“Multiply your age by 0.9. That’s how long you’ve spent indoors. If you live to be 80, you’ll have spent 72 years indoors,” said Joseph G. Allen (Harvard T.H. Chan School of Public Health) at The Air We Breathe: Brain Function & IEQ to underscore the importance of healthy indoor environments. While outdoor air quality metrics like particulate and ozone levels, and outcomes like asthma, are well known, much less is understood about the impact of indoor air quality. We quantify utility costs because they’re easy to meter. Measuring indoor air quality parameters is harder, and it’s been nearly impossible to objectively quantify how indoor air quality affects our brains—until now. Research conducted by Harvard, SUNY Upstate Medical University, and the Syracuse Center Of Excellence (SyracuseCOE) shows that, as moderator and Urban Green Board Chair John Mandyck puts it: “Intelligence is in the air.”
“One percent of the lifetime cost of a building is energy. We’ve made tremendous strides chasing that 1%. But 90% of the cost is the people in the building. Imagine how far we can take green building if we can prove it affects that 90%.” – John Mandyck”
It’s not only high concentrations of volatile organic compounds (VOCs) that affect us; higher levels of CO2 alone decrease our ability to think clearly and make decisions, according to the study. This goes against traditional HVAC thinking, which considers CO2 an indicator that more fresh air is needed, but not harmful on its own. The study introduced pure CO2 into a carefully controlled office space and found a clear statistical relationship between higher levels of CO2 and lower cognitive function.
To demonstrate this, the researchers put 24 knowledge workers (designers, architects, and others who work at a computer) in a task-built office environment at the SyracuseCOE. At the end of each day, they were tested on a range of cognitive functions such as information usage, strategic thinking, and crisis response through a SimCity-like program in which players act as the mayor of a city.
A range of advanced technology—from special sensors and ducting, as well as brute-force techniques like stuffing dry-cleaned shirts and pads of sticky notes in the ducts—allowed researchers to simulate office contaminants and isolate the effects of enhanced ventilation, CO2 independent of ventilation, and VOCs.
The results were stunning. According to Allen, “When we graphed the scores in conventional versus green scenarios, we see a doubling of cognitive function.” Some ways of thinking, such as information usage and strategy, saw even bigger gains. Participants were retested in the same environment nine days later and, controlling for other variables, showed near-perfect concordance in test scores.
This work has wide-ranging implications, since the vast majority of US office workers spend lots and lots of time in this kind of environment. Based on publicly-available salary information, Allen’s team estimated that the dollar value of an eight percentile increase in cognitive function due to increased ventilation and decreased CO2 and VOCs is $6,500 per year for every regular employee—and over $10,000 per year for higher-paid executives. Reduced absenteeism and infectious disease transmission boost these benefits even further. And just as important, workers would be healthier and happier in the spaces where they spend eight or more hours a day.
Doubling the ventilation can come at a cost in energy, which the study estimates at about $40 per person per year, averaged over all climate zones. Here’s a challenge for HVAC professionals: can you estimate the costs from doubling ventilation rates in NYC? I’d love to hear your thoughts in the comments section below. Another problem may be split incentives if landlords pick up the energy expense but tenants accrue the benefit.
Allen and his team are continuing to explore follow-on studies. For instance, what might be the long-term health benefits from increased ventilation? How long does it take to get back to full functioning after experiencing the ill effects of increased CO2 and VOCs? And keep in mind, this isn’t just about office workers: planes on the tarmac have some of the worst air quality routinely measured. Are pilots’ cognitive functions still impaired by the time the plane is done taxiing and is ready to take off?