Aeropulse A200-CO2 Review – Is This the Best Indoor CO2 Monitor?

If you’re a bit of an air quality nerd like me, there are occasionally new sensor releases that are very exciting. Last year, the tiny Bosch BMV080 PM2.5 sensor announcement was incredibly exciting. This year, the thermal conductivity STCC4 was potentially something that could transform the industry (unfortunately, after testing, it doesn’t hold up very well). Another of these very exciting sensors was announced earlier this year – the Senseair S12.

The S12 is unique not because it’s transformative in regard to the technology it uses – it’s still the same ‘old’ NDIR technology – but because it is a substantial step forward in terms of size and power consumption at the price point it’s targeting. It’s not introducing any fancy new technology, but it’s improving on what has become the gold standard of CO2 sensing.

A few months ago, Senseair was kind enough to send me an S12 for testing, and I’ve been awaiting the day when I begin to see this sensor being used in monitors. As it turns out, I didn’t need to wait long at all, as Ken from Aeropulse reached out to me to let me know about their new A200-CO2 monitor – the first (that I’m aware of) to be housing the new Senseair sensor.

Needless to say, I was quite excited to test the A200-CO2. However, while my excitement initially was due to the new sensor used within the device, a few other aspects have popped up during my time with the device that have added to my excitement over this new device. So, with all of that said, let’s dive in and see exactly where the Aeropulse A200-CO2 sits and whether it’s a device you should consider.

Contents

Accuracy & Sensor

The S12 (bottom) and an ‘typical’ NDIR sensor.

No air quality monitor is worth your time unless the foundation upon which it’s built is accurate. This leads us to the sensor – the Senseair S12, which I’ve already probably discussed too much. Senseair is a leading company in the field of sensors, and they’re particularly famous for their range of NDIR CO2 sensors. So, while the S12 is still largely untested and this is my first time trying the new sensor, I was already confident going into this review that the Aeropulse A200-CO2 would be an accurate monitor.

The S12 was announced at the beginning of this year, and it’s classed as an ‘ultra-compact’ ‘true NDIR’ CO2 sensor. It provides the same accuracy specifications as Senseair’s flagship Sunrise/Sunlight series (used in devices like the Aranet4 Home) in a package that is approximately 75% smaller in volume. Until this sensor arrived, monitor manufacturers had to make a decision – they could either opt for an NDIR sensor, which is the gold standard of CO2 monitoring, or for something smaller like a photoacoustic sensor. The issue is that the photoacoustic sensors – while accurate enough for the typical consumer – have never quite reached NDIR performance in terms of accuracy, and they have some significant caveats.

While the S12 is still a bit larger than the current generation of photoacoustic sensors, it’s small enough and draws so little power that it can be used in ultra-compact, battery-powered devices. All of this without sacrificing accuracy. Personally, I think the next generation of ultra-small monitors like the AIRVALENT CO2 monitor and AirSpot will likely be powered by this sensor.

Anyway, before I digress too much, the S12 is a sensor that is currently relatively untested and unvalidated due to its newness to the market. AirGradient did a comparison and selected the S12 for the AirGradient Go due to its impressive performance, but there is little in the way of formal, third-party testing at the moment. However, considering Senseair’s expertise in this field, I dare say it will be a very good performer and sit amongst the best consumer-grade sensors on the market.

Spec	Senseair S12	Senseair Sunrise	Senseair S8 LP	Sensirion SCD43	Sensirion STCC4
Principle	NDIR (LED)	NDIR (LED)	NDIR (lamp)	Photoacoustic	Thermal conductivity
Accuracy	±(30 ppm + 3%)*	±(30 ppm + 3%)	±(40 ppm + 3%)	±(30 ppm + 3%)	±(100 ppm + 10%)
Range	0–5,000 ppm	400–5,000 ppm	400–2,000 ppm	400–5,000 ppm	400–5,000 ppm
Size	18 × 15 × 6 mm	33.5 × 19.7 × 11.5 mm	33.9 × 19.8 × 8.7 mm	10.1 × 10.1 × 6.5 mm	4 × 3 × 1.2 mm**
Avg. current	<34 µA	~34–38 µA	<18 mA	15–18 mA	~1 mA
Operating range	−10–60 °C	0–50 °C	0–50 °C	−10–60 °C	10–40 °C
Lifetime	>15 years	>15 years	>15 years	>10 years	10 years

Manufacturer datasheet figures, September 2026. *At ASHRAE test points; ±(50 ppm + 3%) across the full 0–5,000 ppm range. **Excludes the separate SHT4x sensor the STCC4 requires. Average current is in each sensor’s default/continuous mode; the SCD43 and STCC4 drop to ~0.5 mA and <100 µA respectively in single-shot mode.

As you can see above, the S12 is essentially Sunrise-level (Senseair’s top of the line) ultra-low power consumption and accuracy at a far smaller volume. In terms of stated accuracy, it also sits ahead of the Sensirion SCD4x photoacoustic series (but the SCD43 is shaping up to be a significant improvement in this regard), and draws vastly less power, but it is still slightly larger.

While it’s nice to look over spec sheets, I was curious to see how the S12 and A200-CO2 that it’s housed within would compare to my other carbon dioxide monitors. Now, for context, this is not a scientific comparison by any means, and it was more just to confirm what I already guessed – the readings would be virtually the same as previous Senseair sensors, which are known to perform well.

As it turns out, yes! That is exactly the case. When compared to the S8 (used in the AirGradient monitor) and the Sunrise sensor (used in the Aranet4 Home), the S12 provides almost identical readings. Interestingly, while the Aranet4 Home with the Sunrise appeared quite noisy, both the S12 and S8 exhibited less noise at a 1-minute resolution (the highest possible exportable resolution from all three monitors). I believe this may be due to the fact that the Aranet4 was taking single-shot readings due to being on battery, but that’s just a hypothesis.

If anything, this comparison made me more curious about the Aranet4 Home performance. Regardless, it seems that the S12 is a good performer and keeps up with what we expect from an NDIR sensor from Senseair. While I wasn’t able to graph my results, I also compared the A200-CO2 to the S12 by itself on a developer board and got very consistent results between the two at ranges between 400 and 4000 ppm. I also have many more weeks’ worth of test data, but it’s not particularly interesting as the devices were consistently showing results like those graphed above.

As with any carbon dioxide monitor, calibration plays a big part in the overall accuracy of the device. Below is a graph showing the same three monitors before they were co-located and calibrated. That leads me to one key point about the A200-CO2 – you can’t force a manual recalibration. I really hope this feature is added in the future, but for now, the device relies on ABC.

Temperature on the A200-CO2 was consistently about 1-1.5 degrees Celsius below a hygrometer that I used for comparison, and relative humidity usually sat within ±3%. While the device shouldn’t be used as a reference for either of these metrics, it’s more than accurate enough to give you insights into the trends in your indoor environment.

Overall, the accuracy of the A200-CO2 is very good. However, that’s very much in line with what I expected going into this review! Temperature and humidity values aren’t perfect, but they’re accurate enough to be used to make informed decisions.

Design

The Aeropulse A200-CO2 is a relatively flat device that is intended to be either mounted on a wall, or sat on a bookshelf or desk. Emphasising this are two of the accessories contained in the box – a wall mount and a wooden stand for the device. I’ll come back to these later, though. For now, let’s focus on the device.

If I’m honest, when mounted on the wall, the A200-CO2 looks almost like a control panel for an HVAC system or air conditioner. Considering the target market, this is a great approach, and I can imagine this blending in very well at a school, hospital or office building. Even in our home (which has white walls), the device blends in very well and looks good.

The mounting plate that comes included.

However, for most of the time that I’ve been using the device, I’ve had it sat on either my desk or bookshelf. This is largely due to the fact that I’ve been moving it around the house a lot for testing and comparison purposes, but the included wooden stand really makes it quite aesthetically pleasing to sit somewhere and refer to when needed.

The front of the monitor is dominated by a large screen that shows the current CO2 concentration in ppm, temperature and relative humidity, and some status icons for Wi-Fi connectivity, battery life and reading interval. The screen is quite large, and it’s easy to view from across a room. I appreciate how easy to read the screen is. If it’s dark, or if you want an even quicker indication as to what the current air quality is, there’s also a small LED bar above the screen which lights up in traffic light colours depending on the current CO2 concentration the monitor measures.

While the device identifies six different CO2 bands (from excellent to critical), the LED only has the three traffic light colours, and these are tied to the three initial levels. That is to say, green will show at ‘excellent’, orange will show at ‘good’ and red will show at ‘fair’.

Controlling the device is done via an orange button located on the top-right of the device. This is the only button, meaning most settings are locked behind a sequence of button presses. Below you can see what every combination does. Notably, there is no way to manually calibrate the sensor through button presses (although a factory reset may do this).

• Long press: turn the device on and off
• 2 presses: toggles between temperature units
• 3 presses: enables Bluetooth for pairing with the mobile application
• 5 presses: cycles through measurement intervals (1, 5, 15, 30 and 60 minutes)
• 7 presses: turns the buzzer on and off
• 8 presses: deletes the current alert setting
• 10 presses: turns the LED light on and off
• 20 presses: factory resets the device

On both the top and bottom of the device are vents to ensure that air can enter the device for measurement. Notably, at the bottom of the device is also a USB Type-C port, giving users the flexibility to use this plugged in (in which case the device has a 1-minute measurement interval), or on battery (6x AA batteries with a lower measurement interval). I appreciate this flexibility, and giving users a choice is always appreciated. With that said, since the device uses AA batteries, there is no way to charge them.

Aeropulse advertises up to 500 days of battery life on the A200-CO2, but this is only if you use very high-capacity batteries and lower the measurement interval to once per hour. I’ve had my device use 30-minute intervals with 6x Eveready Super Heavy Duty batteries, and I have one bar of battery left after around two months. This isn’t bad by any means, but it’s a far cry from something like the Aranet4 Home. My suggestion for this device would be to use some rechargeable AA batteries, as you will be changing them frequently enough that the additional investment is worthwhile.

As mentioned earlier, this device is not meant to be used portably, but I’ve included an image below showing what it looks like in my hand. With that said, I love the inclusion of the wooden stand and mounting bracket, as they make it very nice to use this monitor anywhere indoors.

Overall, I like the design of the A200-CO2. It’s a simple-looking device, but that’s to its benefit. It looks at home on a wall, and the included stand also makes it easy to sit on a desk or bookshelf. My only real complaints with the design are the inability to trigger a manual calibration from the device itself and the fact that the battery cover isn’t a snug fit, so it moves around a bit whenever I pick up the device.

Connectivity & Application

The Aeropulse A200-CO2 connects via Wi-Fi, but where most air quality monitors are stuck in the slower 2.4 GHz band, the A200 supports both 2.4 GHz and 5 GHz. This is a relatively minor improvement in the scheme of things, but it’s one that I appreciate. While I still need the 2.4 GHz band for a range of other devices, I dream of the day that I can disable it.

If you are running the A200-CO2 on battery, it will send data to the dashboard & application hourly, meaning you won’t be able to see recent data unless you check it right after it updates. However, when it does upload data, you will get all the data recorded over that time. If you use the Type-C connection, data uploads much more frequently, and you will be able to see live data (1-minute resolution).

Currently, there are no subscriptions (at least for users like myself with only a single monitor or a few), and you can choose to use either the iOS and Android applications or the web dashboard. Let’s start with the web dashboard first, because that’s what I’ve found myself using more often due to it being the easier way to view long-term data.

When you log in to the cloud portal (which uses the same details as the application login), you will be met with a screen that shows your monitors. This is the ‘Devices’ tab, and it shows every device connected to that dashboard and their current readings. By clicking on any device, you will go into the analytics view, which shows you time series graphs of the selected pollutants over the selected period (last hour to last 30 days with the ability to customise the period). You can also compare two different pollutants/parameters at the same time.

Hourly data is shown at a 1-minute resolution (if the device is plugged in), while other data is binned. 12- and 24-hour data is shown at a 15-minute resolution, and anything more than that is displayed hourly. Overall, I think this is a good balance, and the graphs are fast and responsive.

While the graphing screen allows you to compare two pollutants from the same device, the second screen, ‘Compare’, is where you can view data from different monitors. In my case, I wasn’t able to test this screen as I only have a single monitor, but this would be useful for any larger deployments monitoring multiple rooms in a building.

The third tab allows you to create email notifications that are entirely customisable. I like the flexibility here, and you are able to create anything from an alert when CO2 matches or exceeds 1000 ppm to an alert when the temperature drops below 20 degrees.

After this you have an export screen which – as the name suggests – allows you to export data. You can select the data period you want to export, and an email with the data will be sent to you. It’s worth noting that this export will be tied to the measurement intervals of the device, so if it’s on battery reporting at a 15-minute resolution, that’s all you will be able to export. If you want 1-minute resolution, the device will need to be plugged in.

The final tabs are ‘Kiosk View’, ‘User Setting’ and ‘Deployment’. User settings house a few basic settings for the dashboard (such as what units you want displayed), but all device settings can only be accessed via the device itself. Deployment looks to be for MQTT deployments (the device supports MQTT), and Kiosk View allows you to create a unique URL that can be displayed on any device with a browser to convey air quality information. This would be great to show on a screen in a public area of something like an office building.

Moving on to the app, we have a similar feature set here minus the ability to export data and set up Kiosk View. That is to say, while you can view data here and set some basic display settings, there is nothing you can actually change on the device itself – no manual calibration, display settings, ABC settings, or otherwise.

Personally, I would love to see a few more settings either here or on the dashboard (or both) allowing users to at least manually force a calibration. It would also be nice to allow users a bit more customisation with the device LEDs and to be able to control measurement intervals without touching the device itself. Either way, both the web dashboard and app are responsive and fast, but I do hope some more features are introduced in the future.

