CSI: My Air

Earth Day 2021 is this Thursday, 4/22, and this year’s theme is “Restore Our Earth”. I kicked the theme around in my brain for a few days, and I keep coming back to the fact that it feels kind of intimidating to me. Would that I could restore the whole earth, you know? To me, Earth Day is and has always been about education about environmental issues and then taking action, and this year is no different.

In a year(+) when so many things have felt too big to take on, maybe it’s helpful to also break things down further when we think about what impacts we can make on Earth Day. Can I get rid of all the plastic in the oceans? No, but maybe I can make choices as a consumer to limit my own consumption of plastic like taking compostable bags to the grocery store to bag up fruits and veggies. Can I make all the air everywhere safe and healthy to breathe? Sadly also no, but I can monitor the quality of the air I’m in most of the time to help make informed choices about how to operate my building.


Parking garage demo before high-rise construction began

A few years ago, our office got an indoor air quality (IAQ) sensor from Senseware. A new high rise condominium and hotel building was being built across the alley from our building, and a lot of us noticed we were getting headaches and allergy symptoms, and desks had started collecting a lot of dust. The IAQ sensor helped us ID what contaminants were at high levels to get a feel for what could be bothering us. Spoiler, particulate matter (PM) was high! I also used it a lot to check if I felt hot because the space temperature was truly warm, or if I was imagining it (the space temp was usually truly warm). Over the past year, Cyclone’s IAQ monitoring efforts have ramped up with the release of our airPLAN service, and I got to bring a sensor home to my condo to check out the air quality there too.


It may not shock you that the first thing I wanted to test was, once again, temperature-related. My unit has floor-to-ceiling windows on the north and east faces, and many mornings—even in the winter—we wake up boiling because of the heat gain from the sun. The IAQ sensor confirmed that our indoor space temperature was, indeed, increasing due to the solar load. In fact, the sun provided enough heat to our space to take care of its entire heating load until 4 p.m. (i.e., the heat didn’t kick on all day).

January 28 – 30 solar heat gain

Even when the OATs were sub-zero in the beginning of February in Chicago, the sun was able to raise our indoor space temperature by over 3°F and keep it above 71°F for over six hours. When it’s cloudy, however, the solar heat gain all but disappears, as you can see in the grey-box day above.


The next metric I homed in on were volatile organic compounds (VOCs). From the Minnesota Department of Public Health:

Volatile Organic Compounds (VOCs) are a large group of chemicals that are found in many products we use to build and maintain our homes. Once these chemicals are in our homes, they are released or “off-gas” into the indoor air we breathe. They may or may not be able to be smelled, and smelling is not a good indicator of health risk.

Common examples of VOCs that may be present in our daily lives are: benzene, ethylene glycol, formaldehyde, methylene chloride, tetrachloroethylene, toluene, xylene, and 1,3-butadiene.

There are currently no federal or state standards for VOC levels in non-industrial settings, but the Senseware platform specifies an acceptable range of 65-220 ppb. Short-term (hours to days) exposure to high levels of VOCs can cause symptoms like headache, dizziness, eye and nose irritation, and worsening asthma symptoms. Long-term exposure (years to lifetime) can cause things as severe as cancer, liver and kidney damage, and central nervous system damage. As a headache and occasional migraine sufferer, if there were high levels of VOCs in our house, I wanted to know so I could try to mitigate them.

VOCs & Cooking

The IAQ sensor was initially in our kitchen, since I wanted to see how using our gas range affected VOCs in that space. At Cyclone’s Innovation Rodeo last summer (which you can watch here), one of the speakers mentioned that gas stoves can cause high levels of VOCs. I like to cook and bake with ours a lot–was I accidentally poisoning us? The IAQ sensor confirmed that no, I wasn’t. It’s obvious when we’re heating food versus not on the Senseware dashboard, but turning on then stove or oven, alone, didn’t push VOC levels into high levels. The worst cooking-related VOC levels occurred when I accidentally baked bread a little too aggressively a couple of times, which you can see below.

January 31 – aggressive bread-baking

It’s important to qualify that observation with some information about my building. I live in a high-rise residential building that has constant bathroom exhaust, and 100% outside air is delivered to the hallways of each floor via a makeup air unit. Our unit also has operable windows and a balcony door that we open at least a little bit almost every day (see the 75°F wintertime indoor temperatures, above). My point is that VOC levels may have been lower in my unit than they would in others because there’s a lot of fresh air in here. The IAQ sensor actually confirms this, too, since CO2 levels in our unit are typically only slightly higher than outside levels (550 ppm inside vs. around 400 ppm outside).

