scholarly journals The GREENROOF module (v7.3) for modelling green roof hydrological and energetic performances within TEB

2013 ◽  
Vol 6 (1) ◽  
pp. 1127-1172 ◽  
Author(s):  
C. S. de Munck ◽  
A. Lemonsu ◽  
R. Bouzouidja ◽  
V. Masson ◽  
R. Claverie
Keyword(s):  
Green Roof ◽  
Green Roofs ◽  
Building Envelope ◽  
Local Climate ◽  
Extensive Green Roof ◽  
Hydrological Characteristics ◽  
Drainage Layers ◽  
Evaluation Exercise ◽  
Climate Forcings ◽  
The Impact

Abstract. The need to prepare cities for climate change adaptation requests the urban modeller community to implement within their models sustainable adaptation strategies to be tested against specific city morphologies and scenarios. Greening city roofs is part of these strategies. In this context, a GREENROOF module for TEB (Town Energy Balance) has been developed to model the interactions between buildings and green roof systems at the scale of the city. This module allows one to describe an extensive green roof composed of four functional layers (vegetation – grasses or sedums, substrate, retention/drainage layers and artificial roof layers) and to model vegetation-atmosphere fluxes of heat, water and momentum, as well as the hydrological and thermal fluxes throughout the substrate and the drainage layers, and the thermal coupling with the structural building envelope. TEB-GREENROOF (v7.3) is therefore able to represent the impact of climate forcings on the functioning of the green roof vegetation and, conversely, the influence of the green roof on the local climate. A calibration exercise to adjust the model to the peculiar hydrological characteristics of the substrates and drainage layers commonly found on green roofs is performed for a case study located in Nancy (France) which consists of an extensive green roof with sedums. Model results for the optimum hydrological calibration show a good dynamics for the substrate water content which is nevertheless under-estimated but without impacting too much the green roof temperatures since they present a good agreement with observations. These results are encouraging with regard to modelling the impact of green roofs on thermal indoor comfort and energy consumption at the scale of cities, for which GREENROOF will be running with the building energy version of TEB, TEB-BEM. Moreover, the green roof studied for GREENROOF evaluation being a city-widespread type of extensive green roof, the hydrological characteristics derived through the evaluation exercise will be used as the standard configuration to model extensive green roofs at the scale of cities.

scholarly journals The GREENROOF module (v7.3) for modelling green roof hydrological and energetic performances within TEB

2013 ◽  
Vol 6 (6) ◽  
pp. 1941-1960 ◽  
Author(s):  
C. S. de Munck ◽  
A. Lemonsu ◽  
R. Bouzouidja ◽  
V. Masson ◽  
R. Claverie
Keyword(s):  
Water Content ◽  
Green Roof ◽  
Green Roofs ◽  
Model Interaction ◽  
Drainage Layer ◽  
Extensive Green Roof ◽  
Hydrological Characteristics ◽  
Drainage Layers ◽  
The Impact

Abstract. The need to prepare cities for climate change adaptation requests the urban modeller community to implement sustainable adaptation strategies within their models to be tested against specific city morphologies and scenarios. Greening city roofs is part of these strategies. In this context, the GREENROOF module for TEB (town energy balance) has been developed to model the interactions between buildings and green roof systems at the scale of the city. This module, which combines the ISBA model (Interaction between Soil Biosphere and Atmosphere) and TEB, allows for one to describe an extensive green roof composed of four functional layers (vegetation – grasses or sedums; substrate; retention/drainage layers; and artificial roof layers) and to model vegetation-atmosphere fluxes of heat, water and momentum, as well as the hydrological fluxes throughout the substrate and the drainage layers, and the thermal fluxes throughout the natural and artificial layers of the green roof. TEB-GREENROOF (SURFEX v7.3) should therefore be able to represent the impact of climate forcings on the functioning of green roof vegetation and, conversely, the influence of the green roof on the local climate. An evaluation of GREENROOF is performed for a case study located in Nancy (France) which consists of an instrumented extensive green roof with sedums and substrate and drainage layers that are typical of this kind of construction. After calibration of the drainage layer hydrological characteristics, model results show good dynamics for the substrate water content and the drainage at the green roof base, with nevertheless a tendency to underestimate the water content and overestimate the drainage. This does not impact too much the green roof temperatures, which present a good agreement with observations. Nonetheless GREENROOF tends to overestimate the soil temperatures and their amplitudes, but this effect is less important in the drainage layer. These results are encouraging with regard to modelling the impact of green roofs on thermal indoor comfort and energy consumption at the scale of cities, for which GREENROOF will be running with the building energy version of TEB – TEB-BEM. Moreover, with the green roof studied for GREENROOF evaluation being a type of extensive green roof widespread in cities, the type of hydrological characteristics highlighted for the case study will be used as the standard configuration to model extensive green roof impacts at the scale of cities.

