Posted on 2/5/2014 1:18 PM by Brent Protzman
Designing for daylight autonomy means designing a space so that it maximizes the amount of useful daylight, thereby minimizing the need for supplemental electric light. This may seem like a simple challenge, easily solved with glass walls and lots of windows, but of course nothing is that easy.
Here are five things you need to know about how to effectively use daylight while maintaining a comfortable, productive environment:
- Daylight is unpredictable. A good daylight design, which typically includes automated shades with window-based sensors, accounts for changes that happen throughout the day, and even the year, to deliver a consistent and comfortable light level in the space.
- Managing glare presents one of the greatest challenges to daylight design. Vast amounts of daylight may save energy, but uncontrolled glare can cause headaches, eyestrain, decreased productivity, and increased absenteeism, quickly offsetting achieved energy savings. Smart shading devices know when to close for glare mitigation, as well as open when glare is no longer present to maximize views and daylight autonomy.
- Only dynamic fenestration strategies will improve Daylight Autonomy metrics that evaluate both quantity and quality of daylight. Adding tinting on a window and installing overhangs reduce glare, but also reduce daylight. Increasing window size will improve daylight, but increase the potential for glare. Dynamic fenestration, such as automated shading solutions, address all these concerns.
- New building codes are driving daylight compliance. Standards and guidelines developed by ASHRAE are now mandated by the DOE. As of October 18, 2013, all state commercial building codes must meet or exceed ASHRAE 90.1-2010 standards that generally include mandatory requirements for daylight harvesting technology, known as “daylight zone control.”
- Daylight autonomy design solutions are highly scalable, and continue to come down in cost. Automated shading solutions with window sensor technology can be applied for less than a few hundred dollars per window. These sensors are effective in small or large areas of a building such as classrooms, private offices, and open-office areas.
Louis Kahn – American architect, design critic, and Yale professor of architecture – believed that light was an architectural element on par with every other element of a structure. Designing for daylight autonomy reintroduces daylight into the mainstream of modern design, and echoes Kahn’s definitive statement, “A room is not a room without natural light,” from his 1961 lecture.
Brent Protzman is a manager of Energy Information and Analytics at Lutron Electronics.