain gardens and top soil amendments) and simulated their effect on peak in-stream flow rates and flood volumes. Results indicate that full implementation of modeled LID treatments can alleviate the additional flooding that is associated with the median climate change projection for the 5-year, 10-year and 25-year rainfall events. For the projected 100-year event, the volume of overland flood flows is expected to increase by 1%. This compares favourably to the estimated 29% increase without LID. In term of individual performance, rain gardens had the greatest hydrologic effect during more frequent rainfall events; green roofs had minimal effect on runoff for all modelled events; and top soil amendments had the greatest effect during the heaviest rainfall events. The cumulative performance of LID practices depends on several variables including design specifications, level of implementation, location and site conditions. Antecedent soil moisture has a considerable influence on LID performance. The dynamic nature of soil moisture means that at times LID could meet the mitigation target and at other times it may only partially satisfy it. Future research should run continuous simulations using an appropriately long rainfall record to establish the probabilities of meeting performance requirements. In general, simulations suggest that if future heavy rainfall events follow the median climate change projection, then LID can be used to maintain or reduce flood hazard for rainfall events up to the 25-year return period. This study demonstrates that in a smaller urban watershed, LID can play an important role in reducing the flood impacts associated with climate change. / Graduate

Cette recherche s’intéresse à la valeur d’usage du toit vert dans l’arrondissement du Plateau Mont-Royal, de la Ville de Montréal. Spécifiquement, elle s’intéresse à l’état problématique qu’est l’étalement urbain en tentant l’estimation de la valeur d’usage du toit vert, de la cour arrière et du balcon-terrasse soutenue par le dispositif argumentaire immobilier propre à chacun des aménagements. L’étalement urbain est la source de graves problèmes et la résorption de ses effets néfastes est devenue une priorité dans l’aménagement du territoire. L’une des principales raisons sousjacentes à l’exode urbain est la valeur d’usage accordée à la parcelle extérieure qu’offre l’habitat unifamilial pavillonnaire. Dans cette situation, la question est de savoir si l’insertion d’espaces verts privés en milieu urbain peut participer à la résorption de l’exode urbain. Or, dans l’agglomération, le sol manque. Le toit vert privé apparaît comme une alternative astucieuse, bien que limitée, au terrain entourant la maison. Reste à savoir si les gens le valorisent tel un espace vert privé d’extrême proximité, à même le sol. À la lueur de l’analyse, il advient que le toit vert ne présente pas de valeur d’usage comparable à celle de la cour arrière dans le contexte observé, précisément parce que leurs publics cibles s’opposent d’emblée. En revanche, le balcon-terrasse et le toit vert semblent être, en fonction des données construites, des aménagements à valeur d’usage comparable. / This research focuses on the use-value of green roofs in Plateau Mont-Royal, a borough in the city of Montreal. It focuses on the problematic state of urban sprawl by trying to estimate the use-value of the green roof, backyard and terrace, supported by the real estate argumentation of each facilities. Urban sprawl is the source of serious problems and the absorption of its harmful effects has become a priority in urban planning. One of the main reasons underlying the prevalent urban exodus is the value given to the use of exterior land offered by the single-family suburban habitat. In this situation, the main interest is to know if the inclusion of private open spaces in urban areas can participate in the resumption of the urban exodus. Because lack of soil in the city is an obstacle, the private green roof appears as a smart, although limited, alternative for the land surrounding a house. But this option is only relevant if people value these alternative private open spaces as they value the ground spaces. After analysis, it happens that the green roof has no use-value comparable to the backyard in the observed context, particularly because their respective public opposes outright. On the other hand, based on construction data, the terrace and green roof seem to have a comparable use-value.

Visando minimizar os impactos causados pelas ações antrópicas sobre o meio ambiente, mais especificamente sobre os recursos hídricos, torna-se imprescindível a busca por fontes alternativas para suprir as crescentes demandas de água para os mais diversos fins. Medidas como o reuso da água e a captação e aproveitamento de água das chuvas são fundamentais no contexto atual de busca por modelos sustentáveis de gestão dos recursos hídricos. No presente trabalho foi realizada extensa pesquisa bibliográfica sobre como o uso de telhados verdes pode contribuir para o uso racional da água potável e para a redução da ocorrência de enchentes. A área de estudo em questão foi Ilha Grande, localizada no litoral sul do Estado do Rio de Janeiro, uma Área de Preservação Permanente que, dentre outras Unidades de Conservação da Natureza, abriga o Parque Estadual de Ilha Grande. Para se analisar a viabilidade de implantação de um telhado verde na região, mais especificamente na Vila Dois Rios (23o11S, 44o12W), foi realizado o levantamento das séries históricas de chuvas da última década na região. Espécies vegetais compatíveis para uso em telhado verde foram encontradas na Ilha e, além disso, foram identificadas as premissas construtivas e operacionais relevantes. Para promover a conscientização dos visitantes e moradores locais foi elaborada uma cartilha informativa ilustrativa. Por fim, concluiu-se que existe a viabilidade de implantação de um telhado verde para captação e aproveitamento das águas das chuvas em Ilha Grande.

