scholarly journals A COMPARISON OF HEAT PERFORMANCE BETWEEN GREEN ROOFS ON CONCRETE AND GREEN ROOFS ON CORRUGATED ZINC

2021 ◽  
Vol 47 (2) ◽  
pp. 55-64
Author(s):  
Sri Yuliani ◽  
Gagoek Hardiman ◽  
Erni Setyowati
Keyword(s):  
Computer Simulation ◽  
Thermal Performance ◽  
Small Difference ◽  
Green Roof ◽  
Green Roofs ◽  
Roof Material ◽  
Temperature Reduction ◽  
The Difference

Green roofs are generally applied to concrete roofed buildings. This study compares the thermal performance of green roofs that occur in corrugated concrete and zinc to expand green roof innovation. The study experimented on a method using the 2011 Ecotect computer simulation. The results showed that the difference in temperature reduction in corrugated zinc was higher than in concrete. Changes in heat outside the roof space on both have a number that has a relatively small difference, but the difference in heat is visible in the inner space. Based on the thermal performance of the roof, the use of corrugated zinc roofs as the base of the green roof in the building could be an alternative green roof material besides concrete.

THERMAL PERFORMANCE OF AN EXTENSIVE GREEN ROOF UNDER SEMI-ARID CONDITIONS IN CENTRAL ARGENTINA

2021 ◽  
Vol 16 (1) ◽  
pp. 17-42
Author(s):  
Lelia Imhof ◽  
Edgardo Suárez ◽  
Natalia Cáceres ◽  
Federico Robbiati ◽  
Cecilia Cáceres ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Green Roof ◽  
Green Roofs ◽  
Climatic Conditions ◽  
Urban Environments ◽  
Climate Conditions ◽  
Average Temperature ◽  
Arid Conditions ◽  
The Difference ◽  
Extensive Green Roofs

ABSTRACT Extensive green roofs improve the provision of ecosystem services in urban environments, particularly in semiarid regions. The aim of this paper is to compare their thermal performance during six months between two rooms, one with a green roof and the other with a conventional roof, in Córdoba (Argentina). The room with a green (planting) roof showed a lower inside surface temperature since the beginning of the study than the control room (between 5–6°C of difference). During the selected period, the indicators such as temperature amplitude (the difference between the maximum and the average temperature) and the anti-interference characteristics of the layers to the outdoor air temperature are produced a better performance for the green roof compared to the conventional roof. The pattern of a better performance was consistent across the study for the green roof, characterized by a higher cooling and warming of the roof surface during the day and night, respectively. The green roof was more effective at blocking an upward heat flux during the day and suppressing heat loss during the night. Evaporation, conductive flux and climatic conditions seem to dominate the thermal performance of green roofs in areas with semiarid climate conditions.

scholarly journals COBERTURA E FACHADA VERDE:

2019 ◽  
Vol 8 (2) ◽  
pp. 89-100
Author(s):  
Thiago Youzi Kussaba Kayano ◽  
Nuria Perez Gallardo ◽  
Bruno César dos Santos ◽  
Mauricio Sanches Duarte Silva ◽  
Rafael Perussi ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Thermal Performance ◽  
Green Roof ◽  
Green Roofs ◽  
Sao Paulo ◽  
Test Cell ◽  
São Paulo ◽  
Control Test ◽  
Green Façade ◽  
Green Facade

Com a busca de alternativas para melhorar o conforto ambiental em ambientes construídos, os sistemas de fachadas e tetos verdes aparecem como uma opção para melhoria, em especial, do conforto térmico. Utilizando-se de um episódio climático representativo no mês de junho de 2016, analisou-se comparativamente o comportamento térmico de uma célula de teste com fachada e teto verde e uma célula de controle para avaliação do desempenho térmico em dia crítico experimental de frio. O experimento foi realizado no Centro de Recursos Hídricos e Estudos Ambientais (CRHEA) da Universidade de São Paulo (USP), em Itirapina-SP. Os resultados indicaram que a célula de teste com fachada e teto verde possui um melhor desempenho térmico em comparação à célula de controle. Palavras-chave: desempenho térmico, episódio climático representativo, comportamento térmico, fachada verde, cobertura verde. Abstract In searching for better thermal behavior alternatives in building environments green facade systems and green roofs emerge as an improvement option, particularly in thermal comfort. Using a representative climate episode to analyze the month of June of 2016 we studied the thermal performance of a green façade and green roof test cell and a control test cell in experimental critical cold day. The experiment was made in Water Resource and Environmental Studies Center (CRHEA) of University of São Paulo (USP), in Itirapina-SP. The results indicated the green wall and green roof test cell have a better thermal performance than control test cell. Keywords: Thermal performance, climatic representative episode, thermal behavior, green façade, green cover.

scholarly journals Determining Thermal Specifications for Vegetated GREEN Roofs in Moderate Winter Climates

2015 ◽  
Vol 9 (13) ◽  
pp. 208
Author(s):  
Christoph Maria Ravesloot
Keyword(s):  
Thermal Insulation ◽  
Thermal Performance ◽  
Energy Use ◽  
Green Roof ◽  
Green Roofs ◽  
Physical Parameters ◽  
Winter Climate ◽  
Theoretical Contribution ◽  
Winter Conditions ◽  
U Value

