Air Purifier

I will review one of the most popular air purifiers of the last few years: the Blue Pure 211+ from Blueair.

Since we started housefresh.com, we have tested and reviewed a few Blueair air purifiers.

Looking at Google Trends to gauge popularity, we can see that the 211+ first arrived in 2016 and reached its peak popularity in 2021 – too late for a review?

I don’t think so…

Although Blueair has now replaced the 211+ with the new Blue Pure Max 211i, many people are still looking to buy a 211+ as it’s still widely available, and many others own a 211+ and are wondering if it’s time to upgrade it, so this review is for them.

As always, we bought the Blue Pure 211+ with our own money. I paid £110 for our 211+ in early 2022, but you can find the 211+ on Amazon today for $319.99 — or you can get the latest Pure Max 211i in the U.S. for $349.99.

In this review, I will compare the Blue Pure 211+ to the more than 100 air purifiers we have tested at HouseFresh, based on our first-hand data on air cleaning performance, sound generation, energy efficiency, real-life user experience and long-term running costs. If you want to know more about how we test our air purifiers, please read this article or watch this video.

The lowdown on the Blue Pure 211+

Looking for the quick-fire facts? Here are my main pros and cons of the Blueair Blue Pure 211+.

Blueair’s signature Scandi design with one-button operation

A bulkier Blueair device with a removable pre-filter fabric you can replace and customize, similar to other models in their range.

Before jumping into the performance data, let’s look at the design of the 211+.

Blueair’s Blue Pure range has a distinctive aesthetic. The fan sits at the top of the device and the filter is tucked in underneath, covered by a colorful pre-filter fabric.

The 211+ is the largest unit in the Blue Pure range, and it takes up much space. 

It takes up as much floor space as the Levoit Core 600S but it doesn’t come with any handles, so you need to carry it around in your arms to move it.

It is much bulkier than the AirFanta 3Pro, which has a higher CADR (430) and costs half the price. 

The filter sits underneath the top half of the 211+ and is covered by a fabric pre-filter that comes in 5 color options to match your decor. 

The controls for the Blue Pure 211+ couldn’t be simpler. There is one large circle button at the front that you can tap to move across three fan speeds and the on/off switch.

This makes the 211+ super easy to use right out of the box, but you don’t get any extra features like child lock, timers, disabling the ionizer, or any of the other buttons we see on other air purifiers as standard. As an older model, it also doesn’t have any app support.

  

One annoying aspect of the 211+’s design is that when you pick it up to move it, the bottom half may or may not detach from the fan and fall to the ground. This doesn’t happen every time but it definitely has gotten worse over the years for my device, after each time I replace the filter.

Which brings me to the filter.

A particle filter with a layer of carbon that is supercharged with bipolar ionization

The 211+ uses Blueair’s trademarked HEPASilent filters to remove microscopic particles without noise.

The filter in the 211+ consists of four layers of filtration:

First, you get the pre-filter which is made out of fabric and comes in different colors. 

As with any pre-filter, you will need to keep it clean by vacuuming it regularly. Blueair has made it easy to remove it for cases when it needs a deeper clean, so you can wash it in a washing machine using cold water.

Then, you get an ultra-thin polypropylene filter, which is the main particle filter. 

As shown by the new generation of PC fan kits that use MERV 13 filters, lower-grade particle filters are not a bad thing for air purifiers, as air will pass multiple times through the filters and the higher airflow helps to improve the speed of cleaning.

Going deeper, you get a carbon filter for odors and gases.

Unfortunately, this is just a layer of carbon-impregnated fabric, so it will be less effective for VOCs and bad odors compared to the pelleted activated carbon we see in other models of air purifiers. 

Lastly, you get Blueair’s trademarked HEPASilent technology.

According to Blueair, its HEPASilent technology “electrically charges particles that are drawn into the device, causing them to adhere to the particle filter, where viruses and bacteria are inactivated.” The marketing materials also state that “HEPASilent filtration can deliver up to 45% more clean air faster than HEPA H13.”

