Better use of office daylighting can improve people's well-being

(Image: Pixabay CC0) - A PhD candidate at EPFL studied the use of automated control systems for blinds and electric lighting to regulate the amount of daylight in an office, and found that such systems can cut a building's energy demand and stimulate occupants' circadian rhythms, improving their health and well-being. "We spend 90% of our time indoors, in buildings where we use way too much energy," says Marta Benedetti, a recent EPFL PhD graduate in energy systems engineering. This is a problem in office buildings in particular. "When we're working, we're unlikely to get up and adjust the blinds or dim the lights in response to changes in daylight over the course of the day." Some office buildings are equipped with computer-controlled blinds and electric lighting systems that are designed to automatically provide the optimal amount of light at each time of day. These systems adapt to natural variations in sunlight by dimming artificial light sources when they aren't needed, for example, in order to take full advantage of the daylight available. But until now, engineers weren't clear on how much energy these systems really saved and what tangible benefits they brought to occupants' health and well-being. These are the questions Benedetti set out to answer in her PhD thesis, carried out at EPFL's Solar Energy and Building Physics Laboratory (LESO-PB) within the School of Architecture, Civil and Environmental Engineering (ENAC).