INFINITE – Industrialized and digitally supported refurbishment solutions in a practical building physics test

The EU project INFINITE is testing innovative, prefabricated fa̤ade systems for energy-efficient building refurbishment in the digital age. The focus is on modular timber frame construction kits with green, thermally active or solar-powered elements. Real measurements show impressive temperature benefits Рespecially for the GREEN fa̤ade with natural evaporative cooling.

Text Dipl.-Ing. Susanne Formanek, GRÃœNSTATTGRAU Forschungs- und Innovations GmbH

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INFINITE – Industrialized and digitally supported refurbishment solutions in practical building physics tests

Figure 1: Mock-up “FlexiLab” © Eurac Research

The EU-funded INFINITE project (no. 958397), initiated as part of the “Horizon 2020” programme, is pursuing the integration of digitalized planning and production processes into the energy-efficient modernization of existing buildings with the concept of “Renovation 4.0”. The focus is on prefabricated all-in-one building systems, which are intended to optimize not only economic criteria but also aspects relevant to building physics such as the thermal envelope, heat storage and moisture protection.

Both life cycle costs (LCC) and life cycle analyses (LCA) were systematically recorded in all phases – from planning to operation.

Five prefabricated, industrially scalable façade systems based on a modular timber frame construction were developed. These are being tested as mock-ups and in existing buildings at various European locations under realistic conditions. The system variants include

• Green, building-physically activated façades (GREEN) with a positive effect on radiation and convection inputs
• Air and energy supply units
• Adaptive window and glazing systems
• Photovoltaic modules integrated into buildings (BIPV)
• Solar thermal systems for heat supply (BIST)

The “FlexiLAB” outdoor laboratory was set up at the Eurac Research site for metrological validation (see Fig. 1). Here, installation costs, operational safety, maintenance requirements and the building physics parameters of the façades were monitored over the long term under real weather conditions. The test period extends from August 2022 to the present day.

A particular focus is on the thermal comparison between the green façade variant (GREEN) and the solar thermal system (BIST). The surface temperature measurements on one of the hottest days of the year (Fig. 2) show differentiated results: A maximum temperature difference of up to 11 °C was recorded on the southern timber frame structure, on the rear side facing the ventilation gap; on the eastern façade up to 10 °C. The rear side of the façade cladding (BC) showed temperature differences of up to 18 °C (south) and 14 °C (east) compared to the reference value.

Figure 2: South- and east-oriented daily temperature changes of the surface temperature on the timber frame structure (WS – Wood structure) and the back of the curtain wall (BC – backside cladding), as well as the outside air temperature (© Eurac Research)

The thermally regulating behavior of the GREEN fa̤ade is particularly striking: during the day, it was constantly below the outside temperature (Temp_EXT), which can be attributed to the positive influence of latent evaporative cooling and reduced solar absorption by the vegetation. At night, on the other hand, there was an opposite effect Рwith higher surface temperatures compared to the BIST fa̤ade, which indicates reduced heat radiation from the greenery.

The renovation kits developed in INFINITE will next be used in pilot projects in France, Italy and Slovenia. The aim is to monitor and further develop the building physics performance in detail over the course of a year under real conditions of use.