Ask HN: What indoor CO2 monitor do you recommend?

Some good input on this thread such as that from brendangregg - https://news.ycombinator.com/item?id=34648021

Genuinely curious, what are the advantages of a CO2 monitor?

I mean, I get you can “track air quality” but what exactly does that mean on day to day basis?

I have a handful of these in my home and really appreciate the small form factor, long battery life, and options for accessing the data (on-screen live values via eInk display, encoded recent history displayed via QR code, or simple http server endpoint over wifi): https://github.com/davidkreidler/OpenCO2_Sensor. It was straightforward to integrate the accessories into my homebridge instance for ongoing monitoring and notifications as well.

You can make one yourself from the information in the repository or buy one from the author at their Tindie storefront: https://www.tindie.com/products/davidkreidler/open-co2-senso....

It means you know when to open the windows more to maintain fresh air.

I think much better and am in a better mood when CO2 levels are lower, or when air is fresher generally (the two generally correlate).

But I don't want to keep my windows wide open all the time because that wastes AC or heat.

So if the monitor is reading above 650, I open windows a little bit. If it's reading over 800, I open them wider. If it's under 550, I'll go back to closing them.

It's just a few times a day, but it really helps. And it's not something I can "tell" otherwise easily, because if I have brain fog or am in a bad mood then high CO2 is just one of many possible reasons -- is my blood sugar low? Did I get enough sleep? Etc.

A CO2 monitor feels just as essential to my health as weighing myself every day, no bright or blue lights two hours before bed, not overeating carbs, and so forth. It really helps with my overall alertness and productivity in a major way.

I have a https://www.birdie.design/en-us (I think it was previously called a Canary) mounted in my living room, and it's a great lil device! Overly dramatic, fun, and easy to know whether air quality is good or bad - would recommend!