Hi Everyone!

It’s been a while since the last newsletter but this time I actually have a good reason. My wife and I recently welcomed our newest family member, Aurelia, who was born late last week. Needless to say, many things got a bit delayed.

One thing our newest family addition has emphasised to me is how important air quality is, especially as this week much of the Philippines has been blanketed in wildfire smoke from fires burning in Indonesia. It’s been a challenge to keep PM2.5 levels in the house down, but we’ve been managing with a bit of DIY and some air purifiers and air quality monitors.

That leads me into the topic of today’s newsletter - air purifiers. For a long time, I’ve focused almost entirely on air quality monitors and over the past six years, I’ve only published three air purifier reviews. Now, since the start of 2026, I’ve already published six additional articles. The reasons for this are obvious - purification is one of the next logical steps after monitoring (there are a few other reasons too, but let’s keep this simple!).

However, one thing always bothered me about air purifier reviews. While there are some fantastic independent websites out there (like HouseFresh!), the vast majority of review websites either don’t test purifiers properly or they have a scoring methodology that isn’t transparent (or worse, doesn’t even exist). So, with transparency in mind, I decided to create a whole page that discusses my methodology for each type of review - air quality monitor, air purifier, and mask/respirator - so anyone can find out exactly why I awarded the score that I did. If you’re interested, you can learn more here.

To go even further with the transparency, I’ve also decided to make my purifier test results downloadable. If you’re curious, you can simply click the ‘download CSV’ links at the bottom of any graph. While this took many hours to set up, I hope the results are worth it and help guide people to making the best purchasing decision for their situation.

While I am still just getting into the air purifier review space, there are a few devices that I’ve tested already and some have impressed me. Others… Not so much. Let’s start with the devices we run in most rooms of our house.

Xiaomi air purifiers are quite interesting because across their range (4 Compact to the Elite) they tend to be good performers with fairly reasonable ongoing costs and great connectivity. However, depending on where in the world you live, they go from being practically a ‘no-brainer’ to being a tough sell. For example, I purchased the 4 Compact (the most affordable device in the range) for the equivalent of $66 USD here in the Philippines. There’s not a single device that competes with it. However, in the US, the device goes for $99-$120, and there are other similarly priced options like the Levoit Core 300 that trade blows with it.

After looking into regional pricing, it seems that Xiaomi purifiers are almost unbeatable in much of South and South East Asia as well as some other markets. However, in most Western markets, they are both pricier and there are far more alternatives available.

Before I digress too much, I do think Xiaomi air purifiers are worth considering. In Western markets, they typically offer good performance for the price, though not best-in-class. Where they make up for this is in being well-rounded - they are generally relatively affordable to keep running, have good connectivity, and look nice. If you are in a market like mine, they offer an almost unbeatable price-to-performance ratio and that’s before you consider the other strengths of these devices. Interested in reading the full reviews? You can find them below:

Mijia 6 Smart Air Purifier Review (mid-range)

Xiaomi 4 Lite Air Purifier Review (budget option)

Xiaomi 4 Compact Air Purifier Review (compact, low-cost option)

I also published a video on the 4 Compact if you prefer that format:

After using Xiaomi air purifiers in our house for over six months, I finally got the chance to test perhaps the biggest competitor - Levoit. I reviewed both of their most popular units, the Core 300 and Vital 200S, and came away feeling mixed about the Core 300, but positive about the Vital 200S.

The 200S is the purifier that now lives in our master bedroom and it’s the main device tasked with ensuring we breathe clean air when we sleep. It earnt this spot because of its 387 m³/h CADR (measured by me, the official figure is 425 m³/h), relative silence at lower speeds, and convenient size and shape. In our room, there isn’t much space for a cylindrical filter purifier like the Xiaomi models to pull in air, so a device that can sit against a wall and pull in air through the front is perfect. Oh, I also love the Vesync app so that’s a big advantage!

The Core 300 was a more difficult sell for me. It’s a very capable little device, and it offers more CADR than the Xiaomi 4 Compact that it competes with. However, it does this at a higher power draw (significantly higher!) and without the smart features. As soon as you want those, you’re looking at the Core 300S which is usually $50 more expensive. If all you want is power in a small form factor, the Core 300 is a good pick. However, the 4 Compact drops the power a bit and adds a range of other smart features instead. On sale, the Core 300S is likely worth jumping up to.

If you’re interested, the full reviews are below:

Levoit Core 300 Review (compact, low-cost option)

Levoit Vital 200S-P Review (budget option)

Out of these devices, what do we actually use? Well, it’s a bit of a mix. At the moment, we are running the Mijia 6 in the combined living room & kitchen area, the 4 Compact stays in my office, the 4 Lite keeps our spare room clean, and the Levoit 200S is in charge of our master bedroom. Ideally, I would probably swap the Mijia 6 for something more powerful as it struggles to meet the ideal number of air changes per hour (ACH) for a room that large. However, anything more powerful than the Mijia 6 quickly becomes quite pricey so that’s my device of choice for now.

The issue with every purifier I’ve tested so far is that the automatic modes are, frankly, terrible. In some cases (the Levoit 200S, for example), the PM2.5 sensor is very bad. In other cases (the Mijia 6), the sensor is decent, but the thresholds that Xiaomi has set are far too lenient. As such, I’ve had to set up automations in Home Assistant that control the speeds based on readings from dedicated air quality monitors. Since all of the purifiers mentioned above can integrate with Home Assistant, I’ve used that to map and control our home air quality. You can see the results below.

If anyone is interested in how I set this up, please let me know! Perhaps that can be the topic of a future newsletter or blog post.

So far my experiences with air purifiers are still relatively limited. However, it’s been an interesting niche to expand into and I’ve found the testing process quite exciting. I’m looking forward to hopefully reviewing more devices in the future and there are a few devices in particular that I’m trying to get in for testing. I hope to have those reviews out soon!

If you’ve read this far, thank you and I hope you learnt something! If the newsletter was helpful, I would truly appreciate it if you could share it.

Until next time!

Ethan