Reasons to consider an air quality monitor
Indoor air quality monitors like this unobtrusive wall-mounted radon monitor can provide peace of mind by measuring your home's pollutant levels. PHOTO COURTESY OF AIRTHINGS
By Christine G. Crocker
Executive Director, Maine Indoor Air Quality Council
WHAT DO HOME IAQ MONITORS DO?
Indoor air quality (IAQ) monitors are small electronic devices that continuously measure the levels of pollutants in your indoor air and deliver that information on the device or a digital app. As a result of COVID-19, most people now understand there are things present in their indoor environment that can make them sick—many of which you can’t see, smell or taste. That’s what makes IAQ monitors so useful: They can detect the presence of contaminants and inform you about pollutant levels that may require action. As we say in the IAQ field, “You can’t manage what you don’t measure.” Measurable data is the first step toward managing an indoor environment that is healthier for you and your family.
WHAT TO EXPECT FROM YOUR DEVICE
There are two key things to remember about home IAQ monitors:
No single device can monitor all the indoor pollutants that can make you and your family sick. More comprehensive monitoring of your home environment may require the purchase and use of more than one type of device.
Home IAQ monitors are not the calibrated pieces of equipment used by professionals to measure indoor pollutants. That said, the home monitors are pretty darn good, and they can spur you to take immediate and long-term action to reduce elevated pollutant levels.
The Airvalent measures a room's carbon dioxide, relevant humidity and temperature in one compact device. PHOTO COURTESY OF AIRVALENT
What I learned monitoring my home’s IAQ
A couple of years ago, I participated in a Reducing Outdoor Contaminants in Indoor Spaces (ROCIS) cohort project to learn more about my home’s indoor air quality. As the executive director of the Maine Indoor Air Quality Council, I thought I knew a lot about my home’s indoor air quality. Well, whoops— maybe not so much. Here’s what I learned:
Cooking anything on my electric stove top creates a lot of particle pollution in my kitchen, and my range hood doesn’t exhaust well from the front two burners. I now regularly use the back burners with the fan on.
My outdoor air quality in the wintertime was terrible due to wood smoke getting trapped in my bowl of a backyard. This meant my indoor air quality wasn’t great either. I now have two robust air-cleaning devices and an energy recovery ventilators (ERV) with high-quality filters.
Opening my upstairs bedroom windows in the winter did nothing to ventilate my bedroom and instead increased my entire house’s levels of particulate matter from outdoors.
My radon levels fluctuated daily both in the basement and in my living space but never enough to warrant mitigation. It was fun to see the numbers change.
More than three people in my dining room raised CO2 levels above 1,000 parts per million (ppm). A lot of hot air in there, I guess. Even with the new ERV, the dining room CO2 monitor still hits 1,000 ppm. I crack open a window and use my range hood exhaust to draw additional fresh air through the space. Boom. Mischief managed.
types of Indoor Air Pollutants
Here are the pollutants you can measure with readily available IAQ monitors and what to do if your monitor indicates elevated levels.
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Why you should measure
Knowing your temperature and humidity levels can help you identify when indoor conditions are too damp, which increases the risk of mold and bacteria growth. Some devices will even calculate dewpoint—the point at which moisture in the air becomes liquid moisture on a surface (like morning dew on grass). Preventing moisture is the key to preventing mold growth.
Risk to health
For those who are sensitive to it, mold causes a broad array of allergy-type symptoms (itchy eyes, runny nose, coughing, sneezing, mild rashes) and is a common trigger for those with asthma. More serious health effects are limited to those with underlying chronic health issues, such as autoimmune disease.
What to do in case of elevated levels
If your indoor humidity is consistently above 60%, reduce levels with dehumidification and ventilation.
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Why you should measure
CO2 is what people emit each time they exhale. Monitoring CO2 is a useful way to identify if you and your family are getting enough fresh air ventilation in your home.
Risk to health
High levels of CO2 can lead to fatigue, lack of productivity and temporary reduction in cognitive function. High CO2 (above 1,000 ppm) is often an indicator of inadequate ventilation, which causes increased exposure to pollutants trapped indoors.
What to do in case of elevated levels
When CO2 levels rise above 1,000 ppm, increase ventilation in the space.
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Why you should measure
Radon is a colorless, odorless radioactive gas that comes up out of the ground and gets trapped indoors; 1 out of every 3 Maine homes likely has a radon problem.
Risk to health
Radon causes lung cancer. It is the #1 cause of lung cancer in nonsmokers and the #2 cause of lung cancer nationwide.
What to do in case of elevated levels
If your radon in air levels are frequently at or above 4.0 pCi/L, install a radon in air mitigation system.
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Why you should measure
Small particles floating indoors can be inhaled deep down into the lungs. These particles are generated by combustion appliances, wildfires and everyday living, including dust, skin, home repair debris and viruses.
Risk to health
Small particle pollution can increase the risk of short-term lung infections and long-term lung disease as well as cardiovascular disease, inflammation and reduced life expectancy. Small children and older people are more susceptible to health effects from exposure to small particle pollution.
What to do in case of elevated levels
Prevent exposure to small particle pollution at the source. Use kitchen range hoods that vent outdoors, use HEPA vacuum cleaners, and seal off areas being renovated from the rest of the home. Increase ventilation. And use air-cleaning devices.
