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 Green Roof Design Techniques to Improve Water Use under Mediterranean Conditions

Urban Science ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 14 ◽  
Author(s):  
Teresa Paço ◽  
Ricardo Cruz de Carvalho ◽  
Pedro Arsénio ◽  
Diana Martins
Keyword(s):  
Water Use ◽  
Green Roof ◽  
Green Roofs ◽  
Climatic Conditions ◽  
Native Plant ◽  
Additional Energy ◽  
Climate Conditions ◽  
Native Plant Species ◽  
Roof Design ◽  
Mediterranean Conditions

Green roof typology can vary depending on buildings structure, climate conditions, substrate, and plants used. In regions with hot and dry summers, such as the Mediterranean region, irrigation plays an essential role, as the highest temperatures occur during the driest period of the year. Irrigation might reduce the heat island effect and improve the cooling of buildings during this period, however, the added cost of maintenance operations and additional energy consumption could outrun the benefits provided by the project. Moreover, in situations where water is scarce or primarily channelled to other uses (e.g., domestic, agriculture or industry) during drought occurrence, it is advisable to implement green roof projects with the lowest use of water possible. The objective of the present work is to investigate solutions to optimize water use in green roofs under Mediterranean conditions, such as those of southern Europe. Two case studies are presented for Portugal, and potential techniques to reduce irrigation requirements in green roofs were tested. These addressed the use of native plant species, including the extreme type of a non-irrigated green roof (Biocrust roof) and techniques for plant installation. Plant drought tolerance was found to be an advantage in green roofs under these climatic conditions and, for the species studied, aesthetic value could be maintained when irrigation decreased.

scholarly journals Cladonia lichens on extensive green roofs: evapotranspiration, substrate temperature, and albedo

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 274 ◽  
Author(s):  
Amy Heim ◽  
Jeremy Lundholm
Keyword(s):  
Substrate Temperature ◽  
Water Loss ◽  
Vascular Plant ◽  
Green Roof ◽  
Green Roofs ◽  
Urban Environments ◽  
Substrate Temperatures ◽  
Extensive Green Roofs ◽  
Harsh Conditions ◽  
Vegetation Layer

Green roofs are constructed ecosystems that provide ecosystem services in urban environments. Shallow substrate green roofs subject the vegetation layer to desiccation and other environmental extremes, so researchers have evaluated a variety of stress-tolerant vegetation types for green roof applications. Lichens can be found in most terrestrial habitats.  They are able to survive extremely harsh conditions, including frequent cycles of desiccation and rehydration, nutrient-poor soil, fluctuating temperatures, and high UV intensities. Extensive green roofs (substrate depth <20cm) exhibit these harsh conditions, making lichens possible candidates for incorporation into the vegetation layer on extensive green roofs.  In a modular green roof system, we tested the effect ofCladonialichens on substrate temperature, water loss, and albedo compared to a substrate-only control. Overall, theCladoniamodules had significantly cooler substrate temperatures during the summer and significantly warmer temperatures during the fall.  Additionally, theCladoniamodules lost significantly less water than the substrate-only control. This implies that they may be able to benefit neighboring vascular plant species by reducing water loss and maintaining favorable substrate temperatures.

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.

scholarly journals Cladonia lichens on extensive green roofs: evapotranspiration, substrate temperature, and albedo

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 274 ◽  
Author(s):  
Amy Heim ◽  
Jeremy Lundholm
Keyword(s):  
Substrate Temperature ◽  
Water Loss ◽  
Vascular Plant ◽  
Green Roof ◽  
Green Roofs ◽  
Urban Environments ◽  
Substrate Temperatures ◽  
Extensive Green Roofs ◽  
Harsh Conditions ◽  
Vegetation Layer

