We celebrated New Year's Eve at my dad's, including a fire in the (open, wood burning) fireplace. I was curious how much the wood smoke went up the chimney vs collecting in the room, and decided to take some measurements. I used the M2000 that I got when investigating whether a ceiling fan could be repurposed as an air purifier.

Here's what I found:

I started the meter running at 4:30pm, and we started the fire at about 5:30pm. I didn't write down the specific time because I thought it would be evident from the chart [1] but actually I can't see it at all.

Then at 6:45pm we lit Hanukkah candles, and the smoke from the matches being blown out had a very sharp effect. Particulate levels stayed high for the rest of the time, with both the fireplace and candles, which I attribute to the candles.

[1] Several years ago I remember reading Sam Harris' blog post The Fireplace Delusion, which argues that while we consider wood fires to be wholesome they're actually worse than smoking. And argues that this feeling of "wait, but wood fires are good!" is useful for understanding what religious folks are thinking when presented with atheism. Several years later his post had gotten jumbled in my head into saying that fireplace fires cause bad air quality in your own home, and so when I ran this experiment I was expecting to see quite high levels. On rereading, however, he spends a lot of time talking about externalities: the wood smoke that goes up my chimney goes, in part, into many other people's houses, causing a small bit of harm in each. So no conflict there.