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Why you should measure
VOCs are emitted as gases from household cleaning products, personal care products, paints and varnishes, furnishings and much, much more. Almost anything with a significant odor is giving off VOCs.
Risk to health
Common symptoms include eye and nose irritation, coughing, headaches, nausea and dizziness. Long-term exposure can damage vital organs and cause cancer.
What to do in case of elevated levels
Reduce the use of products that release VOCs indoors. Increase ventilation. And use an air-cleaning device capable of capturing gases and VOCs.
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Why you should measure
Carbon monoxide is a byproduct of burning fossil fuels. Like many indoor pollutants, it is colorless, tasteless and odorless.
Risk to health
Exposure to low-levels of CO can cause headaches, dizziness, and exacerbation of asthma and heart or lung conditions. High levels of CO can cause death.
What to do in case of elevated levels
Regularly service all devices that burn fossil fuels. Prevent CO from coming into living spaces from attached garages. And increase ventilation. Note: CO detectors are required in most single-family homes as well as all rental properties in Maine.
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Why you should measure
NO2 is generated when burning anything indoors (e.g., gas ovens and cooktops, unvented heating appliances, fireplaces and woodstoves, cigarettes, candles).
Risk to health
Exposure to NO2 can irritate airways (coughing, wheezing, tightness in the chest) as well as exacerbate asthma and contribute to development of long-term lung disease, such as chronic obstructive pulmonary disease (COPD).
What to do in case of elevated levels
Regularly maintain all combustion appliances, use a rangehood exhausted outdoors every time you cook or bake and only use direct vented combustion appliances. Use an air-cleaning device designed to capture gas pollutants.
Some Home air quality monitors on the market
The following is a list of devices used by members of the Maine Indoor Air Quality Council and others in the general IAQ industry. These are not intended to be recommendations for specific devices but rather to provide an understanding of the types of devices available in the marketplace and how they are being used to make indoor environments healthier for occupants.
Prices listed are current as of 2024 and may be subject to change.
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What it monitors: Radon, PM 2.5, PM 1, CO2, humidity, temperature, VOCs, atmospheric pressure
Cost: $200-300 at airthings.com
Testimonial: “I find it to be very useful and insightful about the real-time air quality in our residence. It’s wireless, and I can review the readings and parameters on my phone or laptop. It’s also expandable as a hub, so additional wireless units can be set up in other rooms. When we purchased it, radon had been my initial concern, but since installing the air monitor, I now see PM 2.5 and CO2 as other issues. The seasons when we have the windows closed are most challenging. At this point, I am leaning towards swapping out the existing ERV to a larger unit to deal with the closed window seasons.”
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What it monitors: Radon, VOCs, humidity, temperature, atmospheric pressure
Price: $200-250 at airthings.com
Testimonials: “I have AirThings Wave+ installed in my residences and rental units. It provides a lot of information including radon levels and has good software .In my rental units, I guarantee good air quality and allow the occupants to monitor the measurements. The ongoing monitoring is a means of assuring them that the HRV/ERV is operating satisfactorily.”
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Measures: Radon
Price: $150-200 at airthings.com
Testimonial: “The continual radon monitoring is so helpful. It’s been interesting to move it from floor to floor to see the difference in the radon levels. One surprise for me was how much the radon levels change from season to season. We only moved in this January, so I don’t have a full year’s data yet. But while the passive system we installed seemed to work fine during the winter months, radon levels suddenly shot up this spring. So now I may be installing a fan system. If we had only done a single point lab test in the winter, we would not have known!”
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Measures: CO2, temperature, humidity, and atmospheric pressure
Price: $150-200 at aranet.com
Testimonial: “I like it because it shows the reading boldly, is battery-powered and therefore easily movable from room to room, and the data can be downloaded easily via Bluetooth. I learned to keep the bedroom door open when running the AC. Prior to that I had high CO2 (above 1,000 ppm) after days with high heat (above 75 degrees) and high RH above 60%)."
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What it monitors: Temperature, humidity, CO2, VOCs, PM2. 5
Price: $200-250 at getawair.com
Testimonial: “I have two—one in home office and one in bedroom. The company puts them on sale frequently; I think I got mine as buy one, get one. The on unit display and IAQ score is good because it’s easy to see quick live evaluation of conditions. If I see a low IAQ score on the unit (under 100) , then I check the companion app to see what factors are tripping the low score and how that data has been logged over time. Ease of use is a big plus for these. I can see these being useful for others who have less IAQ knowledge, too. In terms of what I do in response, I have adjusted the relative humidity in my home when it’s outside of 40-60% with a humidifier, ventilation or dehumidifier, and I have responded to low oxygen and CO2 buildup by opening windows. I’ve also used the temperature log to correlate that with things like sleep quality.”
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What it measures:
Price: $50-100 at co2meter.com
Testimonial: “Plenty big enough display to see across the room and can be used as a plug-in or battery. I have it set to alert me at 1000 ppm CO2, and when it goes off—which it does when I have three people and a couple of dogs in the room—I add ventilation to the space with open windows and kitchen exhaust.”
Further resources
US EPA website on low-cost air pollution monitors and indoor air quality: epa.gov/indoor-air-quality-iaq/low-cost-airpollution- monitors-and-indoor-air-quality
For more information about IAQ: maineindoorair.org
This article appeared in the Fall 2024 edition of Green & Healthy Maine HOMES. Subscribe today!
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