I tested Blueair’s ‘smallest smart air purifier’ for two weeks in my home — it’s a quiet powerhouse for cleaner air

Blueair has already made a name for itself in the air purifier world, with many of its models topping the charts in our best air purifiers guide. And while we're big fans of the Blue Max 3250i at Ideal Home, awarding it a well-earned top position, it's now a little old.

So when the Swedish clean air brand launched the Blue Pure 511i Max – a new and updated version of our top-rated budget pick, the Blue Pure 511 – I was keen to put it to the test. After using it for the past two weeks, I think it's a solid all-rounder, and for an affordable price, too.

In a nutshell

The Blueair Blue Pure 511i Max is a stylish, lightweight air purifier that delivers great all-around performance for everyday use. It’s simple to set up, easy to use (thanks to the intuitive controls and app connectivity), and runs quietly enough on low settings that you’ll barely notice it’s there.

I've been testing this air purifier for two weeks now, and there's no denying that it does the job. It wasn't the quickest to register the dip in air quality during our smoke and cooking tests, but it made up for this when tackling VOCs in the deodorant test. Somewhat sadly, it didn’t register dust at all during testing, but this felt like a minor drawback in relation to the bigger picture.

Maintenance is easy, too. The pre-filter is machine washable, the main filter is simple to replace (with a handy reminder light), and at under 1p an hour to run, it’s energy-efficient enough for continuous use.

It's fair to say that I'm a fan of the Blueair Blue Pure 511i Max. If you’re looking for a quiet, effective purifier that doesn’t overcomplicate things, the 511i Max is a solid choice, and I'll certainly continue to use it in my home going forward.

Specifications

• Recommended room size: 22m²
• Air change per hour: 4.8
• CADR: 152 CFM (258 m³/h)
• Noise levels: 19-48dB
• Filter type: Pre-filter, particle filter, activated carbon, HEPASilent™
• Dimensions: 26.9D x 26.0W x 48H cm
• Weight: 1.29kg
• Wattage: 20W
• Smart app connectivity: Yes
• Timer: No
• Auto mode: Yes

How I tested

Katie Sims

I'm Katie, one of Ideal Home's regular digital contributors. Over the past three years, I've tested a variety of home appliances, including dehumidifiers, air purifiers, coffee machines, carpet cleaners, and vacuums.

I reviewed the Blueair Blue Pure Max 511i for two weeks in my home in Leeds. As part of how we test air purifiers at Ideal Home, I performed a series of controlled tests to measure how quickly the device could register a dip in air quality and return it to an acceptable level.

Unboxing and setting up

The Blueair Blue Pure 511i Max Air Purifier arrived in a lightweight box that was easy enough to carry solo from room to room. The box itself had a clean, minimalist design which neatly reflects the brand’s overall look and messaging.

Inside, the purifier was wrapped in sheets of single-use plastic, as was the user manual – something I found disappointing given Blueair’s focus on clean living. I’d have preferred to see more eco-conscious packaging materials used throughout.

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Setting the device up was simple enough. I plugged it in, pressed the power button on the control panel, and the purifier switched on without issue. To make the most of its features, I downloaded the Blueair app by searching for it directly in my app store. While the user manual includes a QR code, this (strangely) didn’t work for me.

Once I had the app, it took just a few minutes to connect the device, create an account and pair it with my WiFi. From there, the purifier was ready to use.

Design

Having tested the Blueair Blue Pure Mini Max already, I knew what to expect when it came to the design of the 511i Max. The biggest difference between the two models is (literally) the size – the 511i Max stands at 48cm tall, compared to the much smaller 29cm height of the Mini. While this newer model is certainly larger, it still feels compact enough to fit comfortably into most living spaces without dominating the room.

Like the other models in the Blue Pure range, this air purifier comes with a removable fabric knit cover, which is available in two colourways. The standard option is Stockholm Fog, a simple, neutral grey that won’t clash with most home decor styles. If you prefer something with warmer tones, there’s also the Limestone Beige option, which can be bought separately for £15.

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The user interface is clean and minimal, with clearly labelled buttons for power and fan speed, plus indicator lights for the device’s different modes. These include Auto, Night, and fan speeds 1, 2, and 3. There’s also a small WiFi icon that lights up when the device is connected, along with a filter replacement indicator.

On the front of the purifier is an LED air quality status light, which changes colour in line with the room's air quality: blue for excellent, green for very good, yellow for moderate, orange for polluted, and red for very polluted.

Overall, I quite like how the Blue Pure 511i Max looks in my home. There's something simple and minimalist about it which – aside from aligning with my personal decor style – feels very appropriate for an air quality device.

Performance

When we test air purifiers at Ideal Home, we prefer to judge them based on how they function in real-life home settings. To do this, we perform a series of tests that really put these devices through their paces, allowing us to paint an accurate picture of how they perform.

