Understanding ZERAF Façade Technology: Technical Insights and Possible Variations

ZERAF (ZERo-carbon building enabler Adaptive opaque Facade technology) is a groundbreaking facade concept designed to drastically reduce the carbon footprint of the EU building stock. The technology transforms traditional static thermal barriers into dynamic thermal modulators, significantly enhancing energy efficiency in buildings.

How ZERAF Works

ZERAF technology can adapt the thermal behavior of opaque facades, shifting, when needed, from being highly thermal insulated facade to a thermal exchanger. It achieves this by autonomously and reversibly adapting the configuration of its three key components: the kinetic cladding, the adaptive air cavity and the Active Insulation component.

1. Kinetic Cladding: This outer layer can open and close to modulate the amount of solar radiation reaching the façade surface in contact with the insulation layer. When closed, it reflects a significant portion of incident solar radiation, minimizing heat gains. When open, it allows solar radiation to reach the Active Insulation, which absorbs heat and increases its temperature. The movement of the kinetic cladding is controlled by a novel actuator made of Shape Memory Alloys, which can be deformed and recovers its original shape after heating.
2. Adaptive air cavity:  the opening degree of the kinetic cladding also modulates the natural convective effects of the air cavity created, thus increasing or decreasing energy loses depending on its position.
3. Active Insulation: Made of bio-polyurethane, this component features a channel geometry on its inner and outer surfaces, forming a closed-loop system when covered with a panel. When air is forced to flow through these channels, heat is transferred from one side to the other. In the absence of airflow, it acts as regular insulation. For example, on a sunny winter day, the kinetic cladding opens, and the outer layer of Active Insulation warms up. Airflow through the channels transfers this heat to the inner layer, reducing the energy needed to heat the indoor environment.

A control logic system determines the optimal position for the kinetic cladding and whether air should flow through the Active Insulation based on environmental and indoor conditions, as well as user needs for thermal comfort. This allows ZERAF to control heat transfer through the opaque parts of building envelopes, reducing heating and cooling energy demand while ensuring comfortable indoor conditions.

ZERAF’s innovative use of materials, such as bio-polyurethane and Shape Memory Alloys, simplifies the technology while enhancing its adaptive capabilities. This combination of materials and adaptive configurations makes ZERAF a standout solution in the market, poised to revolutionize energy efficiency in the construction industry.

Variations of ZERAF Technology

ZERAF is a versatile solution that can be adapted to various building types and design requirements (patent pending):

1. Kinetic Cladding Designs: The kinetic cladding can be designed using different approaches, such as louvers or rollers, to fit the aesthetic and functional needs of different buildings.
2. Space Constraints: If space is limited in the inner part of opaque facades, the inner channel geometry of the closed-loop Active Insulation can be placed in the ceiling or inner partitions.
3. Integration with Existing Buildings: ZERAF can be seamlessly integrated into existing buildings with a certain level of insulation, bypassing the existing insulation.
4. Integration in roofs: with the outer layer substituted by a green-roof layer or photovoltaic panels to generate renewable energy onsite.

Simulation models play a crucial role in identifying potential applications and markets for ZERAF technology. By validating these models with experimental tests, researchers can predict how ZERAF will perform in various building types and climates. This helps in pinpointing the most promising markets and applications for the technology, ensuring that ZERAF reaches its full potential when it hits the market. These models not only guide the development process but also provide valuable insights for architects and designers, making it easier to integrate ZERAF into their projects.

Stay tuned to discover how our research activities are progressing and how interdisciplinary research is key to the success of the ZERAF project!