BASF brings daylight deep into buildings

The daylight redirection film allows natural daylight to reach to the very heart of buildings. This is done by laminating the film comprising encapsulated micromirrors into the window.

Daylight plays a key part in our lives. It regulates our body clock and biorhythm, and is vital to our wellbeing. Natural light makes us feel better, improves our concentration, motivates us at work and makes us less prone to illness. As we spend more than 90% of our time indoors, it is crucial that we get a sufficient quantity and quality of daylight.

Daylight redirection film offers many benefits

BASF’s transparent daylight redirection film (DRF) is set to revolutionize daylighting in buildings. In the future, windows will help to control levels of both light and heat. This is achieved by laminating a light control film comprising thousands of encapsulated micromirrors into windows. The light is reflected onto the ceiling and so redirected into the heart of the room. This significantly increases the amount of space in the building receiving daylight and energy can be saved.

Daylight redirection technology principle

BASF’s daylight redirection film is an innovative product for the glass industry. It is the first highly transparent light redirection system that can be laminated directly into the glazing, and delivers benefits and new functions – for all types of building, in almost any location:

Loading ...

Greater daylight autonomy

By redirecting light to the ceiling and into the heart of the room, the available light is distributed and used more effectively. The number of hours in the day when the level of daylight is sufficient, i.e. when no artificial light is required, is improved significantly. A study at over 2,400 locations worldwide shows that this increases daylight autonomy in buildings by 66 percent on average.

Substantial energy savings

The daylight redirection film can massively reduce the use of artificial light and the consumption of primary energy in offices and residential buildings. On average, the technology reduces energy consumption for the use of artificial lighting by 38%.

Larger spaces in buildings can be lit by daylight

Deeper penetration of daylight into the building allows greater coverage in buildings without compromising on light quality. Daylight conditions (e.g. European standard DIN EN 17037 on daylight in buildings) can also be met in larger rooms.

High transparency under common viewing angles

The use of thousands of micrometric mirrors in a transparent medium ensures a very similar level of transparency to standard glazing.

Less glare from daylight

Redirection of daylight prevents direct light and reduces glare from the sun, especially in summer. The use of conventional blinds such as venetian or roller blinds can be reduced.

Higher visual comfort

Redirection reduces brightness close to windows and increases it in the heart of rooms, resulting in more even illumination. Bright ceilings help to further improve visual comfort by decreasing contrast.

Easy to install in window glass

The technology can be installed in any type of glazing during glass manufacture and enhances its functions with a unique daylight management system.

Daylight autonomy in buildings can be improved by an average of 66 percent through daylight redirection technology; the technology is generally applicable. This can massively reduce the use of artificial light in offices and residential buildings, cutting the consumption of primary energy for artificial lighting by 38% on average.

The daylight redirection film is laminated into the window. The look and transparency of the window are retained as much as possible while also creating a more pleasant space bathed in daylight. Ultimately, the windows help to significantly boost the feel-good factor for residents and employees.

The DRF prototype in the NEST SolAce unit

The prototype of an insulated glass unit with daylight redirection technology was built in cooperation with a glass manufacturer and is being presented in the SolAce unit in Empa’s NEST building in Dübendorf. The triple-insulated glass unit, measuring 67x100 cm, has an outstanding Ug value of 0.7 W/m²K. The product is still in the development stage; the first-generation prototype on display is a manually constructed (laminated) proof of concept.