LightFromFacade - Optimized Day- and Artificial Lighting by Facades
The façade, as an interface between the outdoor and indoor climates, is a decisive factor for energy consumption of a building. It controls daylighting, influx of solar energy and heat flow. Apart from energy, the façade is also a decisive factor for visual and thermal comfort. Light is the most important information medium (visual perception) and demands on the illumination of work places are becoming more prevalent. When energy for heating demand is reduced due to daylight and artificial lighting in winter, the need for cooling is increased in summer as the electricity for illumination must be re-cooled by electricity.
Multi-functional pre-fabricated façade elements open up possibilities for the building industry, in that they are able to operate faster and in a more flexible manner using quality controlled building components. The more technical functions that the façade can fulfil, therefore results in less complexity for the interior work, which is especially decisive in the area of renovation.
The K-Project, “Multifunctional Plug&Play Façade (MPPF)”, which started in April 2008 and is aided by the COMET Program, deals with the development of such façade elements. During the course of the work it has however shown that the aspect of daylight utilization and artificial lighting out of the façade, is not sufficiently taken into account from a personal or a financial point of view. This important aspect concerning comfort and the energy requirements for heating and cooling could thus be dealt with more intensively. Therefore, this project represents a „Side Project” in the non-K area of MPPF.
Example of innovative facade: ZVK Wiesbaden (Arch. Herzog & Partner)
© Bartenbach LichtLabor
The aim of the project was the development of energy-based optimized concepts for the provision of daylight and artificial lighting from the facades for the interior spatial areas. For this purpose, the luminaires for artificial lighting should possibly be already integrated into the pre-fabricated façade. These façade concepts were designed to yield sufficient daylighting as well as artificial lighting especially in the depth of the room, while concurrently providing high visual comfort (e.g. without glare). Concerning daylighting not only standard components such as glazing or shading elements, but also daylight deflection systems were important, for artificial lighting diverse luminaire systems (direct/indirect or indirect/indirect) played a decisive role.
With the involvement of a façade construction company, integration of the artificial lighting and the daylight elements (lighting, sun-screening and glare protection) into the façade elements were ensured.
Following extensive research in terms of a market analysis of daylighting systems and combined façade systems, of scientific work, and of relevant patents, reference rooms with energy efficient and lighting optimized concepts including controls have been defined. The integrated façade systems were evaluated in respect of lighting quality, overall energy requirements of the rooms for heating, cooling and electricity. To do so a combined method for thermal and light simulations was developed that allows for an integrated evaluation of the interior space for each timestep of the full annual simulation.
The results are a basis for further façade developments and will be introduced into workshops, training courses and also into educational courses of the participating university institutions (University of Innsbruck, Lichtakademie Bartenbach).
Within a follow-up project the project consortium wants to define characteristics specifying the properties of a daylighting system concerning its thermal and light behaviour to enable a uniform evaluation of such complex façade systems. Additionally, the approach of a coupled light and thermal simulation from this project “LightFromFaçade” shall be extended to a tool to be used by light-, building- or façade-planners. The physical models used to represent the daylighting systems are to be further developed and the resulting tool should be easy to use for the user.
Bartenbach LichtLabor GmbH
Mag. Christian Knoflach, DI Dr. David Geisler-Moroder
Bartenbach LichtLabor GmbH
Project or cooperation partner
- Prof. DI Dr. Wolfgang Streicher, DI Daniel Neyer, DI Martin Hauer
Universität Innsbruck, AB Energieeffizientes Bauen – Gebäudetechnik und erneuerbare Energien
- DI Dr. Mario J. Müller
FIBAG (Hans Höllwart – Forschungszentrum für integrales Bauwesen AG)
- Ing. Johann Gerstmann
Ingenieurbüro Johann Gerstmann