Indoor Air Quality: Why It’s Important and How to Manage It

Much conversation revolves around outdoor air quality, but many factors—environmental and health-specific—bring indoor air quality to the forefront of the conversation as well. Maximize a home’s air quality with monitoring.
Smartphone with launched application for temperature adjustment

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Increasingly, air quality—indoor and outdoor—is a prominent topic of discussion. To combat wildfires, smog and viruses, experts are talking about what measures to take to ensure that air quality is viable and healthy for us to breathe. This includes indoor air quality, a consideration that some have overlooked in past years.

Still, indoor air quality is an important component of a healthy household, which is why it should matter to you and to your clients. Unlike outdoor air quality, though, we don’t have meteorologists and weather apps monitoring it for us, telling us if it’s safe to go outside. That’s one of the reasons it’s important to have some basic knowledge of indoor air quality to help educate yourself and clients.

“During a given day, indoor air quality can fluctuate pretty significantly based on human activity,” says Oyvind Birkenes, CEO of Airthings, a company that sells indoor air quality monitors.

Factors such as the amount of people in the home and what’s being cooked can affect indoor air quality. Likewise, outdoor factors like disaster events and weather events and proximity to the natural environment or a city center can also affect indoor air quality. That’s why it’s important to have constant monitoring over time, says Roei Friedberg, CEO of Aura Air, an air purification company.

“Through real-time measurement, we can understand different trends and patterns and therefore provide users with actionable insights,” Friedberg explains.

This kind of measurement, done over time and consistently and the insights it provides, helps people make informed decisions.

“Monitoring air quality over time allows you to establish a baseline average that will illustrate whether you have a long-term problem or a short-term variation from the norm,” Birkenes says.

Air quality sensors are meant to measure a variety of factors to give you insight into the air quality of your home. These metrics give you a holistic view of the quality of air you breathe and can make educated decisions based on the information. To test this, we placed air quality sensors from Airthings, Amazon and Aqara around our home and tracked the various metrics over several months. Here’s what we found:

Air Quality Index

The air quality index is a basic measurement of overall air quality in a specific location or space. It ranges from 0 to 500; the higher the number, the worse the air quality. We found that each company’s device registered our home’s overall air quality index as good, but there were some external factors like construction on our home, the onset of seasonal allergens and other seasonal changes that made it worth digging into the more targeted measurements.


One of the first issues we noticed in our house while testing these sensors in the winter was that the air in our house was dry, at around 20% humidity. The Mayo Clinic says that a comfortable humidity level for indoors should be between 30% and 50%. Lower levels can cause issues like dry skin and irritated noses. High levels can make people feel congested. Long-term high humidity levels can cause serious issues such as mold.

We installed a humidifier and found that our home has since consistently been at 45% humidity across the seasons. We also found that all three sensors did a good job of tracking and updating humidity changes and were on par with one another.

Volatile Organic Compounds

Volatile organic compounds are a large and diverse group of compounds that volatilize into the air at room temperature. In homes, VOCs are harmful air pollutants, coming from all kinds of household staples such as air fresheners, cleaners, carpeting and new furniture.

They are among the “most common sources of unhealthy indoor air quality” factors, says Bharti Patel, CTO for air filter and purification company Alen.

“With proper ventilation, one can usually mitigate VOCs from household chemicals and cleaning supplies,” Patel advises. “Open windows to bring in outdoor air to increase airflow and ventilation when painting or after a new carpet is installed. When cooking, always use the vent hood and ensure the vent hood filter is clean.”

Particulate Matter

PM 2.5 refers to fine particles with a diameter of 2.5 or smaller, which includes bacteria, fungi and emissions from coal, gas and oil combustion. PM 10, the largest particles typically monitored by air quality monitoring systems, have a diameter of 10 microns or smaller and include pollutants like pollen and pet dander. 


Radon is the second leading cause of lung cancer, which has prompted many states to require passive radon mitigation systems installed at the time of construction on new homes. Buyers are encouraged to conduct a radon test when they purchase a home.

The EPA considers a level of over 4 pCi/L (picocuries per liter) to be elevated and require mitigation. The agency, however, also says that at this time, a safe level of radon exposure has not yet been determined, so any home with levels between 2 and 4 pCi/L should also be addressed.

At the moment, Airthings is the only consumer grade air quality monitoring system that detects radon and graphs it over time. The company recommends waiting 30 days to establish a baseline before taking any action based on the results. We built our home 3.5 years ago, so it has a passive mitigation system, and our radon levels are minimal. Still, I have had plenty of clients over the years find elevated levels which have been resolved with a mitigation system. Here in Minnesota, mitigation runs at about $1,200.

Carbon Dioxide

Carbon dioxide isn’t necessarily a bad thing. In fact, it’s a necessary part of the air we breathe. It’s when CO2 levels rise and overtake the amount of oxygen in a space that it becomes a problem. Too much CO2 can cause you to feel sleepy, tired or less focused. When it’s too high, it can be a serious health concern. Of the three systems we tested, we found that Airthings’ View Plus model displays CO2 levels in parts per million and will notify the user if levels are elevated.

Monitoring Leads to Solutions

From allergens to pollutants, there are many invisible factors that can affect the quality of the air in your home, making a monitor a practical investment.

Installing and using an air quality monitor means you have the information you need to fix air quality issues that exist in your home. Being able to address air quality issues means your home is more comfortable and safer. Based on the data collected by your monitor, you’ll be able to determine what kind of solution is required.