<p class="zhengwen">Because local weather conditions in moderate climates are changing constantly, heat transfer specifications of substrate and vegetation in vegetated green roofs also change accordingly. Nevertheless, it is assumed that vegetated green roofs can have a positive effect on the thermal performance of construction in winter conditions. Is there proof from scientific research and field testing for this assumption? To answer this question, research is conducted with the main research question: Which parameters defining thermal performance for vegetated green-roof construction for a moderate winter climate like that in the Netherlands can be determined from existing literature, and how do these parameters influence thermal performance? Literature research was executed on monitoring and testing of thermal specifications of vegetated green roofs. Models with physical parameters on vegetated green roofs were studied and compared. The first goal was to make a list of all physical parameters and corresponding variables valid in the Dutch moderate-winter climate. None of the models that were found in the literature seemed to cover all physical processes. These models use parameters and variables to calculate the overall u-value of substrate and vegetation. Nevertheless, one nearly complete model was used for a sensitivity test on variables. Maximum and minimum values of variables were calculated in the model to determine the influence on the outcome in terms of u-value. From this analysis, a distinction could be made between variables influencing the u-value strongly and other variables influencing the outcome weakly.</p><p class="zhengwen">The modelling showed that three variables were influencing the model calculations moderately strongly and therefore the thermal performance of the vegetated green-roof substrate and vegetation. These variables are not consistent with parameters modeling or calculating u-value in constructions. This finding means that contribution to thermal insulation by extensive vegetated green-roof substrate and vegetation in terms of u-value would be negligible. Only a small theoretical contribution to thermal insulation can be argued from weak variables. To be sure about this small theoretical contribution to the u-value of the roof construction, this u-value was used as input for energy-use calculations for residential buildings. These calculations show that such a small increase of the u-value leads to no visible reduction in energy use for heating in winter conditions. The contribution is negligible compared to the influence of the u-value from extra insulation under the roof.</p>For vegetated green roofs in such moderate winter climates as in the Netherlands, additional u-value will have to be proven specifically, because the modelling shows that, in general, no contribution to thermal insulation can be expected.

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.

Analyses of the Insulating Capacity of Green Roofs Made of Phenolic Resin Board with Vegetation Coverage

2011 ◽  
Vol 71-78 ◽  
pp. 4491-4495
Author(s):  
Yu Kuang Zhao ◽  
Lei Wei ◽  
Chi Chau Lien ◽  
Wen Pei Sung
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Phenolic Resin ◽  
Construction Material ◽  
Green Roof ◽  
Green Roofs ◽  
Vegetation Coverage ◽  
Insulation Material ◽  
Green Vegetation ◽  
The Difference

The global warming effect causes climate change. Especially, it directly affects the weather pattern of Taiwan. The temperature continually rising leads to higher energy consumption for building air-conditioning. The phenolic resin board is a very good heat insulation and eco-friendly construction material. Otherwise, a green roof covered with living plants for the purpose to reduce heat effect in building are widely used in the world. Therefore, in this research, the phenolic resin board is used as an experimental roof insulation material in a green roof that is covered with living plants for the objective of reducing summer building air conditioning energy consumption and cost. During summer, the difference between inside and outside temperatures across the phenolic resin board exposed to direct sun shine is as high as 8°C±2°C. The combined insulation technology using phenolic resin board and planted green vegetation coverage on the roof will also contribute to a green and aesthetic environment.

Nutrient leaching from extensive green roofs with different substrate compositions: a laboratory study

2017 ◽  
Vol 77 (4) ◽  
pp. 1007-1014 ◽  
Author(s):  
Wei Zhang ◽  
Xing Zhong ◽  
Wu Che
Keyword(s):  
Peat Soil ◽  
Green Roof ◽  
Green Roofs ◽  
Nutrient Leaching ◽  
Nitrogen And Phosphorus ◽  
Cumulative Emission ◽  
Term Operation ◽  
Artificial Rainfall ◽  
The Difference ◽  
Extensive Green Roofs

Abstract To investigate nutrient leaching from extensive green roofs, green roof platforms were established to investigate the effluent quantity and quality during artificial rainfall. When the influent volume reached three times the empty bed volume, for which the cumulative rainfall was around 300 mm, the effluent TP and COD concentrations of green roof platforms filled with peat soil did not tend to stabilize. For a long-term operation, the substrate depths had little significant influence on TN, TP and COD concentrations of the green roof effluents. A normalized cumulative emission process method was proposed to discuss the difference in various pollutant leaching processes. Obvious differences in the leaching process of different contaminants for green roof platforms filled with various substrates were observed. For the green roof filled with modified substrates, the nitrogen and phosphorus pollutant leaching rates were relatively high in the initial stage of green roof operation and the phosphorus leaching rate was higher than that of nitrogen. The green roof is a sink for TN, but not for TP and COD in this study. The outcomes are critical for the selection of green roof substrates and also contribute to green roof maintenance.

