We have tested it extensively and it is very accurate for the fraction of the costs of commercial sensors. You can build it for less than USD 20 and send the data to our cloud server or any other backend.
We also measure CO2 because if you have purifiers running you often do not have enough fresh air ventilation and your CO2 often gets very high (often >1500ppm) causing headaches and reduce cognitive performance.
We measured this in classrooms some time ago and the results were not very good.
I've seen references to this sensor before and find it a bit concerning that there's no information about how to properly use the CO2 sensor.
This sensor uses a SenseAir S8, which like most CO2 sensors, has an automatic baseline calibration algorithm enabled [0], which expects to see pure, undiluted fresh air at least once every 8 days. The only way to disable it is explicitly, through the MODBUS interface [1].
Leaving it enabled makes perfect sense in a business or businesslike environment because these environments will be completely unoccupied overnight and have air conditioning, which usually does a daily fresh-air purge, ensuring that the sensor will have regular exposure to fresh air.
However in a residential environment, the auto baseline calibration often doesn't make sense, especially in winter. When the windows are closed and/or people or pets are around, it's very rare for the sensor to see uncontaminated fresh air, so it will see say 500ppm of CO2 and assume it's fresh air when it really isn't. I have measured this and it's a real problem.
In a residential environment, unless you're sure you have good, frequent exposure to pure fresh air, you're better off doing a fixed calibration once a year or so.
AirGradient also seems to be a hardware-only design. The ESPHome project [2] has great software support for a variety of sensors (including the SenseAir S8, so it should be compatible with the AirGradient hardware) as well as a very well-documented hardware project [3]. After trying my own Arduino-based software and then ESP-IDF, I find esphome much more pleasant to work with.
Any CO2 sensor (part) that gives you the ability to turn off ASC should work just fine and most of them do, you just need to trigger it.
Personally, after trying out a bunch of sensors, I use the Sensirion SCD30.
As for devices, I'm not aware of a consumer device that I'd recommend. If you're willing to do at least a little bit of DIY, Watterott [0] sells an SCD30 hooked up to an Arduino-compatible MCU with WiFi, a red/green/blue indication of CO2 levels and ASC disabled by default [1].
It's an open-source hardware design and software [2] and has a few reference firmwares [3], including one [4] for MQTT.
If you want to go a little bit further, I'd recommend an ESP32 with an SCD30 and ESPHome [5]. That's what I use myself, mostly because I already had the sensors prior to Watterott's product existing.
I appreciate your DIY instructions, but I really dislike how your website goes through the effort of hiding what you actually sell and also how much it costs. I don't want to "contact you" to get that information. We've been long enough in the 21st century that it has become an adult, and still I keep running into this archaic nonsense.
For example, you mention your "sensor package" in the FAQ and that's it. Your DIY instructions mention the "AirGradient PCB", _but there is no place where I can buy it_. For the love of god, put a 'buy' button on your website.
Usually this means the company does not sell to consumers and is b2b only, similar to how you just can't buy something anonymously online from a wholesale distributor.
Volume sales “for homes”means apartments (or condos). “For Homeowners” is a different market. Usually there will be a different website for that market. It will need to mitigate “the customer is always right” attitude prevalent among consumers.
It might not be worth it to organize a big order nowadays, PCB fabrication is already super cheap. JLCPCB (and others, but I have the most experience with them) will do 5 boards for $2 + shipping and the first order gets free shipping. I've used this service for prototyping many times and had great experiences.
I had been planning to build almost the exact same thing as what the parent posted but had been putting it off because I didn't want to draw up a PCB, so this is perfect.
They want to change what they charge from time to time so putting a price up front will force them to leave money on the table. Not gonna happen. Contact them instead.
Instead of contacting them, I will spend a little time investigating whether there's someone else I can buy from, who doesn't consider being "forced to leave money on the table" makes this a reasonable way t treat potential customers, and will choose to spend money at a less customer hostile business - or possibly do without the product.
Contacting some random "enterprise sales" team? Not gonna happen.
Increasing friction is increasing friction. The GP wants to reduce friction, and your proposal likely doesn’t do that for the majority of potential customers.
That said, too many people (myself included) are so used to being courted as a customer (or really, user to try and upsell to or datamine from) that we’ve forgotten that not everyone wants our business and custom.
Splashing some cold water on your face and reminding yourself that you’re not the centre of the universe from time to time isn’t a bad habit to reduce behaving like entitled children. I still struggle with this, but baby steps... (pun not intended)
This. I no longer have access to a soldering iron and want a bunch of these, not enough that it's worth the cost of buying equipment and the time spent making them.
It looks like you're using a Plantower PMS5003. I have one of those hooked up to a Raspberry Pi and it works well but I also built a few of these with ESPs: https://sensor.community/en/sensors/airrohr/
They support the PMS but I used the default SDS011. They both seem reasonable for relative values but I'm not sure about the accuracy without proper calibration. They don't appear to give similar readings to my Plume Flow 2: https://plumelabs.com/en/flow/
https://www.airgradient.com/diy/
We have tested it extensively and it is very accurate for the fraction of the costs of commercial sensors. You can build it for less than USD 20 and send the data to our cloud server or any other backend.
We also measure CO2 because if you have purifiers running you often do not have enough fresh air ventilation and your CO2 often gets very high (often >1500ppm) causing headaches and reduce cognitive performance.
We measured this in classrooms some time ago and the results were not very good.
Details. https://www.airgradient.com/blog/2020/02/07/we-measured-the-...