What Blueair is describing sounds a lot like ionization.

Air ionizers emit electrostatic discharges into the air that alter the particles’ structure, making them heavier and forcing them to drop onto surfaces or within the device itself so they can be cleaned.

However, Blueair’s marketing materials do not mention ionization. Instead, they mention “electrostatic filtration.” 

This makes sense as ionizers don’t have a great reputation because they can produce potentially dangerous by-products, including ozone, aldehydes, and fine particles, which can negatively affect the health of those with respiratory conditions.

It is worth mentioning here that Blueair air purifiers sold in the U.S. are CARB-certified, which means that their ozone emissions have been tested and proven not to surpass 50 parts per billion (ppb). They are also certified by Intertek as ozone-free…

After digging deep into their website, I found a page where they clearly explain the difference between ionizers and HEPASilent technology:

Blueair states that HEPASilent technology can’t be associated with ionizers because their devices combine electrostatic filtration with mechanical filtration. 

It’s important to note that the ionizer feature cannot be turned off on this device. Many people wrongly assume it will generate ozone, but a third-party lab test by Intertek provides a certificate for zero ozone (≤ 0.005 ppm).

In terms of the filter itself, it is straightforward to install; simply twist the body of the purifier and slot it inside with the carbon filter facing upwards.  Here’s a video on how to do it.

The Blue Pure 211+ cleared our test room in 20 minutes

This is faster than some of our most recommended air purifiers, such as the Levoit Vital 200S and the Winix 5500-2.

We first tested the Blueair 211+ back in 2022 using our PurpleAir Indoor sensor, so before I started working on this video review, I re-tested the 211+ using our new PurpleAir Zen sensor:

According to our Zen sensor, the 211+ needed 20 minutes to achieve PM1 zero in our 728 cubic ft. test room:

We can compare this to other similarly-priced devices running at their top speed:

Considering this air purifier was released in 2016, the results at top speed are impressive. 

As I mentioned above, the Blueair Blue Pure 211+ comes with electrostatic filtration through their HEPASilent technology but (unlike manufacturers such as Winix, Alen and Coway) Blueair doesn’t allow you to turn off the HEPASilent in the 211+.

Smart Air has long stated that “adding an ionizer is an extremely cheap way for an air purifier company to increase its purifier’s CADR,” so I was intrigued to see how much of an effect Blueair’s HEPASilent has on the 211+’s performance.

After much deliberation, I made the drastic decision to remove the ionizer:

With HEPASilent enabled, the Blue Pure 211+ completed our air cleaning test in 20 minutes. Without HEPASilent, the same test took a whooping 38 minutes.

Before running the test, I assumed that HEPASilent would boost air cleaning performance a little, helping the 211+ complete our particle removal test just a few minutes faster than without HEPASilent as this is what we usually see with other air purifiers when we disable their ionizers.

However, as the table above shows, removing the ionizer in the 211+ had a much bigger impact on air cleaning performance compared to other air purifiers.

In fact, our test shows that removing the ionizer in this Blueair device led to a 62% drop in performance.

So if you were considering removing the ionizer inside your Blue Pure 211+, keep in mind that you will significantly reduce its air cleaning performance.

I believe this explains why Blueair doesn’t include an option to disable HEPASilent in the same way other manufacturers do.

Incredibly quiet considering its size

In our testing, the sound levels of the 211+ ranged from 37.2 dBA to 55.7 dBA

If an air purifier is too loud, you will find yourself turning it off eventually.

That is why we always measure how much sound they generate from 3 ft. away. 

These are the results for the 211+:

Be aware our background noise is 35 dBA, so the 211+ running at speed 1 is likely to generate less sound if you could measure it in a silent room.

But feel free to have a listen for yourself:

As these figures won’t tell you much in isolation, I made a comparison with other devices that have similar performance:

The 211+ is quieter than most when compared to other similarly powered HEPA retail devices. However, it is out-matched when we compare it to PC fan-powered devices like the Luggable XL-7 from CleanAirKits. 

