Feature Article

Clean, Fresh Air: Getting What We Need

Human health probably benefits from more fresh air than current ventilation standards require. But pulling in outdoor air can mean pulling in pollution.

The Tower at PNC Plaza overcame outdoor air quality issues and found a way to employ natural ventilation with this punctuated façade. 

Photo: Connie Zhou Photography
If you’re designing an expensive, high-end office tower, you’d better be sure the people inside of it can do their best work. So as Ben Tranel, AIA, principal at Gensler, began working on the Tower at PNC Plaza in Pittsburgh, he thought a lot about air.

“When people are working their hardest, you always hear them say ‘Let’s go out and get some fresh air,’” Tranel told BuildingGreen. “They say that because they want to get more oxygen—to feel the variability of the breeze. We wanted to see if we could create that feeling.”

The firm thus set out to design the 33-story LEED Platinum tower to be completely naturally ventilated for much of the year. But they ran into a problem. Pittsburgh is ranked the eighth-most polluted city in the U.S. for year-round particle pollution by the American Lung Association and is fourteenth for short-term particle pollution.

This conundrum is not unique. Increasingly, the desire to provide more fresh air to our interiors—driven especially by recent research that links fresh air with heightened cognitive performance—is colliding with the realization that there might not always be fresh air to be had.

All of this has given rise to a new market for air quality sensor technologies, which are paving the way for dynamic response natural ventilation systems as well as driving innovations in filtering strategies. Yet surprisingly, we still don’t really know how much fresh air is optimal for human health or productivity, or what exactly about that air is beneficial. So while vast quantities of air quality data may soon be available, some answers will likely remain shrouded in haze.

Originally published November 7, 2016 Updated October 17, 2019