I want to add a few more monitors to this list. Firstly, a couple of devices deserve a mention at the top end of ‘affordable’ (around $100).
1. The Qingping Air Monitor Lite.
I mentioned this monitor’s sibling in the initial post, but I think it’s unfair to overlook the Qingping Air Monitor Lite as this device is also very popular. While it doesn’t have the same battery life and portability as the Qingping/Smartair CO2 monitor, this monitor also measures other pollutants - namely, PM2.5 and PM10.
While I don’t trust PM10 readings from any low-cost sensor, I appreciate the addition of a PM2.5 sensor, which makes this device more well-rounded than a CO2-only monitor. With that said, you will lose some of the strengths of Qingping’s dedicated CO2 monitor, such as its portability (this monitor only has an eight-hour battery life).
While the sensors used on these monitors can vary (depending on availability), they use CO2 sensors from SenseAir or Sensirion, trusted brands with good reputations. While the PM sensor is a bit less tried and tested (it’s from Grandway), I’ve found it accurate enough.
2. CO2.Click Model F
The CO2.Click Model F is a cheaper alternative to the much more pricey Model C. While I haven’t used this monitor yet, I love using the Model C, which shares many similarities with the more expensive device.
At $129 CAD, the Model F is a bubble-gum stick-sized CO2 monitor that uses a Sensirion SCD41. While I initially had some doubts about the sensor, those were cleared up after this discussion. I now believe it to be a great CO2 sensor.
This monitor has around 15 hours of battery life, meaning you can easily get through the day, but you must charge it every night. While this isn’t ideal, there are always trade-offs to be made at this price point, and in return, you’re getting a fantastic sensor.
If you’ve tried the CO2.Click Model F, please feel free to share your thoughts, as I would love to hear more about how the device is for daily use.
3. Other affordable monitors.
I’ve also recently come across the below monitors, but I have no idea how they perform. They both have NDIR sensors, so they should be accurate: