Three Lessons on Energy-Efficient Lighting Design from Facebook

EDF Climate Corps

Three Lessons on Energy-Efficient Lighting Design from Facebook

Facebook like image CC-licensed by Ksayer1/Flickr

As I enter the first completed building of Facebook's brand-new office campus in Menlo Park, Calif., I'm greeted by a scene that feels fresh but distinctly familiar. 

An exposed steel beam punctuates a hallway. Ventilation ducts and ethernet cables run across the ceiling in full view, like veins and neural pathways. Purple knit beanbag chairs sit with other funky furnishings on concrete floors. Open-plan office spaces enable conversation and collaboration with an easy swivel of chairs. Yes, these are unmistakable hallmarks of Facebook, a company whose office design is an extension (and enabler) of its culture: social, young, scrappy, innovative and unfinished.

I'm part of a team of three EDF Climate Corps fellows at Facebook this summer looking at ways to make the company's new 1 million-square-foot office campus more energy efficient. One of my responsibilities is lighting. The Energy Information Administration estimates that lighting consumes approximately 21 percent of the energy used in U.S. commercial buildings, making lighting a vital component of any company's energy efficiency strategy.

Facebook's goals for its lighting system are simple: make efficient use of daylight, lighting controls, and efficient fixtures to save energy and keep employees comfortable, while preserving the company's unfinished, garage-like office aesthetic. I've learned a number of important lessons about energy-efficient lighting design while at Facebook. Here are my top three:

1. You Don't Have to Compromise Between Design and Efficiency ... As Long as You Plan Ahead

The best way to incorporate energy efficiency in lighting and other systems without sacrificing design goals is through integrated design. In integrated design, people involved in different aspects of building design -- from architects to engineers to energy efficiency experts -- sit down at the same table in a collaborative, iterative process. This ensures that all factors are considered from the start.

Indeed, the earlier energy efficiency is taken into account, the greater potential there is to achieve significant, cost-effective results. If energy efficiency considerations are an afterthought, the results are likely to be poorly integrated into overall design objectives and more expensive to implement.

Where can integrated design help Facebook? Despite the dizzyingly fast pace of development at Facebook's Menlo Park campus, the company can take an approach that incorporates energy efficiency expertise into the overall design process.  This can ensure, for example, that walls and ceilings are painted appropriate colors to reflect light where it is optimal to do so. As Climate Corps fellows, we are encouraging Facebook to take the integrated design approach.

2. Be Sure to Have Lighting 'Control Narratives' and Test Against Them

If you want to effectively use lighting controls such as occupancy and daylight sensors to modulate light levels and optimize energy efficiency, it is important to articulate what lighting designers call a "control narrative": a concise statement that describes how you want your lighting system to behave. Good control narratives ensure that building occupants and operators know how systems are supposed to function and that controls contractors can calibrate and test them.

How can control narratives promote energy efficiency? Take this case in point: Facebook's offices are peppered with "cozies" -- tiny 6-by-8 rooms intended for small meetings and individual phone calls. These cozies are controlled by occupancy sensors that should operate under the following control narrative:

When an occupant enters the cozy, the lights should automatically turn on to the 50 percent brightness level. The occupant can manually adjust the lights to full brightness if desired. When the room is vacated, the lights should turn off within five minutes (the minimum setting allowed by the sensor).

At least, this is how the control system is supposed to operate. On our first walk-through of the new building, it was easy to notice that many of the cozies did not operate this way. When we pulled off the face of the occupancy sensor and checked its settings, we realized that many sensors were set to turn off after 10 minutes, not five. We also realized that the sensors had other, energy-saving functions that were not being utilized at all, such as a "walk-through" setting to prevent false triggering when people enter momentarily but don't stay. (Perhaps re-adjusting these sensors could be a project for a future Facebook Hackathon?)

Developing and testing control narratives is an important practice to maximize daylight use as well, by controlling when and where lights dim or turn off in response to natural light. As EDF Climate Corps fellows, we're verifying the existing control narratives in Facebook's new offices, and promoting more energy-efficient control narratives where feasible.

3. Productivity and Occupant Comfort are Important Arguments for Efficient Design

Efficient lighting systems not only minimize energy use, but can also improve occupant comfort. As another EDF Climate Corps fellow at Facebook pointed out in her recent blog post, research shows a positive relationship between workplace comfort and productivity. Numerous studies indicate that effective use of daylight, in particular, improves productivity. Conversely, incorrect lighting design choices can lead to work environments that are overlit or underlit, have excessive glare, or are otherwise uncomfortable for workers. 

If a lighting design improvement could reduce eyestrain and help every employee be productive for even 15 more minutes per day, the combined effect at a company like Facebook is huge. At the Menlo Park campus, we're searching for ways that daylight can be used more effectively to minimize the need for artificial lighting and improve the overall office environment. 

Save energy, save money, and increase productivity -- it's a win-win-win!

Facebook like image CC-licensed by Ksayer1/Flickr