[virtual_void]

Interesting. We have a gas stove and a gas furnace. Furnace was changed a few years back and coincides with worse asthma symptoms for both me and my youngest son.

Anyone have any air quality sensor recommendations? Preferably one that i can easily extract data from for analysis.

[koolba]

Barring a completely incorrect install, the exhaust of the furnace should be completely vent out of your home. The indoor air is warmed by passing against a heat exchanger.

If you’re having issues with air quality have your humidity levels checked. If it’s too low, a furnace attached humidifier will solve that by adding humidity to the treated air.

[RHSeeger]

We have a fairly new forced hot air heating system, and it has a humidifier in-line. It's amazing. You don't really notice it so much until you don't have it. When I'm in a house with forced hot air that doesn't have it, I find it painful. I was at a hotel in DC a while back that had the air on all evening, and my eyes hurt fiercely, dry due to the air. I don't get much of that at home (I'd get none, but... my eyes are broken enough that they're constantly dry to start with).

[danans]

> Anyone have any air quality sensor recommendations?

Search the HN archive. There are lots of debates and discussions about air quality sensors, especially around the time of the West Coast US fires.

But from right now, every time you turn on your gas stove or oven, open a window and set your stove extractor fan to maximum, even if it briefly makes your house cold.

[scottlamb]

I don't recall any NO2 sensor recommendations in particular, and that wouldn't have been a focus during the fires. In general though folks here discussed AirGradient kits. https://www.airgradient.com/open-airgradient/kits/ I bought a stack of them, and I recommend them. The Pro kit at least has extra I2C module spots on the board (one for 3V3 modules, one for 5V modules). They sell a SGP41 module for VOC, and (I didn't know this until I looked at the spec sheet [1] just now) it also supports NO2. The output's apparently an "index" rather than calibrated physical units that you could compare to the threshold/graph in the post though.

(btw: iiuc the "special" thing about the SGP41 module sold by AirGradient as opposed to some Alibaba vendor is that the AirGradient one doesn't come with surface-mounted terminating resistors installed. If you buy one from somewhere else and want to plug it into the AirGradient board, you need to desolder those because the AirGradient's I2C bus is already terminated elsewhere.)

I have an older SGP30. Less luck there; it does VOC and CO2, no NO2.

[1] https://sensirion.com/media/documents/5FE8673C/61E96F50/Sens...

[virtual_void]

Thanks. Will take your advice on both counts!

[anamexis]

Depending on your inclination for some DIY, AirGradient makes great kits. Open source and easy to use however you want.

https://www.airgradient.com/open-airgradient/kits/

[DoingIsLearning]

> Furnace was changed a few years back and coincides with worse asthma symptoms for both me and my youngest son.

As others have said, if correctly installed you should not have any furnace exhaust indoors.

You should _always_ have at least a Carbon Monoxide alarm (CO) installed in the furnace room. If there is no monoxide leak it's unlikely that other particulates are escaping. The CO alarm should be installed in your furnace room irrespective of whatever sensor analytics you would like to add for your investigate.