Technologies for innovative switchable foils as a retrofit solution for energy-saving windows and glass facades, sub-project: Building simulation, characterisation, life cycle analyses


The FLEX-G 4.0 project is developing innovative switchable electrochromic (EC) films as cost-effective retrofit solution. These should be able to be laminated onto installed windows and contribute to reducing the solar heat gain coefficient (SHGC) of windows and thus the energy demand of buildings. The main objective of the project is to research system designs and manufacturing technologies for large-area EC films, as well as methods for on-site processing and application of the films to windows and facades in existing buildings. Solutions for stand-alone energy supply, suitable switching strategies and sensor technologies for wireless, automated control of the switching state of the films are being researched. Quantification of energy savings potential will be performed on two operational buildings.

Research questions

The project will numerically and empirically address the feasibility and applicability of adhesive films for dynamic shading and the resulting energy savings potential on existing buildings. In addition to the robust and technologically low-threshold implementation as a retrofit solution, the ecological energy impacts are holistically clarified with life-cycle/life-cycle-cost-analyses (LCA/LCC).

Scientific approach and methods

EC films are developed and manufactured by the partners as dynamic shading elements for technologically low-threshold retrofit use in existing buildings. The HFT examines the application and integration into the building operation and accompanies this with monitoring. It prepares building simulations to determine the energy balance and energy saving potential. The calculated potential analyses are compared with measurements and verified by on-site operation. The physical properties of the EC elements are determined in laboratory tests. The ecological impact will be evaluated by means of LCA/LCC.

Targeted results

  • System design/manufacturing technologies for large area EC sheets for on-site application.
  • Process for simple on-site application of the films to windows and glass facades in existing buildings
  • EC films with autonomous energy supply through integrated photovoltaic elements
  • Switching strategies/sensor technologies for wireless, automated control of the EC shading state
  • Calculation/quantification of energy saving potential on two operational buildings
  • Increasing society's awareness of energy-efficient building technology, promoting young scientists
ManagementProf. Dr.-Ing. Jan Cremers
PartnerFraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., tesa SE, Coatema Coating Machinery GmbH, Enerthing GmbH, Landeshauptstadt Dresden
Grant No.03EN1048B
FundingFederal Ministry for Economic Affairs and Climate Action (BMWK)
Programme 7. Energieforschungsprogramm
Call for proposalGebäude und Quartiere



Name & Position E-Mail & Telephone
Architekt, Professor, Dekan+49 711 8926 2620 8/2.01
akademischer Mitarbeiter+49 711 8926 2389 301

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