One of the benefits of a high-CADR air purifier is that you can use it on a lower fan speed and still achieve a good level of air cleaning performance.

So we retested the particle removal performance of the 211+ when running at its lowest fan speeds.

Running at speed 2 it generates 45.8 dBA, which is just above the 45 dBA limit that CleanAirStars recommends for noisy classrooms or offices. it managed to reach PM1 zero in 28 minute

When running at speed 1, it generates 37.2 dBA, which is below the 40 dBA recommended for quiet classrooms and offices. At speed 1, the 211+ reached PM1 zero in 45 minutes.

We can compare these results with other air purifiers running at sub-45dBA:

Running at lower fan speeds, the Blue Pure 211+ performs well when benchmarked against other similarly powered devices we have tested at low speeds. This is likely to be thanks to its HEPASilent technology.

However, concerning performance at low sound levels, the 211+ is still no match to PC fan-powered air purifiers like the AirFanta 3Pro or the CleanAirKits Luggable XL-7.

Let’s look at how much the 211+ will cost you in the long term, starting with your energy bill.

The cost to run a Blueair Blue Pure 211+: $197.27 per year

1. Electricity costs = $57.29 per year

As always, we used our energy meter to record the 211+’s energy use when running at each fan speed and also while on standby.

I also measured how much power was used once I removed the ionizer.

If you had to leave your Blueair 211+ running 24/7, it would cost $57.29 per year in energy costs.

With this calculation in mind, we can compare the annual energy costs you can expect from the Blueair 211+ to other devices we have tested:

Energy usage compared to performance is very fair with the Blue Pure 211+, which must be due to the combination of a lower-grade particle filter and electrostatic filtration.  

2. Filter costs = $139.98 per year

It’s not just energy costs that add to the running cost of an air purifier and you will also need to replace the filters eventually. 

Blueair says you need to replace the filters for the Blue Pure 211+ every 6 months. The recommended OEM filters cost $69.99 for the standard filters, but they do offer options with extras that go up to $89.99.

This means the total filter costs for one year for the Blue Pure 211+ is $139.98; We can combine that with energy costs and compare with other similar performing air purifiers:

The Blue Pure 211+ is this group’s second most expensive air purifier, costing over three times more than the Luggable XL-7 and nearly twice as much as the Vital 200S. 

This is likely due to the lower filter life, as the filter needs replacing every 6 months, compared to 12 months for the Levoit Vital 200S.

Bottom line: Is the Blueair Blue Pure 211+ worth it?

Its combination of a lower-grade filter and ionization function provides good air cleaning power at lower fan speeds.

When I first reviewed the Blue Pure 211+ in 2022, I was blown away by its performance because it was a relatively cheap air purifier, yet it could effectively clean the air. 

As our new data shows, even when running at speed 2, the 211+ has an estimated CADR of around 230 cfm, and at speed 1 you will get the same performance as the Levoit Core 300 running at top speed (140 cfm). 

So why did Blueair air purifiers never make it to my list of the best air purifiers?

Well, the Blueair Blue Pure range uses an ionizer process to help clean the air, which is also found in devices from Coway, Winix and Alen. 

However and unlike Coway, Winix and Alen, with the Blueair 211+, the user has no way of switching off this function. 

To be clear, I don’t believe that the Blue Pure 211+ creates large amounts of ozone. I was unable to detect any with my ozone detector after leaving it running and it also has a certificate from Intertek to state it creates less than 0.005pm of ozone.

If you do have one, the performance is good as long as you have no issue with the ionizer, and know it can be very effective even when running on lower quiet fan speeds.  

Founded in Sweden by Bengt Rittri, Blueair has been around for over 20 years. Rittri wanted his children to breathe the same clean Stockholm Archipelago air while they spent time in the city. Thus, faithful to this vision, he started the company, creating simple and efficient air purifiers inspired by nature.

