Researchers from the Polytechnic University of Madrid (UPM) have built a roof covered with plants and a watering system that will optimise the consumption of a building’s heating and cooling systems thanks to its insulation. It is a third-generation ecological roof, characterised by its sustainability and the use of indigenous plant species.
“The importance of the roofs”, explained Francisco Javier Neila, Professor at the UPM and co-author of the study, to SINC, “is that each geographical area requires the structures and plant species that work best”. In this case, the researchers divided the roof of an experimental building in Colmenar Viejo (Madrid) into 20 modules, and carried out a test with different supports and regional plants based on three factors: the plant growing at a good speed, the density of the biomass perfectly covering the roof and the result being visually attractive.
Indigenous species work better
In winter and summer conditions, the best performing roof has an 8 cm tank that collects rainwater and offers an even irrigation system.
Plants such as sedum (Sedum praealtum) or aptenia (Aptenia cordifolia) provide the best insulation “because they have a thick leaf and are resistant to frosts and heat”, indicated Neila. But each location where an ecological roof is installed will have its own catalogue of plants, starting with indigenous plants “because in its habitat, the plant performs better”.
The researchers also considered covering the roofs with an effective plant and decorating it with another prettier one to fulfil both requirements, but the result is difficult ,“since when a single space is shared by two species, the stronger one will predominate”, Neila explained.
There are a series of superimposed layers under the groundcover. The first is a very light special substrate which helps to drain rainwater quickly so the plant does not drown. Here, the best solution is pine bark crushed and mixed with sewage sludge.
The substrate lies on porous concrete which acts as a sieve for excess water that will end up in the tank, the capacity of which is controlled by raised floor systems similar to those that support the raised floor of an office. The water contained rises up to the roof through capillary action and enables even irrigation. Just before the building’s floor framing, the roof consists of a waterproof sheet which prevents leaks.
Between each layer an extruded polystyrene sheet is inserted which, according to the roof model, can be situated under the porous concrete or beneath the tank. Each layer also includes a sensor that measures temperature and humidity variables which can be compared with data collected by an adjoining weather station for checking any change caused by the roof during the four seasons of the year.
The researchers have also left various modules without an ecological roof to clearly demonstrate its effectiveness. “Roof areas with plants optimise better the heating and cooling of a building than a normal structure, regardless of how well insulated it is”, the expert commented to SINC.
The design of ecological roofs responds to the challenge of merging urban and rural lifestyles and is being developed in countries such as Germany, Switzerland, the USA and South Africa. Ecological roofs reduce pollution in cities, absorb lead and other organic components. “A forest would be less contaminated with the same intensity of urban pollution", said Neila.
These roofs will help to reduce the temperature of cities, which today are a kind of urban heat island. Scientists have also estimated that acoustic contamination would be reduced to three decibels, thanks to plant absorption.
Groundcover is therefore becoming a new type of building material but development prospects are not positive due to its high price. Neila cites Germany, “where the situation is being resolved with tax benefits, council taxes, increase in suitability for building, which means it does not cost developers so much to invest in this option”.
SINC Team | alfa
Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology