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Today, green roofs are a building system which provides interesting benefits over traditional roof solutions. The most important advantages are the reduction of surface runoff in cities, improvement of the urban climate, biodiversity support, improvement of the durability of roofing materials, and, especially, energy savings. This paper has the aim of studying the performance of green roofs as a passive system for energy savings, within a wider objective of seeking constructive solutions suitable for sustainable and environmentally friendly architecture. This idea is tested at an experimental installation available at the University of Lleida, with several cubicles testing the energy performance of different construction solutions. This work raises the possibility of using recycled rubber from tires as a drainage layer in green roofs, substituting the porous stone materials currently used (such as expanded clay, expanded shale, pumice, and natural puzolana). This solution would reduce the consumption of these natural materials, which also require large amounts of energy in its transformation process to obtain their properties. Moreover it would provide a solution to the problem of waste rubber from the tires, known as rubber crumbs. Since the purpose of the drainage layer is the optimum balance between air and water in the green roof system, first the ability for draining of recycled rubber granules was studied and was compared with the offered by stone materials. The new solution using rubber crumbs is also studied to test if it would keep the same insulating properties that the green roof with stone materials presented in previous studies. Early results show that this extensive green roof system can be a good passive energy savings tool in Continental Mediterranean climate in summer, and that rubber crumbs can be an interesting substitute for stone materials used as drainage layer in this type of green roofs.

In the last few years an increasing attention has been paid to efficient energy construction systems in the building sector. Although in this contest extensive green roofs are reported to be very effective and sustainable systems, the fact that the main agents of this systems are living organisms have generated doubts, especially in locations where the development of plants and vegetation can be greatly affected by climate. This study aims to investigate the thermal performances of a 2000 m2 18 particular proprietary extensive green roof system, located on the city of Lleida (Spain), classified as Dry Mediterranean Continental climate. First, plant cover and floristic composition analysis were carried out to evaluate the dynamic of the plant layer over the surface. Then, according to the result of the botanic analysis, summer and winter study in terms of spatial and temporal factors were conducted focusing on the substrate layer, evapotranspiration effect and comparing the different behaviour of the system in low 10%) and high (80%) plant cover conditions. In this extensive green roof, the results showed temporal and spatial changes in floristic composition, with a stable cover of Sedum sp between 20 to 40 %, and a peak of colonizing species in spring and early summer. The increase in vegetation cover appears to have few effects on the above nearby roof environment because of the low moisture level in the substrate layer so that the cooling effect provided by the evapotranspiration does not take place. In addition, the increased presence of vegetation canopy may induce a limitation in substrate night cooling whereas serves as good shield for solar radiation during the day. Finally, the study also reveals the importance of the spatial factor in extensive green roofs, which can lead to not negligible variations on the thermal performance, as well as the floristic composition. The work was partially funded by the Spanish Government (ENE2011-28269-C03-02 and ENE2011-28269-C03-03), in collaboration with Gardeny Science and Technology Park in Lleida (Spain). The authors would like to thank the architect Josep Maria Puigdemasa his provision of information about the renovation project. On the other hand the authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). Julià Coma wants to thank the Departament d'Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya for his research fellowship. Furthermore the research was supported by the Italian Ministry of Education, University and Research MIUR.

2013 ISES Solar World Congress The new technologies of plants integration on buildings offer new possibilities from the sustainable construction point of view, especially in energy savings. In previous studies the great capacity of double-skin green facade or green screen to intercept solar radiation was confirmed, observing differences up to 18 °C in surface temperatures between sunny and shade areas on the wall of the building. The experiment presented here consists of two identical house-like cubicles (3 x 3 x 3 m) located in Puigverd de Lleida, Spain. The only difference between the two cubicles is the double-skin green facade installed in one of them. In a first step only the South wall was covered by a provisional green facade. As the results from first experiment were positive with interesting low electrical energy consumptions when only the 50% of the South wall was covered by plants, a new stable green facade was built covering the South, East and West facades by a deciduous specie well adapted to the Mediterranean Continental climate. With this study the confirmation of the good operation of green facades made with deciduous species as passive system for energy savings in buildings is expected to be characterized. The work was partially funded by the Spanish government (project ENE2011-28269-C03-02 and ULLE10-4E-1305). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2009 SGR 534), and to City Hall of Puigverd de Lleida.