scholarly journals A Comparison of Energy and Thermal Performance of Rooftop Greenhouses and Green Roofs in Mediterranean Climate: A Hygrothermal Assessment in WUFI

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2030
Author(s):  
Mansoureh Gholami ◽  
Alberto Barbaresi ◽  
Patrizia Tassinari ◽  
Marco Bovo ◽  
Daniele Torreggiani
Keyword(s):  
Thermal Performance ◽  
Mediterranean Climate ◽  
Green Roof ◽  
Green Roofs ◽  
Energy Performance ◽  
Building Envelope ◽  
Considerable Proportion ◽  
Urban Context ◽  
Cooling Period ◽  
The Impact

In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs.

scholarly journals The impact of the building envelope with the green living systems on the built environment

2018 ◽  
Vol 22 (Suppl. 4) ◽  
pp. 1033-1045
Author(s):  
Predrag Zivkovic ◽  
Dragana Dimitrijevic-Jovanovic ◽  
Zana Stevanovic
Keyword(s):  
Energy Consumption ◽  
Urban Areas ◽  
Heat Waves ◽  
Urban Ecosystems ◽  
Green Roofs ◽  
Building Envelope ◽  
Living Systems ◽  
Local Climate ◽  
Run Off ◽  
The Impact

Altering the surface cover of an area causes the change in the environment. By erecting buildings change in the flow of energy and matter through the urban ecosystems occurs creating multiple environmental problems. Built areas exert considerable influence over their local climate, amplifying problems such as heat waves, air pollution, and flooding. Greening the building envelope these problems can be partially mitigated. By combining nature and built areas in their designs, architects and urban planners can respond to these serious human health and welfare issues and restore the environmental quality of dense urban areas. Green living systems are not the only solution for new designs. Retrofitting existing buildings by altering the buildings' surficial properties can reduce buildings' energy consumption in case of older buildings with poor existing insulation. Implementation of green living systems in the building envelope, greening horizontal surfaces with intensive and extensive green roofs or using vegetation in vertical greening systems for fa?ades, is a strategy that provides ecological, economic, and social benefits. This review paper presents collected evidence of effects and explores the important role that the green living systems can play in the dense urban areas. Benefits such as heat island amelioration, reduction of buildings energy consumption, air quality and indoor and outdoor comfort conditions improvement, stormwater management and improved water run-off quality, will be mainly considered.

scholarly journals Seismic Performance of a Green Roof Structure

2021 ◽  
Vol 13 (8) ◽  
pp. 4278
Author(s):  
Svetlana Tam ◽  
Jenna Wong
Keyword(s):  
Green Roof ◽  
Time History ◽  
Green Roofs ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Roof Structure ◽  
Nonlinear Time History Analyses ◽  
Vegetated Roofs ◽  
Nonlinear Time History ◽  
The Impact

Sustainability addresses the need to reduce the structure’s impact on the environment but does not reduce the environment’s impact on the structure. To explore this relationship, this study focuses on quantifying the impact of green roofs or vegetated roofs on seismic responses such as story displacements, interstory drifts, and floor level accelerations. Using an archetype three-story steel moment frame, nonlinear time history analyses are conducted in OpenSees for a shallow and deep green roof using a suite of ground motions from various distances from the fault to identify key trends and sensitivities in response.

scholarly journals Hydrologic Performance of an Extensive Green Roof under Intensive Rain Events: Results from a Rain-Chamber Simulation

2021 ◽  
Vol 13 (6) ◽  
pp. 3078
Author(s):  
Elena Giacomello ◽  
Jacopo Gaspari
Keyword(s):  
Water Retention ◽  
Green Roof ◽  
Green Roofs ◽  
International Standards ◽  
Dimensionless Number ◽  
Runoff Coefficient ◽  
Retention Performance ◽  
Extensive Green Roof ◽  
Rain Events ◽  
Hydrologic Performance