Back in 2016, Blueair became a Unilever brand. According to Rittri, the global company would help expand Bluair’s capability to reach more people in need of simple and affordable solutions for air pollution. The brand obtained a B Corp certification in 2023 with a clear mission of improving air quality in homes, schools and offices worldwide, focusing on children’s right to clean air.

I love the social and environmental commitment of the brand, as well as Rittri’s belief that freedom to breathe is a basic right. But we’re not here for the charms and chimes of brand positioning and marketing. 

When it comes to cleaning power, Blueair mixes simplicity with efficiency and offers an array of models for different space sizes. All units, however, feature the trademark HEPASilent™ Technology that combines electrostatic and mechanical filtration. I’m not a big fan of ionization, but we’ll get into that later.

As for the Blue Pure 411, it’s better suited for small rooms. It’s worth noting, though, that since Blueair became part of the Unilever family, its product range has broadly expanded. The launching of the Pure Max line in 2023 replaced some of the older models, including the Blue Pure 411. 

With such a prolific portfolio, navigating models can be a bit confusing, especially regarding filter replacements. Blue Pure 411, 411 Auto, and 411+ are three separate models but share the same filter; the 411a Max, on the other hand, use different ones. In a core comparison, however, they are not that far apart: the CADR rating, filter mechanism and Blueair’s HEPASilent™ Technology are scarcely different when not the same. As of 2025, Blueair has released a smaller Blue Pure 511i Max ‘s that is cheaper and has a lower CADR.

But if you’re here, you probably want to know more about the Pure 411 and its performance. So, let’s get to it.

The lowdown on the Blueair Pure 411

Innovative concept but has no outstanding cleaning power.

We’ll delve into a detailed analysis of the Blue Pure 411, covering design, performance and noise output, among other things. But if you want to know black over white, our take on the pros and cons of the unit, check out the chart below:

The specs

The range of small air purifiers was much more limited when the Blueair Blue Puro 411 was launched. It wasn’t the most budget-friendly air purifier back then, but its CADR was ok (120 CFM) compared to other popular small units, such as the Levoit Core 200S (118 CFM). 

However, the standout point of the Puro 411 was the original design that disrupted the scene with lively colors and scandic aesthetics.
Since the newer Max Pro line became the key product Bluair focuses its communication on, the Puro 411 can now be found at $119 on Amazon — although still more expensive than the reliable Levoit Core 300 or newer and highly efficient units like the Winix A230.

Minimalistic build, playful design

A thoughtfully engineered structure with customizable looks, although somewhat on the flimsy side.

Blueair was created with children in mind. It only makes sense that the original Blue Pure line is so colorful and lively yet has straightforward controls. I opted for the Diva Blue fabric pre-filter (which brings this iconic Diva to mind), but there are six colors to choose from, ranging from buff yellow to a sober dark gray for those who prefer a more subtle approach.

The top white cylinder houses the fan and ionizer, crowned by an organic-shaped control panel. The lower body accommodates the pre-filter and main filter, which fit neatly into a plastic honeycomb structure. The rounded body allows for an efficient 360 air inlet, while the clean air is then released from the top grill.

Designed for ergonomic efficiency with the minimum amount of elements, the Pure 411 is both compact and lightweight (5.3 lbs). As the smallest unit of the Blue Pure line, it will easily fit even in tiny rooms, not using up too much space, while it weighs close to nothing to move around. 

However, this also means the structure requires gentle handling as there’s no outer casing or grill to protect the filer when manipulating the unit. Besides, most of the weight is at the top cylinder, so it’s somewhat flimsy and easier to tip over. 

Simplicity peaks with the control panel. There’s only one button on the Blue Pure 411 to switch on and off and cycle through three fan speeds. That’s right, even the young members of the family could operate it. 

Press the big round button once to start the air purifier at the lowest speed; a second and third press will step up the unit to the following fan speeds. One last touch will switch it off. The white LED lights around the button indicating the speed it’s on will dim after seven seconds of no interaction. 

