I Found the Best Way to Monitor Indoor Air Quality This Winter - CNET

Article updated on November 2, 2024 at 5:00 AM PDT

SwitchBot's affordable Meter Pro can check CO2 levels, humidity and more in any room -- and showed me surprising info about my own home.

CNET’s expert staff reviews and rates dozens of new products and services each month, building on more than a quarter century of expertise.

SwitchBot's Meter Pro is the most affordable CO2 monitor we've found.

At CNET we're happy to recommend carbon monoxide detectors, air purifiers and dehumidifiers. But there's a key question to ask beforehand: What is the air quality like in your home?

Most homeowners don't know. Unless something drastic happens like a health incident, it's hard to tell if there's too much CO2 (carbon dioxide) in the air or if your home is suffering from a humidity (or lack thereof) problem. So how do you find out if your air needs help?

SwitchBot has one of the most affordable, standalone air-quality monitors I've seen. While many security systems include air quality monitoring add-ons, they're part of a larger, more expensive kit. You can use SwitchBot's monitor without any additional purchases (adding a mini hub is optional for more app features), move it to any room in your home, and choose how often it updates. Best of all, you can find it for just around $50.

As I tested the Meter Pro with CO2 monitoring, I found some air quality surprises in my own home, learned what the app can do, and was surprised by how easy the smart meter was to use.

The SwitchBot Meter Pro works well alone or with other smart devices.

Switchbot's Meter Pro with CO2 monitoring can work indoors or outdoors (or both with the right add-on), but the CO2 feature makes it a much better indoor option. You can also move it to specific spots where you're worried CO2 may be higher. The monitor works by showing you parts per million, a common method to measure CO2 particles in the air, and updates itself regularly. Housed inside is an NDIR Swiss monitoring sensor, and it appeared to be very accurate during my testing.

If you are using the standalone device, it's effortless to set up. I unboxed the meter, pulled out the battery tab to activate the battery, and it immediately started displaying nearby air quality.

You'll note in my photos that by default the temperature appears in Celsius, but that's no problem. A small button on the top of the meter let me switch between Celsius and Fahrenheit instantly. The hardest part was deciding where to put it.

SwitchBot's Meter Pro gives you all the details about your room's air quality.

During testing I moved the SwitchBot Meter Pro frequently, positioning it on various counters and tables to see how it changed. I quickly learned the CO2 levels in my home were close to the maximum acceptable level -- anything above 1,000 PPM and it's time to consider making changes like more ventilation or air purification. That's where our lab-tested recommendations can shine.

The high numbers weren't entirely surprising. When I tested, we were in the tail end of smoke season here on the West Coast and the air outside was still relatively smoky, something that has a major impact on CO2 levels, even indoors. Also, my home uses natural gas for both fireplace heating and cooking, another factor that bumps up CO2 numbers.

As regional fires died down, air quality in my home notably improved, with PPM declining to 600 to 700 PPM. It was even better in some other homes where I brought it for a quick test, indicating there may still be work for me to do to improve air quality.

In addition to temperature and CO2 levels, the meter monitors humidity (my ranges in the high desert were pleasantly comfortable during the wetter fall season) and shows you the current weather. That makes it a nice hub for a quick view of what's going into your lungs.

SwitchBot's app provides a plethora of information.

Connecting the app via Bluetooth opened a world of possibilities -- well, once I created an account and applied numerous firmware updates, anyway.

Using the app, I could adjust how often the meter updates to save on battery life. The battery is rated for around 12 months of use and recharges via USB-C, so it's not a major issue. But I found increasing the frequency of updates let me test air quality more easily with no noticeable drawbacks.

You can use the Meter Pro as is, but it gets a sizable functionality boost with the SwitchBot Hub Mini ($40). My model came with one, so I was able to set it up and connect the SwitchBot app. That enabled some of the more advanced features like notifications and remote monitoring, so it's a quality-of-life improvement if you want to spend a bit more.

With the hub, the app also lets you set alerts, either via notifications or with sound alarms, based on triggers like when the temperature, humidity or PPM reaches certain levels. That also lets you do things like get low temperature alerts in rooms (or garages) that are distant from your thermostat so you know when they may need extra heating.

SwitchBot's preferences allow for lots of readout customization.

The SwitchBot app isn't quite finished yet. As I discovered, you can view the local dew point and vapor-pressure deficit, as well as get weather forecasts if you're willing to provide the app with your address. The app includes a history chart so you can see patterns over time, too.

Deeper into settings, even more options emerge. You can recalibrate the temperature and humidity settings if they seem a bit off for your climate, then manually adjust your idea of a "comfort" level to control when the monitor warns of a problem.

The Hub Mini also provides compatibility with common voice assistants, such as Amazon Alexa. That allows you to set up automations with other Alexa-compatible devices, like a smart thermostat or even a humidifier.

While the app does mention the ability to store your long-term air quality data in the cloud for a fee, there's absolutely no need to do this if you are only using the Meter Pro, so subscriptions aren't a concern for this monitor.

SwitchBot's Meter Pro with CO2 monitoring is compact, highly portable and accurately measures air conditions in any part of your home with its Swiss-made sensor. Add in the current low cost of $50 to $60 and it's an ideal monitoring solution for anyone who isn't sure what the air is like in their home and wants to keep an eye on air quality this winter.

One last note: If you're interested in purchasing this air quality monitor, make sure you're choosing the option with CO2 monitoring. SwitchBot has a similar Meter Pro that does everything but monitor carbon dioxide levels. The new version with CO2 monitoring is a much better package, even with the higher price.