O crescimento populacional aliado à migração tem aumentado a pressão sobre o uso do solo urbano perpetuando sucessivos problemas de assentamentos informais e saneamento ambiental nos grandes centros. Esta situação se agrava ainda mais em épocas de chuvas intensas devido à ocorrência de enchentes. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq/CTHIDRO/CTAGRO), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este projeto utilizou uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento), com o objetivo de verificar aspectos construtivos, possíveis espécies com potencial de geração de renda, custos, efeitos no retardo do escoamento superficial das águas pluviais e outros benefícios associados a questões climáticas locais e de conforto do ambiente interno. Os resultados gerados demonstraram, entre outros, o estabelecimento de metodologia para implantação dos telhados verdes em habitações populares, o valor dos custos e resultados preliminares de espécies com potencial para geração de renda. Ainda, a implantação dos telhados verdes demonstrou ser promissora no controle do escoamento superficial, na aplicação do sistema de irrigação. Na simulação das chuvas, observou-se uma retenção de até 56% do volume precipitado. Observou-se o retardo da ocorrência do pico de até 8 minutos no telhado vegetado em relação ao telhado testemunho (convencional telhas fibrocimento). Foi observada a eficiência tanto no comportamento térmico interno como também no externo, uma redução da amplitude térmica interna em dia característico de verão (35,9 C), sendo capaz de r eduzir a temperatura interna em cerca de 2,0 C nos períodos mais quentes do dia e cerca de 4,0 C no ambiente externo em comparação com o telhado-testemunha (sem plantio), com potencial de modificação do microclima local. / The population growth and migration has increased the pressure on land use and urban occupation, increasing the problems of informal occupation (urban settlements) and environmental sanitation in large cities. This is even worse when urban floods occur. This project is part of a set of citizenship and social inclusion integrated actions in Jacarepaguá low-land hydrographic region, involving the Community of Vila Cascatinha, Vargem Grande, Rio de Janeiro, Brazil, in order to propose new public policies for informal settlements. This study is part of HIDROCIDADES project (CNPq / CTHIDRO / CTAGRO), which focus on water conservation in the urban and peri-urban environment associated to citizenship, social inclusion and life quality improvements in large cities. This project applied an adapted technology for green roofs on social interest buildings (fiber-cement tiles), in order to verify constructive aspects, possible crops to with income raising potential, costs, the effects on surface flow control and other benefits, such as buildings thermal comfort improving, microclimate. Results, demonstrated, among others, the establishment of a methodology for implementing green roofs for social interest buildings, costs and preliminary crops. In addition, the establishment of the green roof showed effects on controlling surface runoff. During the application of the irrigation system for rainfall simulation it was observed up to 56% retention of the total precipitation. It was observed a delay up to 8 minutes to runoff peak when comparing to the flow over tiles roof. It was verified the external thermal behavior, reducing the internal temperature range of typical days in summer (35.9 C), being able to reduce internal temperature by 2.0 C durin g warmer periods of the day and about 4.0 C in the external environment, compared with the tiles roof, being efficient on the local microclimate modification.

