The benchmark for efficiency. The Brunkeberg System™ for Installing Lindner unitized Facades
21.01.13 End of 2010 IGS reported about a revolutionary installation innovation: new techniques for safer, faster, wind independent construction: The Brunkeberg System™ for installing Lindner unitized Facades.
Key benefits have been defined as:
- Reduced time and costs for installation
- Easy handling and high quality of prefabricated unitized façade
- Unique recladding system
The Brunkeberg System™ for installing Lindner unitized Facades, a revolutionary concept for installation and demolition of existing façades
It’s time now to have a look what has happened in the meanwhile! But firstly what is Brunkeberg, what is Lindner, what is that revolutionary system:
Brunkeberg, an innovation company from Sweden, is introducing a new system for unitized curtain wall installation, inspired by lean production principles developed by the car manufacturing industry.
Lindner undertakes major worldwide projects in all areas of interior finishes, insulation technology, industrial services and building facades. From pre-planning through to project completion. The Company´s extensive manufacturing capability enables quality to be strictly maintained whilst allowing maximum flexibility to meet individual project requirements. Environmental considerations are fundamental to all Lindner´s business principles. Through partnerships with clients Lindner turns concepts into reality.
This Swedish innovation, combined with Lindner’s experience will achieve radical reduction of the overall installation time required and of the risks of damage and delays, whilst providing a safer method for handling prefabricated façade panels on site.
“For projects unitized curtain walls with highly modular design, we see the potential for 40% reduction of the programme time” says Mathias Farnebo of Brunkeberg Industriutveckling
Lindner Façade now presents the Brunkeberg System™, a new high speed installation system for Lindner’s unitized curtain wall systems.
The Brunkeberg System™ was developed and tested in cooperation with Brunkeberg Industriutveckling AB of Sweden, and is now available for projects where speed and safety of installation are of particular importance.
It all started with the Swedish inventor Henrik Falk radically re-thinking handling of glass. Henrik observed the difficulties in using large elements of glass. Henrik saw untapped potential. To his mind, the entire chain of events was in need of re-engineering to avoid the time wasting and risky multiple handling he had watched.
Henrik had a radical idea to change how glazed panels are manufactured and handled. His partner Mathias Farnebo joined him on an entrepreneurial journey to validate these ideas with the help from various professional disciplines through feasibility studies, rigorous patent research and business evaluation. Once the core concept was structurally resolved and patented, the next step was to analyse and fine-tune the logistic benefits. Brunkeberg contacted Arup in 2009, asking for a review of the concept.
At this point Edith Mueller was director at Arup Façade Engineering in London. Mathias explains that Edith’s first reaction was surprise that somebody from outside the façade industry had come up with this concept. She quickly realised that this might just be what was needed to improve the speed and safety of curtain wall installation.
To bring in more practical façade experience with curtain walling, challenging projects, Design, manufacturing, logistics and installation - Lindner Façade was contacted, and agreed developing mock ups for tests and further investigation.
In June 2010, Brunkeberg successfully completed functionality tests on a full-scale prototype built by the Lindner Group in Germany, reported end of 2010 in IGS. The need to reduce CO2 emissions from buildings is increasing the demand for replacement of older, energy leaking curtain wall facades, yet this is often easier said than done. Not only investment costs but also practicalities prevent building owners from tackling this task. Often the whole building has to be evacuated for several months or even years, because the installation of scaffolding and the creation of isolated internal transport routes is considered too much of a disturbance for existing tenants. This means loss of rental income for the building owner. On other projects, the recladding works progress slower and at higher cost because working hours and transport routes need to be carefully adapted to fit in with the tenants’ business operation.
What is new
To avoid these problems, Brunkeberg and Lindner are currently developing its next generation façade system with components for façade replacement. Meanwhile, the system design continues with details for special building locations being developed. A second and much bigger prototype with lots of technical improvements was built and can be visited and tested in Arnstorf, Bavaria, where Lindner Façade’s headquarter is based, as well as production, research and development departments and a full size test rig. In July 2012 an official test was successfully passed, carried out by IFT Rosenheim.
Summary of test results
- Airtightness: up to 600 Pa which is class A4 according EN 15152.
- Watertightness: up to 600 Pa which is class R7 according EN 12154.
- Resistance to wind load: 1550 Pa serviceability and 2325 Pa safety for wind pressure 2030 Pa serviceability and 3045 Pa safety for wind suction
Conventional unitised curtain wall elements are delivered to site by truck, off loaded and stored on pallets or stillages, then transported to the respective floors where they are stored until they can be installed using glazing robots or monorails systems. For large panels the tower crane is used for lifting and installation, which is unfortunately a fairly slow process. All methods are affected by wind and rain, which often interrupts progress and leads to frustrating pile-ups of materials and delivery vehicles queuing to wait for their turn to have access to the crane for off-loading.
