Vertical Greenery Systems (VGS) as passive tool for energy savings and acoustic insulation in buildings International Conference on Living Walls and Ecosystem Services 6-8 th July 2015 University of Greenwich, UK PhD candidate Julià Coma Dr. Gabriel Pérez Dr. Luisa F. Cabeza
Contents Introduction Objectives and methodology Energy savings in buildings Acoustic insulation in buildings Conclusions Acknowledgements 2
Introduction Vertical Greenery Systems contribution to Ecosystem Services in the built environment take place at two scales: Building scale Thermal regulation and energy savings Acoustic insulation Materials protection Aesthetics (party walls and back facades) Food production (permaculture) Barcelona. Spain Mora d Ebre. Spain Barcelona Mollerusa. Spain 3
Introduction Vertical Greenery Systems contribution to Ecosystem Services in the built environment take place at two scales: Urban scale Urban environment improvement Heat island effect reduction Relative humidity increment Retention of dust and suspended particles Capture of CO 2 Noise reduction Aesthetics-landscape Increment of biomass Support to biodiversity Profit for the mental health Economics (jobs creation, food production, ) Barcelona. Spain 4
Objectives and Methodology GREA research group objectives for Green Infrastructure: To study the potential of Green Roofs and Vertical Greenery Systems to provide Ecosystem Services in the urban built environment: Passive energy savings Acoustic insulation To design new constructive systems following sustainable construction criteria The methodology is based on to compare identical cubicles, in which the only difference is the constructive system under study (roof, facade, etc.) Experimental installation (21 cubicles). Puigverd de Lleida. Spain 5
Energy savings in buildings The classification of VGS must be considered for energy savings insulation purposes Extensive systems Intensive systems Traditional Green façades Double-skin Modular trellis Wired Mesh Perimeter flowerpots Living walls Panels Geotextile felt Pérez G. et al. Green vertical systems for buildings as passive systems for energy savings. Applied Energy 2011;88:4854-4859 Pérez G. et al. Behaviour of green façades in Mediterranean Continental climate. Energy Conversion and Management 2011;52:1861-1867 6
Energy savings in buildings The classification of VGS must be considered for energy savings insulation purposes Green façades Traditional Double-skin Extensive systems Plant sp. Climbing plant Modular trellis Deciduous/perennial Wired Light support structure Mesh Intensive systems Lleida. Spain Living walls Plant sp. Shrubs Heavy support structure Substrate/geotextil felts Perimeter flowerpots Panels Barcelona. Spain Geotextile felt Lleida. Spain 7
Energy savings in buildings The most influential parameters for energy savings purpose design of VGS are: Pérez G. et al. Vertical Greenery Systems (VGS) for energy saving in buildings: a review. Renewable and Sustainable Energy Reviews (2014) pp. 139-165 8
Energy savings in buildings The accumulated energy savings of three identical cubicles was compared, with the only difference on the façades (east, south and west) Reference cubicle 9
Energy savings in buildings The accumulated energy savings of three identical cubicles was compared, with the only difference on the façades (east, south and west) Reference cubicle Green façade cubicle: Double-skin green façade made by means wire mesh as lightweight support and Boston Ivy (Parthenocissus tricuspidata) as deciduous climber plant 10
Energy savings in buildings The plant growth was appropriate (summer 2015) 11
Energy savings in buildings The accumulated energy savings of three identical cubicles was compared, with the only difference on the façades (east, south and west) Reference cubicle Green façade cubicle Green wall cubicle: Pre-cultivated modular-based green wall system, and perennial bushes Helichrysum stoechas and Rosmarinus officinalis 12
Energy savings in buildings The plant growth was appropriate (summer 2015) 13
Energy savings in buildings The results showed a great shade effect due to the VGS, with interesting reductions on the external surface temperatures (summer 2014) 14
Energy savings in buildings And, energy consumption reductions during the cooling period up to 50% (summer 2014, Indoor set-point 24 ºC) 15
Energy savings in buildings During the heating period, the Green Wall provides a slight thermal insulation (winter 2015, indoor set-point 21 ºC) 16
Acoustic insulation in buildings From previous studies (green belts in roads) it is said that vegetation can provide acoustic insulation by means of three ways: Sound diffraction (reflexion and scattering) by plant elements (trunks, branches and leaves) Sound absorption by vegetation Sound level reduction due to the destructive interference between the direct contribution from the source to the receiver and the reflected sound waves (e.g. from the ground) In this cases vegetation is attributed with some acoustic noise reduction up to 8 db, and occasionally more 17
Acoustic insulation in buildings For VGS, again the systems classification must be considered: green walls vs green facades The main parameters that can influence are: Traditional Green Facades Double-skin Green Facades Green Walls Species used x x x Foliage thickness (or coverage %) x x x Support structure x x Substrate thickness and composition x 18
Acoustic insulation in buildings For the acoustic insulation characterization of our VGS the ISO standards was followed: UNE-EN ISO 140-5 Acoustics. Measurement of sound insulation in buildings and building elements. Part 5: Field measurements of airborne sound insulation of façade elements and façades Standardized Levels Difference (D 2m,nT,w ) is the main parameter, which is the value used to express the acoustic insulation between a room and outdoors 19
Acoustic insulation in buildings Different behaviour was observed 20
Acoustic insulation in buildings Different behaviour was observed Substrate (absorption) 21
Acoustic insulation in buildings Different behaviour was observed Substrate (absorption) Vegetation (diffraction) 22
Energy savings in buildings Conclusions Good performance during cooling period with energy consumption reductions up to 50%, both for Green Façade and for Green Wall (shade effect) Neutral contribution during heating period for Green Façade (deciduous plants) and interesting slight contribution of Green Wall to thermal insulation (substrate layer and perennial shrubs) Acoustic insulation in buildings Some differences between GW and GF were observed The contributions to the acoustic insulation of the substrate layer on the middle frequencies and from the vegetation layer on the high frequencies were confirmed 23
Acknowledgements To the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES) To the Spanish government (ENE2011-28269-C03-01, ENE2011-28269-C03-02, ENE2011-28269-C03-03 and ULLE10-4E-1305) To the Catalan Government for the quality accreditation given to their research group (2014 SGR 123) To Department of Vegetal Production, University of Almería (Almería), the company Buresinnova S.A (Barcelona) and with the City Hall of Puigverd de Lleida Julià Coma wants to thank the Departament d'universitats, Recerca i Societat de la Informació de la Generalitat de Catalunya for her research fellowship To all co-authors of this work 24
Thank you for your attention gperez@diei.udl.cat jcoma@diei.udl.cat 25