Pricing & Competition

The Aeropulse A200-CO2 doesn’t have a price listed on the website, but I’ve been told by the founder that it sells for 109 USD. The A200-CM, which includes PM, tVOC and NOx data, on the other hand, goes for $169. At first, this seems like a tough sell, as $60 for those extra parameters seems like an easy up-sell. When you consider the pricing of other monitors with similar parameter coverage (think of AirGradient at $230 and Airthings at $300), the $169 A200-CM seems like an easy choice.

However, $109 for a CO2-only monitor seems like quite a poor deal in comparison. Or so it seems at first thought, but I don’t necessarily think that’s the case. If we look at the product page of the A200-CO2, it’s clearly focused on the healthy-building market, as it holds certifications like WELL and REACH, which are only meaningful in these industries. If we then look at the monitor specifications and the dashboard, it becomes clear that this isn’t trying to compete with a consumer device like the Aranet4 Home, but rather with something like the Aranet4 Pro or the business offerings from Atmo or uHoo. Compared to these devices, both the Aeropulse A200-CO2 and A200-CM are actually very affordable options.

Now, while I think it’s clear that the Aeropulse catalogue is targeting the B2B side (as is evidenced by the lack of a price on the website) and I think it’s likely a very compelling option there, I’ve been using it as a consumer and want to speak on where it stands for a normal person looking for a CO2 monitor for their home. Well, in this case, I think it holds up quite well too.

This isn’t a portable monitor that you will be taking out and about with you. It is portable in theory, but the lack of Bluetooth connectivity and size mean it’s less than ideal in this role. Rather, this device is at home mounted to the wall in your living room, or sitting on your office wall. For this reason, this is a device more akin to something like the Sensibo CO2 monitor or the Honeywell Home Air Quality Monitor. In this regard, there aren’t too many direct competitors in the same price range within the consumer space.

Now, it is possible to get cheaper carbon dioxide monitors, and something like the Qingping CO2 monitor offers good battery life, Wi-Fi connectivity, and decent accuracy at a slightly lower price point (around $80), but it’s still not a directly comparable monitor. The A200-CO2 has a more robust platform (for desktop), much longer battery life, a best-in-class sensor, and a far larger screen with a notification LED.

Therefore, I think the pricing for the A200 is very reasonable (I went in expecting this to be a significantly more costly device). If you’re looking to deploy many monitors around a building, these are absolutely worth looking into. Even if you just want a CO2 monitor for your living room, the Aeropulse devices provide Aranet-level accuracy at a lower price. Of course, the biggest trade-off is portability.

To me, the real question is whether upgrading to the A200-CM is worth it or not. The A200-CM also uses the S12, and it also adds a Plantower sensor for PM and an SGP41 for tVOC and NOx. For $60 more, you’re getting a significantly more well-rounded indoor air quality monitor for around a 50% price increase. For some people, this extra cost will be worth it, but if your focus is CO2 in an indoor space, the A200-CO2 is worth your consideration and has a reasonable price.

Conclusion

So, with all of this said, where do I stand after using the A200-CO2 for a couple of months now? Well, it’s a device that I quite like, and it’s one that I will continue to use. In my case, it’s the ideal monitor to have mounted on the wall in our living area to give insights into ventilation.

For the general consumer, I think this device might be hard to justify. At $109, it’s in the middle range of consumer-grade CO2 monitors. However, it doesn’t come with the portability that many of them do. With that said, it’s just as accurate as something like an Aranet4 Home, which is significantly more expensive, so if a static monitor is useful for your use case, this is perfect. However, I do think that the A200-CM will be a popular device, as it’s just $60 more and covers a much wider range of parameters while keeping the same CO2 sensor.

However, for any school, hospital, office, building, or even a house, the Aeropulse monitor makes a lot more sense. You can mix and match the CO2-only A200-CO2 with the A200-CM and cover multiple rooms at a far lower cost than what most other platforms would allow. If you look at the Aranet Pro lineup, Atmocube, uHoo, or AirGradient platforms, you would be spending significantly more for the same number of monitors. This is where I think the Aeropulse devices make the most compelling choice.

I would like to see more features added to the app and web dashboard, as I believe it should be possible to fully remotely control the device. At the very least, I would like to see calibration features built in here, and I hope those get added in the future.

However, for anyone looking for a stationary indoor air quality monitor, I think the A200 series makes a lot of sense. I quite like the A200-CO2, and this will remain mounted in our living room for the next few years, I’m sure. Who knows? I’d be interested in adding a few more of these devices around the house too!

Aeropulse A200-CO2 FAQ