The water storage capacity of a green roof generates several benefits for the building conterminous environment. The hydrologic performance is conventionally expressed by the runoff coefficient, according to international standards and guidelines. The runoff coefficient is a dimensionless number and defines the water retention performance over a long period. At the scale of single rain events, characterized by varying intensity and duration, the reaction of the green roof is scarcely investigated. The purpose of this study is to highlight how an extensive green roof—having a supposed minimum water performance, compared to an intensive one—responds to real and repetitive rain events, simulated in a rain chamber with controlled rain and runoff data. The experiment provides, through cumulative curve graphs, the behavior of the green roof sample during four rainy days. The simulated rain events are based on a statistical study (summarized in the paper) of 25 years of rain data for a specific location in North Italy characterized by an average rain/year of 1100 mm. The results prove the active response of the substrate, although thin and mineral, and quick draining, in terms of water retention and detention during intense rain events. The study raises questions about how to better express the water performance of green roofs.

scholarly journals State-of-the-Art Green Roofs: Technical Performance and Certifications for Sustainable Construction

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 69 ◽  
Author(s):  
Alejandra Naranjo ◽  
Andrés Colonia ◽  
Jaime Mesa ◽  
Heriberto Maury ◽  
Aníbal Maury-Ramírez
Keyword(s):  
Environmental Assessment ◽  
State Of The Art ◽  
Green Roof ◽  
Green Roofs ◽  
Assessment Method ◽  
Assessment System ◽  
Sustainable Construction ◽  
Runoff Water ◽  
Technical Performance ◽  
The Impact

Green roof systems, a technology which was used in major ancient buildings, are currently becoming an interesting strategy to reduce the negative impact of traditional urban development caused by ground impermeabilization. Only regarding the environmental impact, the application of these biological coatings on buildings has the potential of acting as a thermal, moisture, noise, and electromagnetic barrier. At the urban scale, they might reduce the heat island effect and sewage system load, improve runoff water and air quality, and reconstruct natural landscapes including wildlife. In spite of these significant benefits, the current design and construction methods are not completely regulated by law because there is a lack of knowledge of their technical performance. Hence, this review of the current state of the art presents a proper green roof classification based on their components and vegetation layer. Similarly, a detailed description from the key factors that control the hydraulic and thermal performance of green roofs is given. Based on these factors, an estimation of the impact of green roof systems on sustainable construction certifications is included (i.e., LEED—Leadership in Energy and Environment Design, BREEAM—Building Research Establishment Environmental Assessment Method, CASBEE—Comprehensive Assessment System for Built Environment Efficiency, BEAM—Building Environmental Assessment Method, ESGB—Evaluation Standard for Green Building). Finally, conclusions and future research challenges for the correct implementation of green roofs are addressed.

The biodiversity of temperate extensive green roofs – a review of research and practice

2016 ◽  
Vol 62 (1-2) ◽  
pp. 44-57 ◽  
Author(s):  
Christine Thuring ◽  
Gary Grant
Keyword(s):  
Green Roof ◽  
Green Roofs ◽  
Ecological Design ◽  
Ecological Research ◽  
Extensive Green Roof ◽  
Research And Practice ◽  
Climatic Regions ◽  
History Of ◽  
Research To Policy ◽  
Extensive Green Roofs

From its beginnings in Germany in the twentieth century, a thriving extensive green roof industry has become established in many countries in temperate climates. Based upon the success of the industry, and with an expectation that this technology will be adopted in other climates, this review of the ecological research of extensive green roofs aims to evaluate the application of this knowledge. The modern extensive green roof is the product of research in the 1970s by German green roof pioneers; the selection of suitable species from analogue habitats led to green roof vegetation dominated by drought tolerant taxa. The commercial success of extensive green roof systems can be attributed to engineering and horticultural research, to policy mechanisms in some places, and to a market that encourages innovation, and the origins in ecological design are now easily overlooked. Some of the work reviewed here, including the classification of spontaneous roof vegetation into plant communities, is not widely known due to its confinement to the German literature. By re-visiting the history of the extensive green roof and reviewing the ecological research that has contributed to our understanding of it, the intention is, for this paper, to inform those considering green roofs in other climatic regions, to apply an ecologically informed approach in using local knowledge for developing installations that are suited to the bioregion in which they occur. Finally the paper considers some future directions for research and practice.

scholarly journals Is Smart Growth a smart adaptation strategy?: Examining Ontario's proposed growth under climate change

2004 ◽  
Vol 71 (424-426) ◽  
pp. 57-62
Author(s):  
Brad Bass
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Urban Areas ◽  
Green Roof ◽  
Smart Growth ◽  
Green Roofs ◽  
Adaptation Strategy ◽  
University Of Toronto ◽  
Conducting Research ◽  
The Impact

The author is a member of Environment Canada's Adaptation and Impact Research Group, located in the Centre for Environment at the University of Toronto. His primary research interests include the use of ecological technologies in adapting urban areas to atmospheric change, the impacts of climate change on the energy sector, and the characteristics of adaptable systems. His current work on ecological technologies includes green roofs, vertical gardens and living machines. Dr Bass has been involved in two major projects, in Ottawa and Toronto, to evaluate the impact of green roofs on the urban heat island, energy consumption, stormwater runoff and water quality. Currently, Dr Bass is conducting research on integrating green roof infrastructure with other vegetation strategies at a community scale, simulating the impact of a green roof on the energy consumption of individual buildings.

scholarly journals Determination of the Physical, Chemical, and Hydraulic Characteristics of Locally Available Materials for Formulating Extensive Green Roof Substrates

2015 ◽  
Vol 25 (6) ◽  
pp. 774-784 ◽  
Author(s):  
Nikolaos Ntoulas ◽  
Panayiotis A. Nektarios ◽  
Thomais-Evelina Kapsali ◽  
Maria-Pinelopi Kaltsidi ◽  
Liebao Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Green Roof ◽  
Organic Amendments ◽  
Green Roofs ◽  
N Leaching ◽  
Extensive Green Roof ◽  
Second Stage

Several locally available materials were tested to create an optimized growth substrate for arid and semiarid Mediterranean extensive green roofs. The study involved a four-step screening procedure. At the first step, 10 different materials were tested including pumice (Pum), crushed tiles grade 1–2 mm (T1–2), 2–4 mm (T2–4), 5–8 mm (T5–8), 5–16 mm (T5–16), and 4–22 mm (T4–22); crushed bricks of either 2–4 mm (B2–4) or 2–8 mm (B2–8); a thermally treated clay (TC); and zeolite (Zeo). All materials were tested for their particle size distribution, pH, and electrical conductivity (EC). The results were compared for compliance with existing guidelines for extensive green roof construction. From the first step, the most promising materials were shown to include Pum, Zeo, T5–8, T5–16, and TC, which were then used at the second stage to develop mixtures between them. Tests at the second stage included particle size distribution and moisture potential curves. Pumice mixed with TC provided the best compliance with existing guidelines in relation to particle size distribution, and it significantly increased moisture content compared with the mixes of Pum with T5–8 and T5–16. As a result, from the second screening step, the best performing substrate was Pum mixed with TC and Zeo. The third stage involved the selection of the most appropriate organic amendment of the growing substrate. Three composts having different composition and sphagnum peat were analyzed for their chemical and physical characteristics. The composts were a) garden waste compost (GWC), b) olive (Olea europaea L.) mill waste compost (OMWC), and c) grape (Vitis vinifera L.) marc compost (GMC). It was found that the peat-amended substrate retained increased moisture content compared with the compost-amended substrates. The fourth and final stage involved the evaluation of the environmental impact of the final mix with the four different organic amendments based on their first flush nitrate nitrogen (NO3−-N) leaching potential. It was found that GWC and OMWC exhibited increased NO3−-N leaching that initially reached 160 and 92 mg·L−1 of NO3−-N for OMWC and GWC, respectively. By contrast, peat and GMC exhibited minimal NO3−-N leaching that was slightly above the maximum contaminant level of 10 mg·L−1 of NO3−-N (17.3 and 14.6 mg·L−1 of NO3−N for peat and GMC, respectively). The latter was very brief and lasted only for the first 100 and 50 mL of effluent volume for peat and GMC, respectively.

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