The Blueair Blue Pure 511i Max certainly looks the part and boasts some impressive-sounding features, but I was keen to see how well it lived up to its expectations. To gather a more detailed overview of how the device performed, I referred to the Blueair app consistently during testing. This offers a breakdown of current PM2.5 levels, which includes fine particles like dust, bacteria, and pet dander – the ones small enough to make their way into the bloodstream.

First up was the smoke test. I lit a match a safe distance from the air purifier, let it burn for a few seconds, then blew it out. I expected the air purifier to pick up on the change in air quality relatively quickly, especially given how close the match was to the appliance. However, it took 2 minutes and 45 seconds for the LED indicator to change from blue (excellent) to green (very good). Another minute later, it shifted through yellow (moderate) and landed on orange (polluted).

I kept an eye on the app throughout, and after around 7 and a half minutes, the LED indicator had returned to yellow (moderate). Eventually, it worked its way back through green and into blue, taking 13 minutes and 7 seconds in total to declare the air quality excellent again. The purifier did the job, but it wasn’t the quickest on this occasion.

Next, I moved on to the aerosol deodorant test, which ended up being the area where the Blue Pure 511i Max most impressed me. After spraying a generous amount of deodorant directly in front of the appliance, I saw that it responded much faster than during the smoke test. Within less than a minute, the LED changed from blue to green and quickly progressed through yellow, orange, and red (very polluted). On the PM2.5 scale, it peaked at 370.

However, while it was quick to detect the problem, it was slower to resolve it. It took 20 minutes for the indicator to drop from red to orange, and longer still to make its way through to excellent again. That said, the air quality did drop significantly lower than during the smoke test, so the additional 7 minutes does make sense.

After the Blue Pure 511i Max had worked its magic, I couldn't smell any deodorant in the living room. While I don’t tend to use aerosol deodorants myself (this was my partner’s bottle), I do use dry shampoo regularly, which also releases VOCs. Knowing the purifier is sensitive enough to pick these up is reassuring.

Then, I moved on to the test I was most looking forward to – the bacon test. As this is usually the test that sends air purifiers into overdrive – cooking fumes do produce a strong aroma after all – I placed the pan right next to the air purifier to give it the best chance of picking up the fumes quickly. As with the smoke test, I was a little disappointed when nothing happened at first. For the first five minutes, the LED light stayed blue (indicating excellent air quality), and the app showed a PM2.5 reading of 0, despite the bacon sizzling away and producing tell-tale fumes.

Once the air quality started to register a change, though, things moved quickly. By six minutes, it had shifted to very good, and by 6 minutes 15 seconds, it was already at polluted. At 9 minutes, it had reached the very polluted level, indicated by the stark red light. The air quality peaked at 58 on the PM2.5 scale.

The path back to clean air during the bacon test wasn’t linear. The indicator bounced between orange, green, and red a few times before starting to settle. I turned off the heat at 13 minutes, and by 15 minutes 30 seconds, the air quality had recovered to very good. At the 18-minute mark, it had returned to excellent.

The final test I did with the Blue Pure 511i Max (and possibly the most glamorous) was the dust test. Emptying the vacuum is an easy way to release dust particles into the air, so it's always a bonus when an air purifier can detect these and adjust its fan setting accordingly.

I emptied the contents of my vacuum cleaner onto the floor next to the air purifier and waited for the LED indicator to register a drop in air quality. Despite keeping my eye on things for half an hour, the indicator remained stubbornly blue throughout. The app also showed no change on the PM2.5 scale, holding steady at 0. This was a little disappointing, especially compared to how quickly the air purifier responded to the deodorant.

That being said, I do use the Hoover HFX Cordless Vacuum to clean my home, which has a built-in HEPA filter. HEPA filters are designed to capture micro-particles of dust, so the contents that were released onto my kitchen floor might not have contained enough micro-particles for the air purifier to pick up on.

Ease of use

When it comes to usability, the Blueair Blue Pure 511i Max Air Purifier keeps things refreshingly simple. With just two buttons on the control panel – one for power, and one to cycle through modes – it's really easy to get the hang of, even if you’ve never used an air purifier before.

The buttons themselves are touch-sensitive and responded instantly every time I used them – an improvement on the last Blueair model I tested, where I often had to tap them more than once for them to activate.

Tapping the fan button cycles through the different modes: Auto Mode, which lets the purifier adjust its fan speed based on the air quality; Night Mode, which runs at the lowest fan speed and dims the lights for uninterrupted sleep; and manual fan speeds 1, 2, and 3. It’s all clearly displayed via the LED lights on the control panel, and the feedback is immediate.

If you don’t fancy getting up from the sofa, the Blueair app mirrors all of these settings – so you can adjust the fan speed, switch modes, or check air quality from your phone. I found this particularly useful after cooking, when I (sometimes) wanted to ramp things up quickly without leaving the comfort of the couch.

Overall, I'd say it strikes a good balance between keeping things user-friendly while still giving you enough control to tailor its performance to your needs.