Visando minimizar os impactos causados pelas ações antrópicas sobre o meio ambiente, mais especificamente sobre os recursos hídricos, torna-se imprescindível a busca por fontes alternativas para suprir as crescentes demandas de água para os mais diversos fins. Medidas como o reuso da água e a captação e aproveitamento de água das chuvas são fundamentais no contexto atual de busca por modelos sustentáveis de gestão dos recursos hídricos. No presente trabalho foi realizada extensa pesquisa bibliográfica sobre como o uso de telhados verdes pode contribuir para o uso racional da água potável e para a redução da ocorrência de enchentes. A área de estudo em questão foi Ilha Grande, localizada no litoral sul do Estado do Rio de Janeiro, uma Área de Preservação Permanente que, dentre outras Unidades de Conservação da Natureza, abriga o Parque Estadual de Ilha Grande. Para se analisar a viabilidade de implantação de um telhado verde na região, mais especificamente na Vila Dois Rios (23o11S, 44o12W), foi realizado o levantamento das séries históricas de chuvas da última década na região. Espécies vegetais compatíveis para uso em telhado verde foram encontradas na Ilha e, além disso, foram identificadas as premissas construtivas e operacionais relevantes. Para promover a conscientização dos visitantes e moradores locais foi elaborada uma cartilha informativa ilustrativa. Por fim, concluiu-se que existe a viabilidade de implantação de um telhado verde para captação e aproveitamento das águas das chuvas em Ilha Grande.

O crescimento populacional aliado à migração tem aumentado a pressão sobre o uso do solo urbano perpetuando sucessivos problemas de assentamentos informais e saneamento ambiental nos grandes centros. Esta situação se agrava ainda mais em épocas de chuvas intensas devido à ocorrência de enchentes. Este projeto faz parte de um conjunto de ações integradas de cidadania e inclusão social na região hidrográfica da baixada de Jacarepaguá, especificamente envolvendo a Comunidade da Vila Cascatinha, em Vargem Grande, a fim de gerar subsídios para políticas públicas em áreas de assentamentos informais, integrado ao projeto HIDROCIDADES (CNPq/CTHIDRO/CTAGRO), que visa a conservação da água em meios urbanos e periurbanos associado à cidadania, inclusão social e melhoria da qualidade de vida nas grandes cidades. Este projeto utilizou uma tecnologia adaptada dos telhados verdes para edificação popular (telhado de fibrocimento), com o objetivo de verificar aspectos construtivos, possíveis espécies com potencial de geração de renda, custos, efeitos no retardo do escoamento superficial das águas pluviais e outros benefícios associados a questões climáticas locais e de conforto do ambiente interno. Os resultados gerados demonstraram, entre outros, o estabelecimento de metodologia para implantação dos telhados verdes em habitações populares, o valor dos custos e resultados preliminares de espécies com potencial para geração de renda. Ainda, a implantação dos telhados verdes demonstrou ser promissora no controle do escoamento superficial, na aplicação do sistema de irrigação. Na simulação das chuvas, observou-se uma retenção de até 56% do volume precipitado. Observou-se o retardo da ocorrência do pico de até 8 minutos no telhado vegetado em relação ao telhado testemunho (convencional telhas fibrocimento). Foi observada a eficiência tanto no comportamento térmico interno como também no externo, uma redução da amplitude térmica interna em dia característico de verão (35,9 C), sendo capaz de r eduzir a temperatura interna em cerca de 2,0 C nos períodos mais quentes do dia e cerca de 4,0 C no ambiente externo em comparação com o telhado-testemunha (sem plantio), com potencial de modificação do microclima local. / The population growth and migration has increased the pressure on land use and urban occupation, increasing the problems of informal occupation (urban settlements) and environmental sanitation in large cities. This is even worse when urban floods occur. This project is part of a set of citizenship and social inclusion integrated actions in Jacarepaguá low-land hydrographic region, involving the Community of Vila Cascatinha, Vargem Grande, Rio de Janeiro, Brazil, in order to propose new public policies for informal settlements. This study is part of HIDROCIDADES project (CNPq / CTHIDRO / CTAGRO), which focus on water conservation in the urban and peri-urban environment associated to citizenship, social inclusion and life quality improvements in large cities. This project applied an adapted technology for green roofs on social interest buildings (fiber-cement tiles), in order to verify constructive aspects, possible crops to with income raising potential, costs, the effects on surface flow control and other benefits, such as buildings thermal comfort improving, microclimate. Results, demonstrated, among others, the establishment of a methodology for implementing green roofs for social interest buildings, costs and preliminary crops. In addition, the establishment of the green roof showed effects on controlling surface runoff. During the application of the irrigation system for rainfall simulation it was observed up to 56% retention of the total precipitation. It was observed a delay up to 8 minutes to runoff peak when comparing to the flow over tiles roof. It was verified the external thermal behavior, reducing the internal temperature range of typical days in summer (35.9 C), being able to reduce internal temperature by 2.0 C durin g warmer periods of the day and about 4.0 C in the external environment, compared with the tiles roof, being efficient on the local microclimate modification.

