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:

1. 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.

2. 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.

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.

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.

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

• ROCIS: rocis.org/low-cost-monitoring-project

• 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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