Green roofs are constructed ecosystems that provide ecosystem services in urban environments. Shallow substrate green roofs subject the vegetation layer to desiccation and other environmental extremes, so researchers have evaluated a variety of stress-tolerant vegetation types for green roof applications. Lichens can be found in most terrestrial habitats.  They are able to survive extremely harsh conditions, including frequent cycles of desiccation and rehydration, nutrient-poor soil, fluctuating temperatures, and high UV intensities. Extensive green roofs (substrate depth <20cm) exhibit these harsh conditions, making lichens possible candidates for incorporation into the vegetation layer on extensive green roofs.  In a modular green roof system, we tested the effect ofCladonialichens on substrate temperature, water loss, and albedo compared to a substrate-only control. Overall, theCladoniamodules had significantly cooler substrate temperatures during the summer and significantly warmer temperatures during the fall.  Additionally, theCladoniamodules lost significantly less water than the substrate-only control. This implies that they may be able to benefit neighboring vascular plant species by reducing water loss and maintaining favorable substrate temperatures.

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.

scholarly journals A laboratory study to determine the use of polluted river sediment as a substrate for extensive green roofs

2018 ◽  
Vol 78 (11) ◽  
pp. 2247-2255 ◽  
Author(s):  
Wei Zhang ◽  
Xing Zhong ◽  
Wu Che ◽  
Huichao Sun ◽  
Hailong Zhang
Keyword(s):  
River Sediment ◽  
Peat Soil ◽  
River Sediments ◽  
Green Roof ◽  
Oxygen Demand ◽  
Green Roofs ◽  
Polluted River ◽  
Artificial Rainfall ◽  
Study Laboratory ◽  
Extensive Green Roofs

Abstract In this study, laboratory-scale green (e.g. living) roof platforms were established to assess the potential use of polluted river sediment in their substrate mixture. The mean runoff retention of the green roof platforms, which contained peat and/or river sediment, after 11 artificial rainfall events was &gt;72%, significantly higher than traditional roofs. However, green roof platforms that had been filled with peat soil showed chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) leaching. Green roofs that had used river sediment showed good leaching control for COD, TN and TP. The cumulative leaching masses from the green roofs contained 30% (COD), 42% (TN) and 47% (TP) as much as the total leaching mass from traditional roofs, and the Cu, Zn, Cd and Pb leaching risk from green roofs when river sediments are used as part of a substrate mixture was relatively low. Despite some nutrient leaching in the initial phase of runoff from the green roofs, river sediment has the potential to be used as a substrate for extensive green roofs.

Thermal performance assessment of extensive green roofs investigating realistic vegetation-substrate configurations

2018 ◽  
Vol 12 (3) ◽  
pp. 379-393 ◽  
Author(s):  
Stefano Cascone ◽  
Antonio Gagliano ◽  
Tiziana Poli ◽  
Gaetano Sciuto
Keyword(s):  
Performance Assessment ◽  
Thermal Performance ◽  
Green Roofs ◽  
Extensive Green Roofs

scholarly journals Analysis of roof greening technology impact on rain and meltwater retention

2020 ◽  
Vol 175 ◽  
pp. 11023
Author(s):  
Elena Sysoeva ◽  
Margarita Gelmanova
Keyword(s):  
High Efficiency ◽  
Green Roof ◽  
Experimental Studies ◽  
Green Roofs ◽  
Climatic Conditions ◽  
Water Runoff ◽  
Substrate Thickness ◽  
Runoff Reduction ◽  
The Usa ◽  
Analytical Review

Over the past 20 years, a large number of studies have been published on reducing storm runoff by various types of green roofs. This article analyzes the results of experimental studies presented in 39 publications on green roof runoff reduction in a climate similar to the climate of Russia: in Canada, the USA, Finland, Norway, France. An analytical review found that the ability of green roofs to retain rainfall varies from 20 to 99.5% depending on climatic conditions (duration and intensity of rains, duration of dry periods, solar radiation, temperature and humidity, wind conditions), the properties of green roof layers (moisture capacity of the substrate and a drainage layer, the substrate thickness), the type of vegetation, the geometry of a green roof (slope and orientation). Green roofs can be a useful tool for reducing urban storm water runoff. However, in order to ensure high efficiency, it is necessary to use green roof technology with other measures to reduce runoff.

Sign in / Sign up

Export Citation Format

Share Document