Google recently shared its air quality information with scientists from its Project Air View initiative in hopes to track pollution around the world.
Having conducted this project since 2012, Google has a treasure trove of data which will shed light on the extent and degree of air pollution in certain locales. While this is a good step in understanding outdoor air pollution, there hasn’t been as much effort in understanding indoor air pollution. This is alarming since we spend most of our time indoors.
“We spend around 70 years, or around 90% of our lives, inside a building,“ says Dr. Elliott Gall of Portland State University. Dr. Gall uses his lab, the Green Building Research Laboratory (GRBL), to solve the fundamental and applied research questions as it relates to indoor and urban air quality, sustainable buildings and human exposure to air pollution.
If you’re working in one of the many office buildings scattered across the US, the chances that you are breathing something other than the normal ~80% nitrogen, and 20% oxygen are pretty high. These pollutants can take the form of carbon dioxide (CO2), volatile organic compounds (VOCs), and particulate matter (PM) to name a few.
If you find this a little breathtaking, you’re not alone. Most building occupants have no idea what they’re inhaling on a daily basis. This is because indoor air quality (IAQ) research is a relatively new discipline but it’s gaining ground in building science.
“Understanding the air quality inside buildings is crucial for understanding what drives our exposure to air pollution,” says Gall. “It is a complex challenge, because inside buildings we are exposed to air pollution that may be generated indoors but also pollution transported indoors from outside. Buildings also consume a tremendous amount of energy. As we learn more about indoor air quality, we have to think about how to control indoor air pollution with low or zero-energy strategies to ensure buildings are healthy and able to meet more stringent energy consumption targets in the future.”
So, where are we at in our understanding of indoor air?
Even Vikings had air quality problems
We’ve been attempting to understand air quality since we first lit fires in caves. However, preindustrial man had little knowledge of the consequences of polluting their indoor air. A recent paper published in Experimental Archaeology explored the relationship between the inhabitants of a Viking Age house and their indoor environment by reconstructing an exact replica of a house from the Viking Age dated 870 AD and having participants live like vikings for 13 weeks switching out periodically. The results of the study showed that these intrepid, albeit brutal, explorers suffered considerably back home where they burned solid fuel in the center of their homes during the long winter months with exposure to CO2 more than twice normal levels and particulate matter 100 times greater than the guidelines set forth by the World Health Organization.
Fast forward to the 20th century and we saw the development of Sick Building Syndrome (SBS) in the 1970s where commercial building air made their occupants ill. Occupants exposed to higher levels of indoor air pollutants have decreased ability to concentrate, and experienced headaches and nausea. Causes for SBS include buildings being constructed tighter to save energy during the energy crisis of the time, decreased air changes in buildings to save money, and increased use of chemicals in cleaning agents and paints that aerosolized after or during use.
In response to this incipient threat, the American Society of Refrigerating and Air-Conditioning Engineers (ASHRAE) developed a ventilation standard, in 1973 which provided guidance on minimum ventilation requirements to help designers and engineers create environments with air quality in mind. Today, ASHRAE 62.1 (commercial buildings) and 62.2 (residential buildings) are the standards with which we ensure minimum ventilation requirements are met in our built environment.
Optimizing indoor air
So why don’t we just bring in as much outside air as possible? It stands to reason that this will dilute all the pollutants mentioned above and improve the indoor environment, right? Not exactly. As we learned here in the Pacific Northwest during the wildfire season, outside air does not necessarily mean fresh air. Plus, the more air you bring in outside of the normal inside temperature ranges, the more energy the equipment will expend trying to temper the air back to comfortable temperatures. It also doesn’t help that the industry is vacillating about the appropriate metrics for indoor air quality and their minimum values.
These challenges are not insurmountable but require an increasing amount of effort to strike a balance between acceptable indoor air quality and energy efficiency. Luckily, we are hard at work on a solution.
Like all good problems, the first step is gathering data – and lots of it. Michael Frank, VP of Engineering for McKinstry (where I also work) headquartered in Seattle, Washington recently published an article on LinkedIn where he showed indoor air quality dashboards his team has generated for our customers’ spaces. These dashboards show sensors in the spaces measuring CO2, VOCs, PM, temperature and relative humidity. They also show a comparison between indoor and outdoor air which, as we’ve seen, is becoming a critical component to assessing overall air quality. When the industry agrees on the appropriate levels for these metrics, his team will be ready to take action.
As we continue to gather data and experimental results, the industry will be listening to ensure the appropriate action is taken to improve our indoor air. These research activities and results will inform not only the metrics of what acceptable air quality is but also yield engineering solutions which are sure to spread throughout the industry and come to a building near you. It’s a privilege to be working to bring these solutions to fruition so we all can breathe a little easier.