O uso telhados verdes oferece benefícios como: moderação dos valores da temperatura no interior de edificações e contenção temporária da água de chuva, limpeza de poluentes atmosféricos, além de favorecer aspectos ecológicos. Poucos estudos científicos foram realizados no sentido de adaptar as técnicas contemporâneas e a indicação de espécies apropriadas ao sistema de telhado verde extensivo, originadas de regiões de clima temperado para as condições dos climas tropicais. O objetivo desta pesquisa foi identificar espécies com potencial de uso em telhado verde em sistema extensivo, quantificando a reação das plantas à variação de diferentes profundidades de substrato, em situações limitadas de manutenção, no aspecto de irrigação e nutrição do solo. Procurou-se também registrar o comportamento térmico do solo, a fim de verificar a influência da vegetação no aquecimento da parte inferior do solo em relação a distintas profundidades de substrato. Os vegetais foram plantados em setembro de 2009 aplicados em 27 plataformas de teste. Foram cultivadas três espécies de plantas das famílias Fabaceae (Arachis repens Handro), Poaceae (Paspalum notatum Flügge) e Ruscacea (Ophiopogon japonicus (L.F. Ker Gawl)), sob três tratamentos de profundidades de substrato, 0.05, 0.075 e 0.10 m. Quantificou-se mensalmente a porcentagem de cobertura vegetal, crescimento vertical e de sobrevivência, com encerramento ao final de um ciclo anual. O comportamento térmico dos solos nos diferentes tratamentos foi registrado automaticamente por meio de sensores. Os resultados indicaram a espécie Ophiopogon japonicus, em solos de 0.10 m, como a que apresentou o melhor desempenho entre as três examinadas, seguida por Paspalum notatum. Todas as espécies cultivadas em solos de 0.10 m apresentaram resultados satisfatórios quanto a cobertura do solo, crescimento vertical e sobrevivência, em relação ao cultivo em profundidades menores de substrato. O cultivo em menor profundidade de solo (0.05 m) revelou baixo valor de sobrevivência para todas as espécies durante o período de poucas chuvas. O crescimento vertical foi satisfatório para todas as espécies analisadas, dispensando manutenção com poda regular. Os resultados de comportamento térmico indicaram melhor desempenho de solos à profundidade de 0.10 m, independente do tipo de planta cultivado. Concluiu-se que solos de menor espessura são mais dependentes de cobertura vegetal para minimizar seu aquecimento e que os solos de maior espessura o fazem com menor dependência da vegetação. O melhor desempenho térmico foi observado em solos de 0.10 m, em relação às profundidades menores, embora não variasse seu comportamento térmico significativamente com o cultivo das três diferentes espécies de plantas, referente aos valores de cobertura atingidos neste experimento. / The uses of green roofs provide benefits such as moderation of the temperature inside buildings, temporary containment of rainwater, cleaning of air pollutants, in addition to promoting ecological aspects. Few scientific studies have been conducted to adapt contemporary techniques and indication of appropriate species for extensive green roof system, originated from temperate regions to the conditions of tropical climates. The objective of this research was to identify species with potential for use in green roof in the extensive system, quantifying the response of plants to variation of different depths of substrate, in limited situations of maintenance in respect of irrigation and soil nutrition. Was searched register the thermal behavior of soil in order to determine the influence of vegetation on the warming of the lower soil depths for different substrates. The plants were planted in september 2009, applied in 27 platforms. There were three species of cultivated plants of the families Fabaceae (Arachis repens Handro), Poaceae (Paspalum notatum Flügge) and Ruscacea (Ophiopogon japonicus (L.F.) Ker Gawl) under three treatments of substrate depths, 0.05, 0.075 and 0.10 m. Was quantified the percentage of monthly vegetation cover, vertical growth and survival, with closing at the end of an annual cycle. The thermal behavior of soils under different treatments was recorded using sensors. The results indicated that Ophiopogon japonicus in 0.10 m soils, showed the best performance among the three examined. All species grown in 0.10 m of soils had been satisfactory results of soil cover, vertical growth and survival in relation to culture in shallower substrate. The species Arachis repens showed the highest sensitivity to the depth and water stress during the autumn and winter, requiring more necessity of maintenance. Cultivation in shallower soil (0.05 m) showed low survival value for all species during the short rains. The vertical growth was satisfactory for all species analyzed, of which the greatest height reached was Ophiopogon japonicus without requiring regular maintenance pruning. The results indicated better performance thermal behavior of soil to a depth of 0.10 m, regardless of the type of plant grown. It was concluded that soils of lesser thickness are dependent on vegetation cover to minimize your heating, and the soils with more thickness are less dependence on the vegetation. The best thermal performance was observed in soils of 0.10 m compared to shallower depths, but did not vary significantly its thermal behavior with the cultivation of three different species of plants, referring to amounts of coverage achieved in this experiment.

