I like to look at the map to see what other people are getting for their Experimental VOC readings, for newer PurpleAir Touch models. There’s so many factors and I don’t know where others have theirs located. Mine has literally never gone below 50 ppm for VOC, and typically hovers around 80-120 even with windows open, and often goes considerably higher. We don’t use any intense cleaning products or air fresheners, etc. We are just puzzled as to what is giving these fairly high readings - often well over 200. It seems to happen in waves - getting a lot of high readings for a few weeks, for example. I would love to hear what others experience with this measure.
The default configuration the Bosch BME68x gas sensors are set up to sense biological VOCs as a proxy for CO2. The readings of your sensor are more likely to tell you about the ventilation rate of your home than air pollution from cleaning chemicals (unless they are generating hydrogen sulfide or ethanol, both of which you would be instantly aware of). See the datasheet for more details.
I suspect you will find that the reading spike when there are lots of people in your house and/or there is little to no wind.
Edit: Datasheet link for BME680, BME688 is the successor chip.
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That hasn’t necessarily been the case - we sometimes see spikes when no one has been home, or spikes even when windows are wide open. It’s a townhome so perhaps neighboring units play a role, but it has made it hard to make use of this important measure. And I see on the map that almost no one ever has a reading below 50.
When you say biological VOC’s - you mean breath, etc? I do see that it rises when we cook (gas stove), when cars enter or exit the garage below us, etc.
I do see that it rises when we cook (gas stove)
Cooking throws all sorts of garbage in the air. Turn on the vent hood!
when cars enter or exit the garage below us
I would be a lot more concerned about this. Garage air should NOT be getting into your unit.