Improving Indoor Air Quality

Photo by Chris LeBoutillier on Unsplash

Indoor air pollution can get insidious. It decreases your health, lifespan and more. Since I live near a highway, I had to stay on top of this more than most others.

There are 4 major things you want to think about:

1. Particle count (PM2.5, PM10): Comes from fires, cars, brake dust, dust dust, etc. This is why living near a highway is bad, it's concentrated brake dust and such. And why living near a coastline vs. a valley is usually so good, pure air from the ocean is constantly being recycled in your environment. You manage this with particle air filters, and they are usually white.

2. TVOC: Comes from chemicals off gassing from renovations, glues and more. This is partly where "new car smell" comes from. You filter this with carbon air filters, and they are black from the carbon put into them.

3. CO2: This is an indicator of how much fresh air circulation you get, and too high of a CO2 level leads to decreased brain performance. You only fix this by circulating in fresh air, and is mostly only an issue in sealed houses.

4. Humidity: Having too high humidity can lead to mold issues very fast. The relative humidity you get from most air sensors is ok, but is actually deceptive. Dew point and absolute humidity is what matters more if you want to look it up. This is very dependent on your outside humidity. You manage this with dehumidifiers, AC units and most ideal of all, an ERV

Strategies for your living situation

You should get an air monitor that monitors particle count at least, since the causes of increased particle count are very varied. TVOC is usually one thing in your house and is obvious once you detect it.

In improving air pollution, you first want to get rid of the sources of pollution if possible, then use external devices to deal with it if you cannot. So if you have a leaking pipe causing humidity issues, fix that pipe before running the dehumidifier.

The Ideal Option, Open Windows: If your outdoor air is good, which you can see with AQI in your weather app, and the temperature / humidity is good, it's very hard to beat the raw volume and free nature of opening your windows. Many of us don't have that, as our outdoor air has either pollution, temperature or humidity issues.

Renter / Apartment: If opening a window doesn't work, you can get air filters. Most come with carbon (TVOC) and particle (PM) filter mediums. You get a trade off although between air filtering and CO2 / humidity, and since you can't rennovate your place as a renter and install ERV units and so on, this becomes a trade off. I deal with this by putting air monitors close to my windows and opening them when the CO2 or humidity gets too high, and closing them and turning on the air filter when the CO2 is low enough and the particle count starts going up. I sleep with a closed window and the air filter on, and I have an air filter for each room exposed to a window along with fans to circulate air quickly through the house.

House Owner: As a house owner, you have the most power to make your place clean with ERVs. ERVs circulate fresh air while keeping your humidity and temperature in check and filtering for particles as it comes in without much energy cost. ERVs are very chunky units although, so you need some sort of central air circulation system for most of them to make sense which is why they only really make sense for houses or a rare few condos.

Sources of pollution

You might be confused about why your house is polluted despite closing the windows and turning on the air filter. Common causes are:

1. Unsealed house: More common in older places, your house is not sealed so outside polluted air leaks in constantly. You can address this by fixing leaks and/or getting stronger air filters.

2. Over-sealed house with poor circulation: Another issue is the outside air is good, but the inside is off gassing VOCs or your have something creating a lot of particle dust or your just building up a lot of CO2. You fix this by opening your windows and circulating air with fans or use an ERV to exchange outside air while keeping your temperature and humidity balanced.

3. Bad outdoor air: You live in a valley which experiences inversions so the environment accumulates pollution, live near factories or highways or similar. You can move or filter the air and seal your house.

4. Interior Sources: You can have a leaking pipe or appliance which causes humidity issues throughout your house. You could've renovated recently and the glue and such and it is off gassing. Your kitchen air vent doesn't actually vent to the outside and particle count & TVOC goes up a lot. You either deal with this by fixing the interior cause or ventilating a lot when you do those activities.

Hope this helps!