Harvard study finds doubling the amount of outdoor air in office buildings doubles workers’ cognitive test scores
Ever have a hard time concentrating, focusing or being productive at the office? A recent Harvard study suggests it could be because you’re not getting enough fresh air.
In the 1970s, efforts to conserve energy in the U.S. included tightening up “leaky” buildings and reducing ventilation rates so buildings didn’t have to heat or cool as much fresh air.
This led to a buildup of indoor pollutants and the birth of a phenomenon known as “sick building syndrome,” marked by symptoms like fatigue, eye irritation, headaches, coughing, and chest tightness.
Study after study has shown that the amount of ventilation, or fresh outdoor air brought inside, is a critical determinant of health. Increased ventilation reduces sick building syndrome symptoms, cuts absenteeism, and even reduces infectious disease transmission.
The new study shows it also improves cognition and makes employees more productive.
Researchers enrolled 24 “knowledge workers” — managers, architects, and designers — to do their normal work routine in a highly controlled work environment at the Syracuse Center of Excellence for 6 days from 9 AM to 5 PM.
Without the workers’ knowledge, the researchers changed the air quality conditions from conventional to “optimal,” meaning they doubled the amount of outdoor air being brought in through the ventilation system.
We also changed the level of volatile organic compounds in the space by controlling the number of surface cleaners, dry erase markers, dry cleaned clothing, and building materials that emit these toxic chemicals.
Lastly, the researchers tested various levels of carbon dioxide in the air: low levels (600 parts per million) that result from high ventilation rates, a typical level seen in many offices (950 ppm), and higher levels that are commonly encountered in U.S. schools (1400 ppm).
At the end of each day, they tested the workers’ decision-making performance using a standardized cognitive function test.
The combination or removing volatile organic compounds and doubling outdoor air ventilation rates, increased cognitive test scores by 101 percent.
“Our estimates show that the cost of doubling ventilation rates would be less than $40 per person per year,” writes the study’s lead author Joseph G. Allen, director of Harvard’s Healthy Buildings program.
“When energy-efficient ventilation systems are used, the cost would be $1–$10 per person per year.”
Meanwhile, Allen estimated the value of increased productivity at $6,500 per person per year.
“We’ve all struggled to concentrate in a conference room that is stuffy and warm,” Allen writes. “When a window or door is opened and fresh air comes in, it breathes life into the room. Businesses would benefit from recognizing this.”
Ben Franklin recognized this truth nearly 300 years ago: “I am persuaded that no common air from without is so unwholesome as the air within a close room that has been often breathed and not changed.”