The Brunkeberg System combines standard unitized curtain wall panels with a vertical rail system that becomes an integral part to the final assembled wall. The vertical rails are integrated in the mullions, becoming effectively wind posts of sufficient structural strength to take the loads from very large panels. They further accommodate a temporary horizontal conveyor system which connects directly to the vertically stacked panels as they arrive on the delivery truck. The panels are easily moved along the horizontal conveyor and then lifted vertically by Brunkeberg’s own mini crane directly into their final position.
The system is suitable for both new construction and recladding projects
- Reduced time and costs for installation
- Highly efficient logistics with option for remote off-loading
- Faster installation with a minimum of staff on site
- No interim storage or unnecessary handling
- Installation unaffected by weather conditions
- Façade system advantages
- Large and small prefabricated elements can be easily handled
- Permanent vertical rails to secure cleaning & maintenance equipment, shading and façade lighting
- Enhanced safety for installation personnel
- Unique recladding system
- Wind safe access system
- Minimal disturbance to occupants
Combining the best features
Lindner designs, manufactures and installs a wide range of standard and bespoke unitized façade systems. This new façade concept combines Lindner’s high performance façade systems with a unique engineered installation system to achieve a fully controlled site installation process. It integrates the necessary infrastructure to guide each element securely into position with precision. Elements are installed without interim handling or storage – they are delivered on specially adapted pallets and directly transferred to the installation rails. The system allows even the largest elements to be installed safely and efficiently.
At low or ground level, a horizontal conveyor for the lateral distribution of the panels is temporarily fitted, providing safe and rapid transport without additional handling equipment. These features make the Brunkeberg System™ largely independent from weather conditions, other trades and facilities on site, allowing an uninterrupted flow of the installation process.
The vertical multi-functional profiles feature external channels that enable the secure restraint of unitized façade elements throughout the lifting and positioning process. After completion of the installation, these channels provide the option to act as a guide profile for maintenance access platforms, cradles and a semi-automated façade cleaning system. At roof level, a permanent conveyor can be integrated to provide lateral transfer for any cleaning or access equipment.
This built-in infrastructure enables the installation of solar shading, lighting or vertical fins and signage without penetrating any of the vapor barriers and airtight layers.
Installation Sequence for New Buildings
Install multi-functional profile (wind post)
Special fixing brackets, accommodating all structural loads and tolerances, are installed to the floor slab edge. Floor high multi-functional profiles are then fitted from the floor slabs and supported from the top.
Lift mounting tool
The mounting tools are secured on to the vertical rails of the multi-functional profiles. They are lightweight and easily lifted by the mini-crane. Alternatively the mounting tool can be integrated in the wind post.
Install cladding panel
The element is lifted by the mini-crane while being securely guided within the rails of the multi-functional profiles at all times. They are lifted slightly higher than the level of their final position and then pushed inwards to align with the plane of the finished façade. At floor level, the mounting tool pushes the element into final position. The panel is secured in final position with sliding in glazing beads.
The Brunkeberg System™ also offers a unique replacement system for glazed curtain walls, with tools for safe dismantling and the removal of debris. The re-cladding is executed from the ground floor upwards. Typically the occupants only need to be exposed to the temporary protective wall at two floors at any one time.The system facilitates the installation of new elements as well as the transport of containers. These containers accommodate debris and panels from dismantling the old façade, or can be used for tools or any other components for interior refurbishment that need to be transported up or down.
The demolition of the existing façade can in this way be carried out without traditional scaffolding and external hoist, or needing to break down the components into parts small enough for transport through the interior using internal elevators. Safety and security risks are minimized, as well as the disturbance of building occupants caused by external scaffold.
Conforming to Highest Standards
Like all of Lindner’s project solutions, this new façade concept has been engineered to the highest standards. The mullions and their interaction with the unitized panels in their final position are structurally optimized to minimize the structural depth of the façade elements and minimizes costs.
The complete system was extensively tested on a three story high external rig to rigorously test functionality in a range of climatic conditions and subsequently to verify structural deflections, wind safety, acoustics air and water tightness.
Reduce the cost for maintenance
Cost efficiency during installation shouldn’t be the end of considerations: the permanent guide rails enable the use of a semi-automated façade cleaning system that runs in these channels.
The aim is to enable owners to upgrade the facade when the next generation technology is available. Using the multi-functional profiles paves the way for replacing the façade design without increasing the costs or program for the initial installation. External features like vertical fins or balconies can be integrated without creating cold bridges or complex interfaces. Panels up to six meter width can be designed with interim mullions and transoms or extraordinarily large panes of glass. Openings, glazed and solid infill panels are feasible.
Examples of geometries achievable with straight aligned mullions
The Brunkeberg System™ relies on parallel rails to achieve optimal efficiency. For further design combinations, the system can be combined with any other curtain wall or window system utilizing traditional access and maintenance solutions.
Henrik Falk, Mathias Farnebo, Ludwig Schmid
IGS December 2012 issue.