Abstract It is well known that it is necessary to insulate the buildings to decrease the thermal demand and to decrease the use of heating and cooling. Due to the high cost of fossil fuels and to the necessity to reduce CO 2 emissions, and also due to the new building regulations more attention is paid to the insulation of buildings. Different insulation materials are available in the market. Usually, they are compared by their thermal conductivity and with theoretical calculations, but there are no experimental comparisons available, where the behavior of such insulation materials in a building is compared over time. This is why the authors started a comparison of three typical insulation materials, polyurethane, polystyrene, and mineral wool. For this purpose, four house-like cubicles were constructed (with a size of 2.4 m × 2.4 m × 2.4 m) and their thermal performance throughout the time was measured. The cubicles were built under a conventional Mediterranean construction system, differing only in the insulation material used. During 2008 and the first months of 2009 the performance of these cubicles was evaluated, and the results are presented in this paper.

Abstract This work presents the results of an experimental set-up to test phase change materials with two typical construction materials (conventional and alveolar brick) for Mediterranean construction in real conditions. Several cubicles were constructed and their thermal performance throughout the time was measured. For each construction material, macroencapsulated PCM is added in one cubicle (RT-27 and SP-25 A8). The cubicles have a domestic heat pump as a cooling system and the energy consumption is registered to determine the energy savings achieved. The free-floating experiments show that the PCM can reduce the peak temperatures up to 1 °C and smooth out the daily fluctuations. Moreover, in summer 2008 the electrical energy consumption was reduced in the PCM cubicles about 15%. These energy savings resulted in a reduction of the CO2 emissions about 1–1.5 kg/year/m2.

Vertical Greenery Systems (VGS) are promising contemporary Green Infrastructure which contribute to the provision of several ecosystem services both at building and urban scales. Among others, the building acoustic insulation and the urban noise reduction could be considered. Traditionally vegetation has been used to acoustically insulate urban areas, especially from the traffic noise. Now, with the introduction of vegetation in buildings, through the VGS, it is necessary to provide experimental data on its operation as acoustic insulation tool in the built environment. In this study the acoustic insulation capacity of two VGS was conducted through in situ measurements according to the UNE-EN ISO 140-5 standard. From the results, it was observed that a thin layer of vegetation (20–30 cm) was able to provide an increase in the sound insulation of 1 dB for traffic noise (in both cases, Green Wall and Green Facade), and an insulation increase between 2 dB (Green Wall) and 3 dB (Green Facade) for a pink noise. In addition to the vegetation contribution to sound insulation, the influence of other factors such as the mass factor (thickness, density and composition of the substrate layer) and type of modular unit of cultivation, the impenetrability (sealing joints between modules) and structural insulation (support structure) must be taken into account for further studies. The work was partially funded by the Spanish government (ENE2011-28269-C03-02, and ULLE10-4E-1305), in collaboration with the company Buresinnova S.A (C/ Saragossa, 95 Entsol 3ª, 08006 BARCELONA). Moreover, the research leading to these results has received funding from the Eurpean Commission Seventh Framework Programm (FP/2007–2013) under Grant agreement No. PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 657466 (INPATH-TES). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123), to the City Hall of Puigverd de Lleida, and to Gestión Medioambiental de Neumáticos S.L. and Flag Soprema S.L.U. companies. Alvaro de Gracia would like to thank Education Ministry of Chile for Grant PMI ANT1201. Finally, Julià Coma wants to thank the Departament d’Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya for his research fellowship.

To “green” building envelopes is currently one of the most promising ways to provide energy savings in buildings and to contribute to the urban heat island effect mitigation. The shadow effect supplied by plants is the most significant parameter for this purpose. One way to characterize the potential shadow effect of greenery is to calculate the facade foliar density by means of the leaf area index (LAI). As LAI is commonly used in horizontal crops, their use in vertical greenery systems (VGS) has generated dispersion and uncertainty in previous studies both in terms of methodologies and results obtained. In addition, a lack of data relating to the influence of the facade orientation in the final contribution of vertical greenery to the energy savings has been observed in previous studies. This study aims at establishing a common and easy way to measure LAI and to lick it to the energy savings provided by VGS. Moreover, the energy savings achieved as well as the influence of facade orientation on the final thermal behaviour of two different VGS, a double-skin green facade and a green wall, was studied. From the results, it can be stated that the most simple and quick procedure to measure LAI in order to characterize the foliar density of VGS is the indirect method based on the amount of light transmitted through the green screen. From the experimental tests interesting energy savings were obtained (up to 34% for Boston Ivy pant specie with a LAI of 3.5–4, during summer period under Mediterranean continental climate). Moreover, the dependence on facade orientation was confirmed with representative contribution over the whole energy savings from East and West orientation. The work partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and ULLE10-4E-1305). The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123) and to the city hall of Puigverd de Lleida. This projects has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under grant agreement No. PIRSES-GA-2013-610692 (INNOSTORAGE) and from European Union’s Horizon 2020 research and innovation programme under grant agreement No. 657466 (INPATH-TES). Julià Coma would like to thank the Departament d’Universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya for his research fellowship.