Have you ever walked into a room and noticed it felt "stuffy"? While looking to analyze indoor air quality, I scoped out what I found to be the best solution: the Netatmo Weather Station (NWS). I didn't find any good pictures via Google Image search at the time in relation what the Web UI looks like for what was important to me (CO2 levels). The NWS base station comes with the central unit and an outdoor unit. You can expand the system with up to 3 additional expansion modules. There is a slight issue with the humidity sensors in the base unit, both the indoor and outdoor units; however, you can contact support and have them re-calibrated-- you can find more information on Netatmo's forums or other websites that sell this product.
- The first, tallest module is the "main" module that communicates with all other devices.
- The middle module is the outdoor module which has been designed to be able to survive outdoor conditions.
- The third module on the right is one of the expansion modules you can purchase.
Overall, setting up with iOS was a breeze, the user manual is simple and easy to understand . One tricky thing that some folks had asked was how to pair the 3 additional modules? In that scenario, you'll actually attach the device via USB to your computer, traverse the Web UI and you'll download an application if using Windows that will allow you to pair the device. It is also noted in the forums that the master module and the expansion module should be right next to each other to ensure a successful pairing. Once they are paired, the expansion modules can be moved around your living space.
Why would you care about CO2 levels anyway?
To quote Wikipedia :
"To eliminate most Indoor Air Quality complaints, total indoor carbon dioxide should be reduced to a difference of less than 600 ppm above outdoor levels. NIOSH considers that indoor air concentrations of carbon dioxide that exceed 1,000 ppm are a marker suggesting inadequate ventilation. The UK standards for schools say that carbon dioxide in all teaching and learning spaces, when measured at seated head height and averaged over the whole day should not exceed 1,500 ppm. The whole day refers to normal school hours (i.e. 9:00am to 3:30pm) and includes unoccupied periods such as lunch breaks. European standards limit carbon dioxide to 3,500 ppm. OSHA limits carbon dioxide concentration in the workplace to 5,000 ppm for prolonged periods, and 35,000 ppm for 15 minutes. These higher limits are concerned with avoiding loss of consciousness (fainting), and do not address impaired cognitive performance and energy, which begin to occur at lower concentrations of carbon dioxide."
Where is the Web UI?
Web UI screenshot of what the dashboard looks like, it is customizeable and can be re-arranged to your liking, in the screenshot below I am only concerned with the CO2 readings in Parts Per Million (PPM).
Click the image to see the full size dashboard using the maximum of 3 expansion modules.
What impact will this have on my network?
The average is 10-23 bits per second (bps) back and forth with the Netatmo server, this is shown below by using munin and custom iptables firewall rules to grab these metrics:
What about CO2 sensor accuracy?
To confirm the accuracy of this device, I verified the readings with another vendor's CO2 sensor. I compared the Netatmo's readings with a SUPCO IAQ50 and they are generally with in +/- 50PPM of each other. Overall, I am happy with the Netatmo and it brings another set of monitoring tools and metrics for your home environment.
The SUPCO is located near the main unit, note: the picture below was not taken at the same time as the screenshot/Web UI above. The Netatmo was reading 542PPM with the SUPCO reading 572PPM; however, they are at slightly different elevations.
What does it cost?
The Netatmo Weather Station (NWS) retails for $179 which includes the main module with an outdoor module. The expansion modules go for $79/each. However, there are often discount codes during the holidays that can help to bring these prices down.
The Netatmo Weather Station offers more than is described here, it provides user-defined push-notifications for all of its sensors, including audio volume in decibels; however, that is on the main unit only, none of the external or expansion modules contain a audio microphone/sensor. In addition to sensor-specific notifications, the Netatmo also pushes storm and weather alert notifications relevant to your area. Another great feature I found is if your wireless cuts out or you are performing maintenance-- from what I've seen initially the unit will backfill the metrics once it reconnects so there should not be any gaps on the graphs.
I was not given any product or asked to perform this review, I was interested in air quality and environmental monitoring, such as the temperature, humidity, CO2 and ambient noise, thus far, nothing beats Netatmo for this functionality. Could you do it for cheaper with your own components using a Raspberry Pi? Probably, but there would be a lot more needed for the iOS integration piece and storing the data in the cloud.