This is one of those nice touches that show how thoughtful Blueair designers are, especially if you’ll be placing the unit in the bedroom. For that matter, however, it would be nice to have a no-lights function.

Although the one-button control is modest and straightforward, the Pure 411 has a built-in memory, so if you unplug the unit, the unit will remember your settings once replugged. Yet, this is the only “smart” feature, as there’s no auto mode, timer or app support. 

Blueair’s trademark HEPASilent™ filtration system

What’s this technology all Blueair purifiers feature? 

In short, HEPASilent™ technology is no more than a HEPA-type filter boosted by an ionizer. It’s a bit misleading, as the filter is not a real HEPA. But many brands coin creative names for their products using keywords we look out for to feel secure about our purchases. With this trademark, brand communications can use the word without the certification required for it to be real HEPA.

Blueair filters are less dense than HEPA. This is not all bad, as a thinner filter media requires less power to create an airflow capable of passing through it. That’s how their units can clean the air with low energy consumption and more silently —hence the HEPASilent™.

But to remove 99.97% of airborne pollutants, this type of filter is not enough. That’s why Blueair combines mechanical (HEPA-type) with electrostatic filtration. An ionizer within the fan’s hood produces an electrostatic discharge, releasing ions that attach to airborne pollutants making them stickier and heavier, thus easier for the unit to capture and filter.

The downside of this technology is that it produces ozone as a byproduct. According to Blueair’s website:

All Blueair air purifiers are CARB certified which means that they are considered safe and do not exceed ozone emission limits.

Not exceeding ozone emission limits isn’t the same as not producing ozone at all. And then, even a slight amount of ozone can react with common gasses found in every home (including fumes from cleaning products) and produce further VOCs such as formaldehyde.  

However this type of combination device is unlikely to introduce any ozone as the particle and carbon filters will help to remove the ozone from the ionizer before it leaves the device. The larger 211 of the Blue Pure series has a certificate showing that it produces zero ozone emissions —check the certificate at Intertek— so we can assume the same with this smaller device in the series.

Sadly, the ionizer cannot be switched off on Blueair purifiers. Both technologies are engineered to work together, unlike other units that have an ionizer as a plus (such as the Winix Plasmawave).

The filters also feature an activated carbon layer, although it’s an impregnated fabric instead of granular or pelleted charcoal.

This media is not robust enough to deal with serious odor or VOC issues, but it will help with mild everyday smells.  

Lastly, there’s the outer pre-filter that traps bigger particles such as lint, dust and pet fur before they reach the mail filter. Washable prefilters are a functional upgrade as they can be thrown into the washing machine or vacuumed easily. Blueair recommends cleaning the pre-filter every three months to extend the lifespan of the main filter.

Now, the steps to change the Blue Pure 411 filter are somewhat different compared to other more traditional air purifiers. But the process is still pretty straightforward. 

After six months of continuous use, the LED lights on the one-button control will turn red, indicating it’s time for a filter replacement. After unplugging the unit, unscrew the top cap with a gentle twist. Remove the fabric pre-filter and pull out the main filter using the tabs on the sides. Place the new filter on the plastic structure, then the pre-filter and finally, replace the cap.

The Blueair Blue Pure 411 cleared our test room in 68 minutes

Silent and easy to look at, but far from being the fastest.

We often find that brands claim (and big publishing companies spread all over the internet) far more than their products actually deliver. That’s why, at HouseFresh, we like to take things into our own hands. 

We conduct our performance tests in our 728 cubic ft. home laboratory. What does the HouseFresh testing process involve? We first generate pollutants by burning incense sticks. The PurpleAir Touch Indoor Air Quality Monitor —one of the most accurate sensors in the market— then helps us track how fast (or slow) each unit removes the PM1, PM2.5 and PM10 produced by the incense smoke.

As all of our tests are conducted in the same space, we can easily compare results across units. 

