ACT Facade

Combining Façade And Ventilation Technology For Energy Efficiency And Comfort



Due to material and technological advancement during the last century, transparency has become a prominent trend in contemporary architecture. However, the fully glazed facades have posted an imminent challenge to the building’s energy consumption while imposing probable thermal discomfort and glare issues. In recent years conventional strategies such as double skin façades with integrated solar control strategies have been developed. Nevertheless, the overall performance is proven to be unsatisfactory. As a solution, the Active Cavity Transition (ACT) Facade has been introduced as a further development of the conventional double skin façade. ACT Facade is an adaptive façade system which is comprised of an integration between typical façade components such as insulated external glazing, an internal screen, and the building’s mechanical ventilation system. It acts as a sun-shading device which prevents direct sunlight and glare, while creating an enclosed cavity condition serving as an air-exhaust corridor to trap heat before it enters the interior space. The system offers an adaptive condition where heat gains and view towards the outside can be controlled. The ACT Facade shows considerably higher performance in comparison to a conventional interior glare protection screen. Due to the simplicity of its system built up, the ACT Facade requires a relatively low number of materials in production, so it produces less environmental impact. Furthermore, the ACT Facade requires less space for installation compared to standard double skin facades, which allows rentable floor area to be maximized. Results from tests, simulations and realized projects described in the paper have shown a potential for the ACT Facade to be optimized and adapted to meet specific demands of individual projects as well as locations and climate conditions.


Photo of Paul-Rouven Denz

Paul-Rouven Denz

Priedemann Facade-Lab GmbH

Photo of Daniel Arztmann

Daniel Arztmann

Dipl.-Ing., M.Eng., EFN, FTI Professor for Façade Construction, Technische Hochschule Ostwestfalen Lippe (TH-OWL) Head of Building Physics

Schüco International KG

Photo of Natchai Suwannapruk

Natchai Suwannapruk

Priedemann Facade-Lab GmbH



As a result of the material and technological advancement during the last century, the transparency trends in architecture are constantly being redefined. Driven by the radical development, we have witnessed the emergence of new trends over the last decade. (Brzezicki 2016). As higher level of transparency can be achieved, contemporary office buildings are built as fully glazed high-rise buildings to comply with the client’s wishes or the design intent in creating a maximal visual connection with the environment or emphasizing the corporate identity of the companies. However, in comparison to the traditional façade system, fully glazed façade tends to have higher energy consumption for cooling and heating. It also increases the probability of thermal discomfort and glare issues. (Eriksson and Blomsterberg 2009)

In response to these challenges, sun-shading devices and higher ratio of opaque façade areas are commonly implemented. However, they possess a number of limitations, especially in high rise buildings. As external sun-shading devices have high maintenance costs and are vulnerable to strong wind (Meijs and Knaack 2009), higher opaque façade areas contradict with the transparent design intension. In recent years several façade solutions have been explored to overcome these challenges. An increased interest in double skin façade’s application with integrated strategies such as energy saving, preheating of ventilation air, night cooling, etc. becomes apparent (Eriksson and Blomsterberg 2009). Nevertheless, several studies have shown an unsatisfactory overall performance, as the criteria for visual comfort, thermal comfort and maximal view has led to a contradicting design strategy (Wienold, et al. 2019).

To accommodate to the thermal and visual comfort of the users, the ACT (Active Cavity Transition) Facade was developed. Based on an exhaust-air façade system, which utilizes the façade cavities in combination with the building’s ventilation system to regulate the indoor climate (Herzog, Roland and Werner 2004), ACT Facade presents itself as a development double skin façade approaches activating cavity properties within the façade built-up. Thus, evolving from a constructional double layered façade, over the concept of exhaust air façade to ACT Facade where the cavity is created solely by adding an internal textile blind to an external glazing to create such cavity (Denz and Tyurkay 2019). This paper focuses on the recent development of the ACT Facade system. It examines the design parameters and their effects on the implementation of the ACT Facade based on case studies of built projects. The performances of the ACT Facade are empirically evaluated through the means of testing and software simulation and the results are qualitatively discussed in relation to conventional façade systems.


ACT Facade is an adaptive façade system which is comprised of an integration between typical façade components such as insulated external glazing, an internal screen, and the building’s mechanical ventilation

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Similarly, with a conventional double skin façade, the geometry of the cavity, size and positioning of air inlets and outlets are crucial design parameters for the ACT Facade; as they

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The test at VERU provides an extensive overview of the operating principle and performance of ACT Facade for office buildings. The results have shown that with a combination of constructional

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Conclusion and Future Work

Results from tests, simulations, and monitoring as well as feedbacks form users of realized projects provide tangible evidence that the integrated system of ACT Facade has the potential to provide

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The authors would like to thank Schüco International KG, WAREMA Renkhoff SE, Transsolar KlimaEngineering and Priedemann Facade Experts as well as Fraunhofer IBP and Fraunhofer ISE for their support in the testing, optimization and realization of ACT Facade. The authors furthermore gratefully acknowledge the support within the Synergiefassaden research project for further investigation of the ACT Facade concept and its funding by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) based on a decision by the German Bundestag.

Rights and Permissions

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