Beside the point of whether the country is developed or underdeveloped, energy crisis is a common scene all over the world. In order to balance energy supply and demand, either one has to increase the supply or decrease the demand. The latter seems to be the better choice since we have limited sources of energy. About 20% - 40% of energy produced by a country is being consumed by HVACs in buildings. Hence much e ort is towards energy conservation in buildings. Around 30% of the building energy consumption in India is due to cooling load. Previous studies have shown that around 60% of the heat due to solar radiation enters through the roof of the building. The present work aims to reduce the heat load entering through the roof by coming up with a better roofing technique for moderate climatic regions. In the present work, enclosures with the side walls and the floor (bottom slab) insulated has been studied both numerically and experimentally. Heat transfer between the ambient and enclosure is only through the roof (top slab). Six common roofing types have been studied in this thesis. Reinforced cement concrete (RCC) roof Mangalore tile roof Thatched roof GI Sheet roof and Concrete roof with lawn (green roof) Concrete roof with a layer of wet sand The experimental studies have been carried out to understand heat transfer through these roofs. A comparative study of all six types of roofs has been done. Apart from this, the effect of a shade net on room models with bare RCC roof and GI sheet roof is also studied and presented in this thesis. Each enclosure has a height of 0.3m and the sides are 1m in size. Mangalore tile and thatched roofs are inclined to the horizontal. To understand the heat flow process, the temperature variations of different surfaces and enclosure air, and, air temperatures near the top and bottom slabs were recorded. In addition, weather conditions such as solar radiation, ambient air temperature, and wind speed are recorded. The details of the experimental set up are given in chapter 3. In chapter 2, a mathematical model to determine the temperature variations in the enclosure is given. All the three modes of heat transfer (conduction, convection and radiation) are present and the system is unsteady. The objective is to find the temperatures of the walls and the enclosure air temperature. Heat flows either from surroundings to the enclosure or from enclosure to the surroundings through the walls of the enclosure. As the solar radiation data is known for a given location, un-steady heat conduction equation is solved for the walls of the enclosure with heat flux boundary conditions to solve for the temperatures. Standard correlations have been used for calculating the convective heat transfer to the ambient and in the enclosure. Most importantly, the experiments conducted were field experiments. The main objective of the study had been to understand the effect of roof on thermal comfort conditions inside the scaled model rooms under five different weather conditions which are commonly observed in warm tropics: (1)summer, (2)winter, (3)cloudy, (4)unsteady, and, (5)rainy. The details of weather conditions have been discussed in chapter 4. In the present analysis, various issues were looked upon such as, temperature values, time lag, thermo-physical properties of the roof material, weather conditions, average over a 24 hours cycle etc. For the comparative analysis, bare RCC roof has been assumed to the base case as most of the buildings are built with RCC roof (for example, in India, around 29% of the buildings have RCC roof, as per 2011 census). On one side we have passive cooling techniques (lawn over RCC roof and wet sand over RCC roof), and, on the other side we have breathing roofs (Mangalore tile roof and thatched roof). Apart from these, the GI sheet roof is commonly used for small scale industries and residential houses. It has been observed that the concrete roof with lawn (hereafter called as lawn over RCC roof ) being the best one among the considered six roofs. Having lawn over RCC roof could result reduction in both solar gain and the diurnal variation of enclosure inside temperatures. The range of temperature variation was least disturbed due to change in weather conditions. In the case of wet sand over RCC roof, the diurnal variations of enclosure inside temperatures were relatively higher as compared with those in the lawn over RCC roof case. As far as breathing roofs are concerned, the two were found to be better than bare RCC roof with thermal comfort as point of view. On the other hand, breathing effects are found to be better in case of Mangalore tile roof than in case of thatched roof. GI sheet roof was found to be the worst among considered for thermal comfort. The effect of using shade net over RCC and GI sheet roof proves to have good potential to reduce cooling load with negligible adverse effects during night time. Detailed discussion of results has been done in chapter 4. Numerical simulations have been carried out for the case of model room with bare RCC roof. A comparative analysis of both experimental and numerical results has been discussed in chapter 5. The important conclusions are discussed in chapter 6.