CO2 sensors

I have a few Z wave smoke/carbon monoxide detectors. I was hoping to find some other CO2 sensors to take readings and check the different CO2 levels in my house.

I have the netatmo weather station but is there anything else that gives the value of the CO2 levels in your house?

@thrash99er withings smart body analyzer (scale) does this. Unfortunately there has been no response on the integration status. I wanted to cycle the fan from my nest when the Co2 levels get high in the bedroom in the middle of the night.

CO2 Level needs to be added as an official capability for this to work. I have the netatmo sensor and would also like to do this.

@jodyalbritton I have my Netatmo integrated and it reports CO2. Would it be possible to build a custom device type to query the Smoke/CO2 detectors for their CO2 level?

Or are they reporting CO2 true or false?

I have the first alert smoke combo. It detects carbon monoxide and it only reports true or false as far as I can tell. CO(carbon monoxide) is different than CO2(carbon dioxide) anyway.

@jodyalbritton yea. You are getting the netatmo to report the CO2 levels though correct?

It does. It reports it as an attribute. The problem we have now is that it is not really useful outside of the netatmo device interface because it is not a true capability. You cannot subscribe to the events nor require a CO2 sensor in any smart app you write. Because of this it would have to be a polling app that checked for your specific C02 attribute and then turned on the fan to circulate. It has been brought up in the developer discussions that we need more capabilities like CO2 level added to the official taxonomy.


Hi @jodyalbritton - I wanted to see if any progress has been made on adding capabilities for these types of sensors. Specifically:

  • Carbon Dioxide (CO2)
  • Volatile Organic Compounds (VOCs)
  • Particulate Matter (either PM 2.5 or PM 10) (ug/m3)
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You can achieve this with a sensor like this:
…combined with a Mimolite using its inputs. We’re doing this old school right now (the Co2 sensor is connected to HRV dry contacts) however I also use the mimolites to operate and monitor status of our building windows.

The sensor needs to be powered by the 24volt output on your furnace. Mimolite is powered by a wall wart…so you can install this in your furnace room. Use the Mimolite input in ST to trigger your HRV. I manage a second HRV with a simple AEON switch which monitors occupancy vs inside (ecobee) and outside (weather underground) temps.

If you read the blog post done by Co2 meter (I have no connection with them) you’ll see that the HRV often does not have to run at all, particularly on windy days.

My staff likes the Tongy unit as the LEDs on the front signal Co2 levels and also allow manual override. It’s been dead reliable too.

I’d be stunned and amazed if ecobee or similar does not integrate a Co2/moisture sensor into their system. It’s a niche that is open right now in the HVAC market. A lot of power and BTUs get wasted running HRVs. On the other side, my older home with four occupants was hitting 1700ppm CO2 regularly. Suggested levels are 600-700ppm. Outside air is about 450 ppm. Adding a self contained Panasonic ERV fixed this. I control this unit via ST and a Zwave switch for power. I use the LFM20 to toggle high/low speed based on our occupancy.

This thread is my review on the small Panasonic ERV controlled with ST: