KEYWORDS: Compound parabolic concentrators, Solar energy, Light sources and illumination, Systems modeling, Prototyping, Sun, System integration, Data modeling, Diffusers, Solar energy systems
The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system
oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for
lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with
sustainable energy.
The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the
false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light
extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose.
The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work
hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this
study are the result of simulation models and have been confirmed by a physical scaled prototype.
ADASY's main advantages over regular illumination systems are:
-Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed.
- No energy consumption; solar light continue working even if there has been a power outage.
- High quality of light: the colour rendering of light is very high
- Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity.
- Health benefits
Due to antiquated technologies (calculation methods, regulations, lighting and luminaire concepts, production techniques) current outdoor lighting causes a lot of problems like light pollution, glare, energy waste etc.
New types of luminaires, and in consequence new outdoor lighting concepts, can be created by combining advanced calculation methods for optical surfaces with recent production technologies and novel light sources such as short arc metal halide lamps. Light emitted from this small Etendue light sources can precisely be redirected by 3D-curved surfaces manufactured with injection molding, milling and aluminium metallization. The required optical design may use techniques like complex surface calculations and 3D-Tailoring.
An innovative concept based on the latest findings in visual perception research is to focus the light of such short arc light sources onto a facetted secondary mirror which provides the desired illuminance distribution on a facade or a public place. These systems are designed to fulfill lighting requirements as well as providing visual comfort. Thus lamps with improved color rendering, luminous efficacy and increased lifetime are used and glare is minimized by splitting the reflector into many facets (light spot decomposition).
A few examples of realized projects will be presented where such complex facetted surfaces are used to reach a special quality of light. Using novel techniques like 3D-Tailoring, each facet can be designed to individually create the desired (e.g. uniform) illuminance distribution on the target surface - in this case, a large facade. For this particular application, we chose to impose a square boundary for each facet, in order to tile the rectangular aperture of the secondary mirror without compromising efficiency.
Examples of realized sophisticated lighting products
(daylighting devices and luminaires) will be presented, where complex systems are used.
These systems are built up on reflective and refractive border surfaces (reflectors, lenses etc.).
The surfaces are preferably composed on symmetrical and analytical geometries, whose optical behaviour is well known. In the case of complex surfaces they are computed point by point by special calculation methodes to fulfill special photometric requirements, which are not solvable with conventional design methodes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.