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Welcome back to The Air Quality Index! This issue reached you later than I wanted, but there’s a reason for that. I've spent the past week or so rebuilding the BreatheSafeAir website, and it's now live. If you've got a spare minute, head over and have a look. I'd love to know what you think, whether you like it or reckon I've made a terrible mistake. I read every reply, and appreciate the feedback.

Anyway, on to this issue itself. I've been noticing a trend lately, and it’s one that’s becoming increasingly common. Smart products are creeping into every corner of the home, and air quality monitoring has been swept up with them. Whatever ecosystem you've settled on, Apple Home, Alexa, Google Home, Homey, Home Assistant, there's now an air quality monitor designed to slot into it.

What I find most interesting, though, is where these monitors are coming from. The market has quietly split into two camps. On one side sit the dedicated air quality companies, the names that have been at this for years and tend to focus on sensor accuracy and reliability. Think AirGradient, PurpleAir, and IQAir. On the other are the sensor and IoT companies, smart home brands that have added an air quality monitor into their lineup to round it out and give you one more reason to stay in their world. I touched on a bit of this last issue when IKEA and Amazon came up, but the more I look, the more brands I keep finding doing exactly the same thing.

Most people know Govee as a smart lighting brand. That's certainly how I knew them, with their colour-changing strips and lamps turning up all over the place. They're an IoT company at heart, so when WIRED named the Govee Air Quality Monitor their pick for the best budget PM2.5 monitor, I was sceptical (also, I don’t have much trust at all in WIRED when it comes to such claims). A $35 device from a company I associate with mood lighting didn't fill me with much confidence. I bought one anyway to find out for myself, and it's been running in my office for about five months now.

What caught me off guard was the accuracy. For roughly a month I had it sitting next to a factory-calibrated AirGradient ONE, and the two tracked each other so closely that I'd convinced myself they must share a sensor (they don't, as it turns out, as the Govee uses a Cubic PM2008MS instead of a Plantower). Most of the time they sat within 2 to 3 µg/m³, often landing on the exact same value. It’s fair to say that I was surprised with the design, too, because while that fabric loop on the side looks purely cosmetic, it actually houses the temperature and humidity sensor, tucked away from the heat the internal electronics give off. It’s surprisingly well thought out. There are rough edges, like an app that feels bloated when this is the only Govee device you own, and Alexa integration I never got working properly for PM2.5 but at this price, though, these flaws are easy enough to forgive.

I dig into the full accuracy data, the teardown, and how it holds up against the IKEA monitors in the complete review over on the site. You can read it here.

If one device has stayed stubbornly analogue, it's the smoke alarm. No way to hush them from your phone and no link to anything else in the house. For this reason, the Sensereo MS-1 caught my attention as it’s been billed as the first native Matter-over-Thread smoke alarm. Matter means it drops into whatever you're running, Apple Home, Alexa, Home Assistant, Google Home, without being chained to one ecosystem. It's a certified alarm first (EN 14604, tested by TUV Rheinland) with the smart features sitting on top. Don’t worry, it still functions as a ‘dumb’ alarm too and all connectivity systems are isolated from the core functions (there are even seperate batteries for each).

Is a smart smoke alarm really that useful, though? Well, that’s for you to decide. Push notifications if it goes off while you're out is one obvious benefit as it might allow you to take action faster than you otherwise could. I can also test it from my phone, which has been more useful than it sounds, since our living room ceiling sits around 4 metres up and reaching the alarm normally means dragging out a very long ladder that doesn’t feel very safe to use. Beyond that, you can wire it into automations, so smoke could cut power to your HVAC or throw every smart bulb to full brightness to help you get out in the dark. As I mentioned, if the network drops, it falls back to a normal alarm and keeps detecting smoke regardless.

The biggest limitation with the device currently is that it’s only certified to the EEA standards, meaning it’s focused on the European market and should not be used anywhere that relies on different standards (such as the U.S). I get into the certification side and how the smart features actually behave across each platform in the full review here. The MS-1 handles smoke only, so if you've got a gas boiler or a wood stove, you'll want carbon monoxide coverage too. That's the MSC-1, the smoke and CO version, and I'll have a full review of that one up before long.

Fair question, and a reasonable one to ask after a section on a smoke alarm whose smart features you'll hopefully never have a reason to use. Air quality monitors sit at the opposite end of that spectrum. A smoke alarm stays quiet for years, but a monitor is generating data all day, and that data is something you can act on. Of all the devices quietly going smart, this is the category where it makes the most sense to me.

The clearest example is what happens when you pair a monitor with an air purifier. Most purifiers sold now come with some sort of smart function and an onboard sensor running an "auto" mode. The problem is that the built-in sensor tends to be one of the cheapest parts of the whole device, and I usually don't put much faith in it. A monitor you actually trust can do that job far better. Feed its PM2.5 readings into an automation and the purifier switches on when the air turns bad, reacting to a sensor you've got confidence in rather than whatever the manufacturer tucked into the corner of the unit. I run these automations at home, and, most of the time, I forget they’re even running.

It stretches well past purifiers, though. For example, with CO2, where a reading climbing past 1,000ppm can nudge a fan or ventilation system into gear, or simply ping your phone to go crack a window open. The same idea works for humidity kicking a dehumidifier on in a damp room. Then there's the data itself, and this is where a platform like Home Assistant becomes invaluable. Most manufacturer apps hand you a rolling few days of history and not much more, whereas pulling a monitor into Home Assistant lets you log readings as far back as you like and graph one room against another, turning up patterns you'd never spot glancing at an app. For anyone who enjoys picking through their own data (I’m guilty!), it's hard to overstate how much more a monitor gives you this way.

One last thought before I go.

As all these brands pile into air quality, most run through their own apps and servers, and that's fine right up until the company loses interest. Google discontinued the Nest Protect back in March 2025, and anyone who built their setup around it is now on a clock. This is a quiet argument for Matter and Thread, since a device that speaks Matter isn't locked to one platform and can migrate to another system if an ecosystem disappears. Going fully open, like Apollo, AirGradient and Ruuvi do, takes it a step further again. Your data sits on your own hardware, and the monitor keeps working whatever happens to its maker. It's hardly the flashiest selling point, but it might be the one that matters most down the line.

That's it for Issue 03. If you found it useful, forwarding it to someone who'd appreciate it means a lot to a one-person publication like this. And if there's a device or topic you'd like me to cover next, just reply, I read every message. See you in a couple of weeks.

Ethan