Thermal Performance Evaluation of Green Roofs in Warm Humid Climates: A Case of Residential Buildings in Madurai, India

2016 ◽  
Vol 692 ◽  
pp. 82-93 ◽  
Author(s):  
A Madhumathi ◽  
S. Radhakrishnan ◽  
R. Shanthipriya
Keyword(s):  
Thermal Properties ◽  
Thermal Performance ◽  
Energy Demand ◽  
Residential Buildings ◽  
Green Roof ◽  
Green Roofs ◽  
Outdoor Environment ◽  
Thermal Mass ◽  
Second Phase ◽  
Rapid Urbanization

Green roof application on real residential buildings in Tamilnadu, India is very limited and mostly concentrated in major cities mainly for visual purposes. There is not enough research has been conducted to boost up the benefits of green roof system in Warm and Humid weather in India. Green roofs have the potential to improve the thermal performance of a roofing system through shading, insulation, evapotranspiration and thermal mass, thus reducing a building’s energy demand for space conditioning. To quantify the thermal performance and energy efficiency of green roofs an experimental investigation was done in residential buildings of Madurai, Tamilnadu, India. This paper refers to the analysis of the thermal properties and indoor thermal performance study of the green roof. The investigation were implemented in two phases: during the first phase, extended surface, air temperature and relative humidity measurements were taken at the indoor and outdoor environment of the buildings where the green roof had installed and during the second phase of the study, the thermal properties of the green roof, as well as, the cooling potential were examined. Results showed vegetative roofs reduced heat gain compared to the white reflective roofs and conventional reinforced cement concrete due to the thermal mass, extra insulation, and evapo-transpiration associated with the vegetative roofing systems. The results also proved that green roofs provide acceptable indoor thermal performance with respect to the other conventional roofs while re-establishing the relationship between human and environment, which have been destroyed due to the rapid urbanization.

Experimental and Simulating Analyses of the Insulating Efficiency of Green Roofs

2011 ◽  
Vol 121-126 ◽  
pp. 2453-2458
Author(s):  
Yu Kuang Zhao ◽  
Chi Chau Lien ◽  
Lei Wei ◽  
Wen Pei Sung
Keyword(s):  
Energy Consumption ◽  
Phenolic Resin ◽  
Cfd Simulation ◽  
Global Climate ◽  
Green Roof ◽  
Green Roofs ◽  
Vegetation Coverage ◽  
Insulation Material ◽  
Data Simulation ◽  
The Difference

The global climate change directly affects the weather pattern of Taiwan. Some research achievements show that buildings will decrease the indoor room temperatures by 1oC during summer and increase the indoor room temperature by 1oC during winter with 6%~10% savings of energy consumption. In this research, the phenolic resin board is used as an experimental roof insulation material in a green roof that is covered with living plants for the objective of reducing summer building air conditioning energy consumption and cost. The influence of roofing materials with various insulation capacities on the building interior temperature is simulated in this study using the basic thermal data measured in the laboratory. Analysis results of computational fluid dynamics, CFD simulation of the temperatures are close to the measured data. Simulation of the insulation capacity of the green roof indicates that the difference between outside and inside temperature is as high as 29°C that demonstrates the insulation capacity of the phenolic resin board. In addition to save energy, the combined insulation technology using phenolic resin board and planted green vegetation coverage on the roof will also contribute to a green and aesthetic environment.

scholarly journals Wpływ miąższości reaktywnej warstwy drenażowej na odpływ fosforanów z zielonego dachu

2017 ◽  
Vol 26 (4) ◽  
pp. 447-456
Author(s):  
Agnieszka Karczmarczyk ◽  
Agnieszka Kocik
Keyword(s):  
Green Roof ◽  
Optimal Solution ◽  
Column Experiment ◽  
Green Roofs ◽  
Reactive Material ◽  
Drainage Layer ◽  
Roof Material ◽  
Substrate Layer ◽  
Simulated Precipitation ◽  
Water Outflow

The green roof runoff may be contaminated with phosphorus. The source of P pollution can be a substrate layer. The research was carried out to determine an optimal ratio of P-reactive drainage layer (RM) to substrate layer (S) in a green roof construction. The main goal of conducted column experiment, was to examine P-removal efficiency of drainage layers in different thickness. The green roof material used in the experiment is a commercially available substrate for intensive roofs. It has been confirmed that the substrate can act as a source of phosphorus occurring in leachate from green roofs. It has been found that the P-reactive drainage layer of Polonite® in thickness of 2 and 5 cm reduces phosphate load in runoff. The load of phosphorus discharged from the columns amounted to 0.091; 0.032 and 0.02 mg P-PO4 for K1 (S:RM=10:1), K2 (S:RM=10:2) and K3 (S:RM=10:5). Layer of the substrate relative to reactive material layer of 10: 2 was considered as an optimal solution. In relation to the quality of water supplied an increase of pH and conductivity in runoff was observed. The P-reactive drainage layer and its thickness had no effect on these parameters. All the columns reduced water outflow by approximately 40% compared to the volume of simulated precipitation.

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