The new digital banking group BBVA headquarters building in Madrid, designed by architecture firm Herzog & de Meuron, is kept cooler using composite sun panels which are an integral part of the contemporary new building façade. Summer temperatures in Madrid can reach over 300C by midday, so having innovative, environmentally friendly ways to minimise air-conditioning energy usage inside its new head office was high on the agenda for BBVA, with its strong commitment to using renewable energy and buildings with the highest environmental certification.
A total of 1600 sun panels in sizes ranging from 1.5 metres up to 4 metres were supplied and fitted to complete the façade of the new head office building. To meet the required UNE-EN 13501-1 fire standard for the building, the composite panels were vacuum infused using Scott Bader’s matched fire retardant laminate system, comprising of Crestapol 1212 high performance urethane acrylate resin with intumescent in-mould spray Crystic FIREGUARD 75PA (IMS) EXCEL fire protection gelcoat.
All of the panels were produced by Innova Composite, a leading Spanish composite parts manufacturer. Innova has a long established track record in supplying custom designed composite parts for construction infrastructure projects, as well as to other sectors including naval, aviation, automotive, rail and wind energy. The sun panel composite design specification was developed by the external specialist composites consultant, Mr. José Cristos, who worked closely with the Innova Composite production team, as well as technical support personnel from Scott Bader who provided both materials selection and processing advice.
The infused, fire resistant (FR) composite sun panels had to meet all the local building regulations and construction specifications stipulated, overseen by Permasteelisa, the appointed contractor for the new BBVA building construction project. The Permasteelisa Group is a worldwide leading contractor in the engineering, project management, manufacturing and installation of architectural envelopes and interior building systems. In particular for this project, Innova Composite had to ensure that installed sun panels achieved B-s2 d0 ‘low flammability’ fire rating according to UNE-EN 13501-1 European standard for products used in construction, while also meeting all the other design and performance in use criteria; this included long term UV sunlight weathering resistance, critical given the hot Spanish climate, hence the requirement to PU overpaint the intumescent FR gelcoat, which is not UV resistant.
The technical requirements for the sun panels were met by Innova Composite using a custom designed, glass fibre and PET foam core, filled resin sandwich system. The laminate construction is a combination of Crestapol 1212 with 170 parts per hundred of resin (phr) by weight of alumina trihydride (ATH) filler to meet the low flammability fire regulation, with Owens Corning’s Unifilo® CFM (Continuous Filament Mats) glass reinforcement on either side of a thermoplastics PET foam core. This sandwich design format infused with the Crestapol 1212 resin provided the strength, stiffness and weight target for the panels across the size range; while absolute weight was not critical, the overall lower panel weight achieved enabled savings to be made in the specification of the mechanical fixing system, as well as on site during construction as the lighter panels needed less installation time.
For Innova, using Crestapol 1212 infusion and in-mould spray Crystic FIREGUARD 75PA (IMS) EXCEL intumescent FR gelcoat provided the desired combination of production benefits in addition to the mechanical and fire performance properties needed for this external building application. From the production side, there were productivity gains from being able to spray the specialty fire rated intumescent gelcoat and being able to rapidly mould the relatively high number of panels required as a consequence of the very fast ambient temperature cure rate of the ATH filled Crestapol infusion resin. Both of these faster processing benefits helped Innova to be sufficiently price competitive overall to win the contract. Mr. Carles Gil, Technical Director for Innova Composite commented: "We had excellent technical support from Scott Bader in both materials selection of the intumescent FR gelcoat with Crestapol 1212 resin and with help to optimise our infusion process at the high ATH filler level to achieve the EN 13501-1 FR specification to the requested B-s2 d0 level at a competitive part price."
For more information about the Scott Bader Group of companies worldwide and details about the complete range of resins, gelcoats, pigments, bonding pastes and structural adhesive products offered globally for composites applications, go to www.scottbader.com.