ANy good recommendation? I have one of Netatmo, but is expensive and I do not like the company, so do not want to buy another one from them. Any alternatives?
Thanks
I build it myself using a esp32 and a MH-Z19B and ESPHOME. Put it into a smoke detector enclosure.
The LED indicates the level of CO2 (bright red is HIGH!)
If you can find a different enclosure you could put it on a shelf and power it using a USB power brick.
I have a AC/DC convertor in there because I power it using 24v AC (which was available already).
Works perfect!
3 Likes
This one is also quit good: https://www.amazon.it/dp/B00H7HFINS/ref=cm_sw_em_r_mt_dp_U_srxREbD5ZQVAY but costs 2.5x the DIY solution.
can you integrate this in HASSIO?
I presume you mean the last one?
Yès, if you add a ESP8266 or ESP32 to it like here: https://esphome.io/components/sensor/zyaura.html
Is good, athough a total price of 70 Euro is way too much for me. Will look for cheap alternatives thanks
Then I would advise the MH-Z19B with a esp8266 or esp32. Accurate and relatively cheap.
A good sensor costs some money. Be prepared to spend at least 17 euro for the sensor.
2 Likes
I did some research into CO2 measuring. the so-called “experts” say co2 is a heavy molecule so should be installed low. eg. not on the ceiling but at the same level that people inhale and away from windows and doors that may be left open. Height & location of a thermostat is good because they are usually installed there for the same reasons.
Another example they gave: When businesses store compressed co2 tanks, they put co2 sensors close to the ground to detect leaks. CO2 flows down to the ground like invisible water because it’s heavy.
just fyi because I’m installing a nodemcu + scd30 sensor with ESPhome today.
1 Like
This is a common misconception if about carbon monoxide that can be disproved by any high school-level physics student. CO is roughly the same weight as room air and readily mixes throughout a room due to the Second Law of Thermodynamics. This has actually been studied and confirmed by credible scientists. This is just one published example.
This thread is about CO2 and I don’t see any posts in this thread about CO.
Yes, they are very different.
I realized that after I posted and deleted it. Netamo makes both types of sensors.
This is false. CO2 is roughly the same weight as air and readily mixes throughout a room. This has actually been studied.
It’s pretty easy, google: co2 weight in air
Hi Klagio,
i have the same question you had previously.
I’m curious what did you buy in the end?
I’m looking for a CO2 sensor:
- below 100 euro.
- to be connected via Zwave or Wifi to home assistant
- I don’t want the eCO2 (CO2 calculated from other measurement), but real CO2 measurement.
Netatmo looks to fulfill this list, but you need to read your own data from their website while the device is in my house. Doing it this way seems stupid, because next to max polling frequencies (introducing delay on the measurement), it also relies on availability of their servers. So local polling of the device has major preference.
1 Like
i’ll add my experience too - it seemed to be almost impossible to get mhz-19b without actually receiving the fake (black pcb, no heatlamp bump on enclosure) one, i decided to go with Sensirion SCD30. I really like it - it also comes with the builtin temp+humidity and it is a little slimmer than mhz-19b.
there already is a tasmota support built in (just enable the i2c and scd30 imports and compile). everything set up in minutes. I also trust this sensor more.
the temperature readings are ~1.5°C higher than the ones taken by sht21 on the same bus, however this migh be caused by the assembly (3rd out of 3 devices on i2c bus on a breadboard) or the tasmota-hardcoded poll frequency.
I’m looking for a right enclosure that I could mount on a wall next to my shelly/sonoff-piwered light switch with possibly soldered wires to some additional pins that i could use for powering and reading the scd’s data
I believe tho, that the future is in the Sensirion’s new model - scd41, where they managed to cut the size down to 1cmx1cm - this is still true CO2 sensor, but they switched to photoacoustic technic instead of NDIR.
the units are mostly not available at sellers yet, but the sellers seeem to have them ordered already
2 Likes
l.s. as I’m testing on HA and have already used this on Tasmota , I suspect that that the temperature sensor isn’t available att all. But is this temp. the working temp off the C02 part/device/electronics itself… nothing more… the temp recorded keeps the same al the time … and comparing to 1xAM2301 sensor and 10x DHT sensr (all arond 20c ) complete off by 5 degrees…
1 Like