A team of engineers at Purdue University has been conducting an experiment to identify indoor air contaminants and ways to control them.
The study involves thousands of sensors being installed in an office space called the Living Labs, at Purdue’s Ray W. Herrick Laboratories.
It uses an array of sensors to precisely monitor four open-plan office spaces and track the flow of indoor and outdoor air through the ventilation system. The team developed a new technique to track occupancy by embedding temperature sensors in each desk chair.
Through use of the Living Labs, Boor’s team has begun to identify previously unknown behaviours of chemicals called volatile organic compounds, such as how they are transformed in ventilation systems and removed by filters.
Assistant Professor of civil engineering at Purdue University, Brandon Boor, says it is important to understand what’s in the air, and what factors influence the emissions and removal of pollutants.
“The chemistry of indoor air is dynamic,” says Boor.
“It changes throughout the day based on outdoor conditions, how the ventilation system operates and occupancy patterns in the office.”
The data shows that people and ventilation systems may impact the chemistry of indoor air more than anything else in an office space.
Eating an orange or wearing deodorant could have a bigger impact on the air environment than you think.
Boor teamed up with researchers at RJ Lee Group to develop a highly sensitive “nose” – an instrument that scientists call a proton transfer reaction time-of-flight mass spectrometer.
The instrument is typically used for measuring outdoor air quality and helps “sniff” out compounds in human breath, such as isoprene, in real time. Boor’s team found that isoprene and many other volatile compounds linger in the office even after people have left the room.
“Our preliminary results suggest that people are the dominant source of volatile organic compounds in a modern office environment,” says Boor.
“We found levels of many compounds to be 10 to 20 times higher indoors than outdoors. If an office space is not properly ventilated, these volatile compounds may adversely affect worker health and productivity.”
Ozone that enters an office from outside will disappear inside, because it interacts with other indoor particles to form new compounds.
For example, the compounds from peeling an orange will mix with ozone and form new, super-tiny particles. At one-billionth of a metre, the particles are small enough to get into a person’s lungs and be a potential hazard.
The researchers also believe that the effects of volatile compounds in an office may impact the outdoors. Chemicals from products such as deodorants and hair spray that are vented outside could impact outdoor levels.