[electriclove]

Thanks for posting this! From the millions of air purifiers and filters that are sold, it is clear that people care about air quality in their homes. But there doesn't seem to be a good option for accurately measuring air quality.

I appreciate the option you linked and wish there was an English version of it. If you were to build a consumer product, which air quality sensors would you want in it?

[throwaway9d0291]

For CO2, which I've researched the most out of the various things that interest me, I'd want a Senseair K30 or S8 Commercial, an Amphenol Telaire T6613 or T6713, or a CozIR-A or CozIR-LP sensor.

For low cost, I'd go with the Senseair S8 Residential. It's not fantastically accurate but it's still a "real" sensor and you can get it for $20 from China.

For other aspects of air quality, I haven't finished researching the options yet.

[joshefin]

Thanks for sharing. I wanted to get Winsen MH-Z19B, but Senseair S8 (residential) looks like a better, more reliable option, for a DIY project. One comparison: https://www.letscontrolit.com/forum/viewtopic.php?t=3736&sta...

[throwaway9d0291]

If you'd asked me a few days ago I'd have said that the MH-Z19B is okay on a budget but now that I know you can get an S8-0053 for $20, I don't think I can recommend it.

If it's difficult for you to get the cheap S8s for some reason though, per that thread it looks like an MH-Z19B with calibration off is a decent choice.