Noise levels

One of the standout features of the Blueair Blue Pure 511i Max Air Purifier is how quiet it is – especially on the lowest fan setting. According to the product specifications, it runs as quietly as 19dB, and I was able to verify this using an independent app. Most of the time, I left it on Auto Mode, and because my home’s air quality (thankfully) shows as excellent most of the time, it rarely needed to crank the fan speed up. As a result, I often couldn’t even hear it running unless I was right next to it.

On higher fan settings, it does get noticeably louder – particularly on level 3 – but even then, it tops out at 48dB. That’s still considerably quieter than some other models on the market, like the Shark NeverChange5, which reaches up to 66dB at full power.

During testing, the air purifier never needed to stay on its highest setting for more than 30 minutes at a time, so the extra noise was easy enough to tolerate, knowing it was working hard to clear the air. Overall, if you're sensitive to sound – especially at night – this is one of the quieter air purifiers available.

Portability

When it comes to portability, the Blueair Blue Pure 511i Max isn’t the most travel-friendly option in the Blueair range – especially when compared to the Mini Max, which was designed with portability in mind. And especially as Blueair is marketing this model as their 'smallest smart air purifier.'

With a height of 48cm, it's a little on the taller side, but it's by no means heavy or awkward to carry around. It weighs just 1.29kg, which is impressive considering its size. There’s no dedicated carry handle, but it’s easy enough to pick up and move using both hands.

Personally, I'll be keeping my Mini Max to hand for when I want to quickly move it to a different room, and using the 511i Max as our 'main' air purifier, given it packs a more powerful punch and boasts smart connectivity features. But, the bigger model is still fine to relocate if you need to.

My only concern is that, with the device being on the larger side, I’ve had to be a bit more intentional about where I place it so it doesn’t end up feeling like it’s in the way. Thankfully, the minimalist design and neutral fabric cover mean it doesn’t stand out or clash with the rest of the room – so even when it’s not tucked into a corner, it never feels like an eyesore.

Energy use

The Blueair Blue Pure 511i Max is impressively efficient when it comes to energy use, drawing just 20W at full power. Based on the current Ofgem energy price cap, that means it costs less than 1p an hour to run – which is great news if the cost of running an air purifier is a concern for you.

There’s no dedicated Eco Mode, but given how little power it uses, it’s unlikely to make a noticeable dent in your energy bill. It’s a good option if you’re looking for a purifier that can quietly and consistently improve your air quality without driving up your running costs.

Filter replacement

Replacing the filter on the Blueair Blue Pure 511i Max is straightforward, with no guesswork involved, thanks to the indicator light on the control panel. When it’s time for a change, the light turns red to let you know

To access the filter, the top of the device twists off easily. From there, the fabric pre-filter and noise filter are removed, then the main filter lifts out using two built-in handles. Swapping in a new one takes just a few seconds. Once everything’s reassembled, I held the fan button down for 15 seconds to reset the filter indicator – all of which was outlined in the user manual.

You can buy a replacement filter for £24.53 on Amazon. It's not the cheapest, but it’s a worthwhile investment if you want to keep the purifier running efficiently.

As for the rest of the air purifier maintenance, the fabric pre-filter can be vacuumed with a soft brush attachment to keep it free from dust. It’s also machine washable, though you’ll need to let it dry for 12 hours before putting it back on the device. All in all, I'd say the Blue Pure 511i Max is a low-maintenance model with a filter system that’s easy to manage.

How does it rate online?

At the time of writing, the Blueair Blue Pure 511i Max Air Purifier has a strong 4.7 out of 5-star rating from 171 reviews on the Blueair website.

Customers have been particularly impressed by its ability to eliminate odours, with several noting that it effectively removes the smell of smoke, cooking, and even cat litter. Many also praised the sleek, minimalist design and how lightweight the unit is.

The Smart connectivity features have also gone down well with users, with reviewers appreciating how easy it is to monitor and control the device via the Blueair app. Overall, most users seem to agree it’s a solid performer that’s both practical and stylish.

Should you buy the Blue Blue Pure Max 511i?

If you’re after a stylish, low-maintenance air purifier that performs well in everyday home environments, the Blueair Blue Pure 511i Max is a solid choice. It’s easy to use straight out of the box, and the lightweight, compact design means it doesn’t feel intrusive – either visually or physically – even if space is tight.

Performance-wise, it's a strong all-rounder, responding particularly well to VOCs in our deodorant test. While its reaction to smoke and cooking fumes were slower than expected, the purifier did eventually restore air quality without needing constant input. It also failed to register a dip in air quality during our dust test, which was a shame. This might be because my vacuum's built-in HEPA filter had already done all the hard work, though.

But I think the positives definitely outweigh these drawbacks. The device's near-silent operation on lower settings and low running costs make it a great option for continuous use, and maintenance is refreshingly simple.

At 48cm tall, it’s a little bulkier than some portable alternatives – but if you’ve got a suitable spot for it, the neutral design means it won’t look out of place. Overall, it’s a solid pick for anyone looking to improve their home’s air quality with minimal fuss.