smart façade - energy potential of adaptive façade systems
Starting point / motivation
The physical properties of building façades in our cities at present are not able to adapt to changing conditions in a significant manner.
This applies to both the ever changing external conditions such as climate, noise, air quality and light and the fluctuating demands and needs of building occupants on the internal side of the façade interface.
Their specific properties in terms of thermal conductivity, solar heat gain transmission, light transmittance, porosity etc. are static and remain essentially constant although the requirements for an energy efficient building skin differ significantly under the widely varying climatic conditions at different times of the day and year.
Existing responsive façades are limited to one-dimensional approaches such as automated shading systems or solar energy storage and use of special wall systems.
The work proposed here will form the scientific basis for the development of a completely new approach to façade design by precisely determining the energy potential offered by the approach under various assumptions as well as useful insight into successful strategies for the development of suitable components.
Contents and goals
The research project "smart façade" examines the energetic potential and possibilities, both in qualitative and quantitative terms, of future-oriented "smart" adaptive façades, façades that are able to react to variable climatic conditions and user behavior by changing their physical properties. The proposed "smart" façade would employ data from weather forecasts and anticipated user behavior, based on artificial intelligence systems, as well as current requirements and constraints, in order to assume the optimal physical characteristics required to achieve maximum energy efficiency and comfort.
The aim of the research is to assess the energy potential of smart façades, which are able to vary physical parameters for
- thermal insulation (U-value),
- energy transmittance (g-value),
- light transmission (τ-value),
- heat storage (c-value),
- air tightness (n-value) and
- moisture transmittance (F-value),
in order to adapt to changing internal and external conditions.
A new and innovative, dynamic simulation model, which is developed specifically for this project, provides significant insight into the potential of adaptive facade systems, which allow varying building physics performance, as well as the synergetic potential of combined parameters. The study serves as a basis for the development and implementation of new building envelopes and suitable automatic control systems.
The module-based software package "Grasshopper" with add-ons such as "Honeybee" and "Ladybug", which is based on the CAD software "Rhinoceros", enables the implementation of calculation engines such as "Energy Plus" or "Radiance".
The surface of "Grasshopper" acts as an interface between these engines and allows direct algorithmic calculation methods as well as the implementation of "Matlab 18". These flexible features and with that, the almost unlimited possibilities in energy analysis, make it an ideal tool for the creation of the complex and unconventional simulation model required for this research project.
This project leads to insights into the energy potential of location-specific optimized, adaptive façades and serves as a valuable basis for the development of new materials and façade typologies for different climates and building uses.
The simulation model serves as the basis for controlling future, real, adaptive façade systems that will be developed with partners from science and industry in stage two of the research project and will be realized in the third stage.
Graz University of Technology, Institute for Buildings and Energy