The new automatic blinds are one of the features rendering the renovated Secretariat Building fit for the 21st century. Not only are they instrumental in making the UN Headquarters complex significantly more energy efficient by giving the tower a “responsive façade” that adapts to the various natural light conditions throughout the day and all through the seasons of the year. They also help create a pleasant work environment with the right amount of natural light.
The blinds are pre-programmed according to the time of day and year to find the right balance of natural light for the office floors. Enough of it should stream in to allow for an agreeable ambiance that requires only minimal lighting, but too much of it should be blocked out in order to prevent the floors from heating up. In addition to the pre-programming, sensors respond to the actual light conditions outside and tilt the blinds, for example, on overcast days to let more light in. Thanks to their own sensors it takes the ceiling lights only 15 seconds to automatically adapt to changes in the amount of natural light.
It is estimated that thanks to the automatic blinds 440,000 kWh of electricity can be saved. That amount of electricity could power 93 New York households for one year. Energy savings of this magnitude result in avoiding 334 tons of carbon-dioxide equivalent greenhouse gases, about the annual greenhouse gas emissions from 60 US passenger vehicles. Sequestering this much carbon would require planting nearly 8,000 trees, and letting them grow for a decade.
Planting a tree and letting it grow is, of course, always a good idea. But letting the automatic blinds do their job is also a pretty green thing to do.