 VOCs & Essential Oils

Near the end of this February, I found myself down a VOC internet rabbit hole, reading an article from Science Direct called Ten Questions Concerning Air Fresheners and Indoor Built Environments. Among other things, it discusses how products that are designed to improve the indoor environment can end up posing health risks like migraines, asthma attacks, and breathing difficulties.

The orange

One question in the article got to the heart of something I had wondered: “What are the differences in aroma compounds (e.g., limonene) emitted from air fresheners versus truly natural sources such as oranges?”

With the help of the IAQ sensor, I decided to do an informal experiment. I would run an essential oil diffuser to see what kind of VOC levels it produced; then I would peel an orange and see what its levels looked like. My hypothesis was that the oil diffuser would create higher VOCs since it could have any number of natural or synthetic VOCs in it. Also, the diffuser gives me a headache sometimes, but I generally think orange peels smell nice.

For the first part of the experiment, I used three drops of oil from a 0.5 oz bottle of Capri Blue “Volcano” in three ounces of water in a Vitruvi diffuser. The bottle suggests 5-10 drops of oil for every three ounces of water, but I knew from experience that my headaches can’t tolerate that much. I ran the diffuser for around 10 minutes, then I ran a Blueair Blue Pure 211+ Air Purifier to return VOCs to near their starting level. Then I peeled a navel orange and left it on the counter for a while. Like I said, informal experiment.

Guess what: my hypothesis was wrong. The VOC levels throughout the test are in the graph below, where you can see that the orange peel produced VOCs around 1.4 times as high as what the diffuser produced.

I was a little confused by the results, but I have a few thoughts about what could explain them. First, and I think most importantly, I don’t know the concentration of the oils in the orange peel compared to the essential oil. It’s possible (likely, even) that the concentrations of oils in the orange were much higher than in the essential oils. In a better experiment, I would have known the orange oil concentration to be able to make an…apples to apples comparison.

Even though the experiment didn’t turn out the way I expected it to, it did made me think about how much more we know about what’s in the orange peel than the bottle of essential oils. Even the small amount of the essential oil blend gave me a headache during the experiment, which makes me think that, while it produced lower VOCs levels, I know way less about its ingredients; particularly since the ingredients aren’t listed on the bottle. As Huffington Post reported in 2019,

Essential oils are not regulated by the Food and Drug Administration, meaning their marketing is more or less a free for all. There are few rules or regulations monitoring the production and sale of essential oils, so it’s really up to the consumer to research what they do and how well they work.

Brining this back to the spirit of Earth Day, my favorite part of having the IAQ sensor in our house has been being able to use it as a tool for my own education. It inspired me to learn a lot more about VOCs than I had before; I’ve actually stopped using candles and oil diffusers all together as a result. I’d rather open a window or run an air purifier to try to reduce VOC levels, as opposed to layering more VOCs on top of the ones that are there already. Anecdotally, I actually have had fewer headaches and migraines.

Future Tests

The more I use the sensor as a tool to investigate, the more things I think of that I want to investigate. A fellow HOA board member in my building has a feeling that the suction his bathroom exhaust has lost power over the years. I think mine is generally fine. We’re planning to run an experiment where we keep the sensor in my bathroom for a week and see how quickly humidity drops down after showers and baths; then we’ll deploy it in his bathroom and compare the humidity drop times in his.

Some residents in my building complain of pervasive cannabis odor migration on their floors. One resident has agreed to let me deploy the sensor in her unit, and she’ll record when the odor is especially strong, so we’re able to get a feel for what happens to the air quality at those times. I suspect that we’ll elevated VOCs and particulate matter in her unit, but we’ll have to wait and see.

CSI Your Air

Do you ever wonder about the air quality in your space? Cyclone has a solution for you! Check out our airPLAN service.

Cyclone Energy Group airPLAN

Trusted Advisors + Technology = Enhanced Built Environments

Creating a healthy indoor environment for your occupants is fast becoming the new standard. We now offer airPLAN as a subscription based service. When you subscribe to airPLAN, you not only get sensors, nodes and access to real-time air quality reports, you also get a team to help you monitor the data, investigate any potential issues and discuss innovative solutions to improve your property. 

For more detailed information on airPLAN service, click here and contact us to get started at IAQ@cyclone.energy or 312.945.8443.