A Case Study by ARaymond
Innovating thermal building facades for sustainability
Although there are several contributors to climate change, the combustion of fossil fuels ranks at the top in terms of global warming. It’s easy to point outwards to the power and industrial plants or the cargo ships and planes for their high levels of carbon dioxide emission, and there is certainly truth to this.
However, the homes and buildings where we live and work are also a part of the problem — and, particularly, if they were constructed more than a decade ago. One look at your heating bill during the winter months, and you might agree. Poor insulation and weatherizing can lead to high energy bills for building owners — and the climate.
Insulation material can significantly reduce heat loss or unwanted heat gain, thereby reducing the use of fossil fuels or electricity necessary to live comfortably. But
for most infrastructure, this requires renovations or new construction. In Europe, this has been a slow process and it’s expected that about half of the existing buildings will still be poorly insulated by 2050, which does little to meet climate-change objectives.
What’s more: new retrofitting techniques have also been slow to hit the market. This is partially due to costs, as well as poor quality or installation.
Concerned, a small consortium in France connected over this issue for nearly a decade with the end goal of innovating a new, environmentally friendly retrofit
solution for buildings that would decrease energy consumption.
Today, these partners include CEA Tech, a French government R&D organization; Vicat, a concrete manufacturer in France, and ARaymond, a global company
providing innovative and customized fastening and assembly solutions. The CONIPHER project was made possible by the contribution of a European Union (EU) program, LIFE, which is the EU’s funding instrument for the environment and climate action.
“In 2015, we launched what we call the CONIPHER project, with the goal of developing a new solution, that insulates and attaches to the outside facade or walls
of existing buildings,” explains Stéphane Gelibert – Business Development Manager for Building with ARaymond.
“At the same time, there’s an option to generate renewable energy with the inclusion of solar panels.”
The CONIPHER project takes a “life-cycle approach,” which includes retrofit thermal cladding technology, component recyclability, and the renewable energy option. The aim has been to make renovations more popular and increase their climate-positive impact.
“Indeed, the main project objectives have been to reduce energy costs and consumption for existing buildings by creating a high-quality thermal retrofit panel
that’s quick and simple to install,” says Gelibert. “It was important for us to ensure an easily adaptable system.”
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For ARaymond’s part in the project, this meant developing a fastener assembly for the concrete frame, which reliably holds the insulation and attaches to the building’s facade. As the installation of building retrofits can be complicated, the aim was for a single, quick, and cost-effective operation that does not require advanced assembly skills.
THE CHALLENGES
To devise the first “plug-n-play” panel that could easily attach to existing building walls, maintain insulation and connections (mechanical and electrical), withstand temperature variations or weather events, and potentially hold solar panels, took a few trials.
“When we started to work on this project, we had to develop a few different proofs-of-concepts,” shares Gelibert. “One architect who worked with us said that about 50% of renovations use or propose a solution that is not of very good quality and, if we follow the traditional retrofit building methods, 50% of them in Europe would still be poorly insulated. This does little to meet climate change objectives so, we were determined to design a durable concept. We wanted to guarantee a system that could last 25 years and succeed in our 2050 climate objectives, which is one reason for the concrete facade.”
The CONIPHER project team since created what it has termed, the Concrete Insulation Photovoltaic Envelop for Deep Renovation or CONIPHER. This is a wall-finishing system, suitable for nearly any building renovation, with the option of solar PV.
“We now have a good one that we are proud of, which includes a concrete frame and that offers quality, efficient time-savings related to installation, and overall sustainability,” he adds.
However, this was no simple feat. To develop a system that withstands a couple of decades regardless of the elements takes research, planning, and testing.
“There were some challenges. For example, when it comes to insulation and buildings, there are often problems with moisture and thermal bridging, and we wanted to improve what options were already on the market,” says Gelibert. Thermal bridging refers to the movement of heat across an object that’s more conductive than the materials around it, and can be a source of energy loss in buildings.
ARaymond’s task was also challenging as its engineers had to design the fastening interfaces that hold the concrete frame, which incorporates the insulation, to
the building’s load-bearing wall.
“We decided to break some of the rules and use materials that are not traditionally employed in building or construction projects — such as plastics,” he says. “We have completed quite a lot of research in the automotive sector on the performance of high-modular plastics, and so we referred to this research for this building project.”
Although most fasteners are produced from metal, plastic materials are exceptionally strong, yet flexible, to allow for the ideal shape and form. Plastics also fail to rust, which is typically a big plus. On the CONIPHER project we have chosen plastic for its ability to cut thermal bridges. The plastic used for the spacer was specifically selected for its anti-creeping effect, so its very rigid.
“One of the plastic spacers that we designed to fit between the façade and the building wall easily met the seismic test,” says Olivier Bizzini, Project Manager
with ARaymond. “It’s also enclosed to ensure it’s fully fireproof and safe to use.”
This is critical to meet building code standards, especially if solar is also installed. If solar PV is added to a project, strong stainless-steel brackets are used to hold the panels in place.
How the installation works:
• Panels are mechanically lifted onto the building facade
• Next, holes are drilled through the panels to to the façade
• The holes are cleaned before a chemicalsealing injection is added in each one
• The fasteners are then positioned and easily tightened, using a hand wrench
• Next, a thermal-breaker plug is added with a few taps of a hammer
Thanks to the “plug-n-play” prefab technology approach, the retrofit thermal upgrade is simple and allows for component recyclability. In fact, one of the project
goals was to limit waste at the construction site to 5% of the total mass.
What’s more: “If a facade is typically insulated in 1h40 per-square-meter, the CONIPHER panel significantly reduces this installation time,” says Bizzini. “Tests are ongoing at the moment for the exact number, but this is a breakthrough installation time.”
THE RESULTS
In 2018, ARaymond and Vicat collaborated with the Institut National de l’Energie Solaire (INES) to develop cladding panels that combined with the concrete plate and attachment, including a mineral wool insulation layer.
According to Vicat, “Eight prototypes were produced and installed on an instrumented façade of FACT, tool located on the INES experimental platform.
The result: In winter, the CONIPHER system offered a heating energy economy of 90%.
“This result is obtained, thanks to an anchoring system designed to reduce thermal bridges in comparison to conventional thermal retrofitting techniques,” added
Vicat. “. These results confirm the choice of technology (bifacial cells) and the potential of façade integrated photovoltaics.”
“Bear in mind that this is a breakthrough innovation that’s not relying on any standard parts,” shares Bizzini. “We’re integrating the panel system to a building, using a simplified process that’s strong, yet easy to install and effective. We want this to become a global option for any existing building facade.”
KEY COMMITMENTS
In an effort to offer a cost-effective, sustainable thermal retrofit to building owners, the CONIPHER team committed to:
• Ensuring a system return on investment in under 10 years
• Ensuring easy installation and applicability to a wide range of buildings. Installation requires only one or two trades and 50% less time than typical panels
• Reaching high thermal resistivity - with an R value of the envelope of 5 m²
• Reaching 60% of electrical self-consumption within one year using smart PV integration into east, west, and south facades (compared to 30%, which is average for most solar PV roof installations)
• Limiting waste at the construction site to 5% of total mass
• Facilitating the implementation of European climate and environmental legislation