Now, without further ado, let’s get a look at the data:

Air cleaning performance, compared

Cleaning speed is a good indicator to asses an air purifier’s performance. Knowing the Blue Pure 411 took 68 minutes already gives us an idea of its efficiency. But it’s usually not as graphic as comparing it with other units. 

Let’s start by saying the Blue Pure 411 is an air purifier designed for small rooms. According to the Energy Star testing, it can achieve five air changes per hour in spaces of 163 sq. ft, with a CADR rating of 120 CFM. 

It’s only fair, then, to compare its performance with other small air purifiers. The most straightforward comparison is with its upgraded version, the Blue Pure 411+ (which is not the 411 Auto nor the 411 Max models). The 411+ is not only 25 minutes faster, but it also comes with smart features and app support. 

The Levoit Core 200S is another similar unit that, with a lower CADR (118 CFM) and for less money, cleaned our lab seven minutes faster than the Blue Pure 411. Besides, Levoit units only use mechanical filtration.

It’s not all bad news, though. There are slower air purifiers on the market, such as the Aroeve MK01 or the $700 Dyson PH03. In truth, neither of these are air purifiers we recommend. But, then, speed is not the only determining factor in choosing an air purifier. Other aspects of the Blue Pure 411 make it a suitable option for small rooms— take the noise output, for example.

Noise levels test results, compared

Using a commercial sound meter, we registered the decibels (dB) emitted by the Blue Pure 411 at every fan speed from three ft. away. 

The HEPASilent ™ technology is indeed quiet, at least to a certain extent: at its lowest fan speed, the noise output was 36.2 dB — which is equivalent to a soft whisper. Plus it gets quieter in Sleep Mode. In fact, you need to be really close to the unit to hear its hum in this setting. 

But then, at top speed, there’s a noticeable change. The dB rises to 53.1 dB at its fastest. For reference, 50 dB sounds like a quiet office.

With these results, I can only say the Blue Pure 411 delivers the Silent promise to a limited extent. Yes, at 36.2 dB is fairly quiet. But then, we should factor in the fan’s power at each speed.

As you can see, the airflow changes drastically among speeds. It can be quiet at the lowest, alright, but the cleaning power is significantly reduced. With that fan power, the small Blue Pure 411 would make little changes to your air. 

Besides, the AHAM CADR testing is always done at an air purifier’s highest speed, meaning that the unit should be running at top speed to achieve the 120 CFM and five air changes per hour in a small room.

But decibels are a rather abstract measurement. And perception of sound varies from person to person. That’s why we’ve recorded the unit’s noise output. Hear the Blue Pure 411 in action for yourself.

The cost to run a Blueair Blue Pure 411: $57.03 per year

An outstandingly energy-efficient unit with affordable replacement filters.

1. Electricity costs = $15.25 per year

The initial purchase price is only one variable to determine if an air purifier is a good investment. Then there’s the fixed costs you’ll be facing in the long run, including energy consumption and filter replacements.

In terms of electricity costs, Blueair’s HEPASilent™ technology is remarkably efficient. The Blue Pure 411 is no exception: it made the 2024 Energy Star Most Efficient list, which features the year’s most energy-conscious appliances. For a somewhat old model, this is saying a lot.

The 411’s power consumption ranges from 0.1 W to 10 W at the lowest and fastest speeds, respectively. This means that if you were to use the unit all year round, 24/7, at top speed, the cost would be $1.3 a month. To put it into perspective, an average LED light bulb uses about 10 watts. Not bad at all.

2. Filter costs = $41.78 per year

In addition to energy usage, it’s important to factor in the filter costs. Eventually, all HEPA (and HEPA-type) filters need replacement. The airborne pollutants trapped by the air purifier accumulate on the filter’s surface — which, in the long run, becomes clogged with those same filtered particles. 

Now, the frequency of filter replacement depends on how much you use the unit and the level of air pollution in your area. But as a general rule, Blueair recommends changing the Pure 411 filters every six months. This brings us to two filters per year, summing up to $41.78 if you buy the original ones.

When compared to similar units, Blueair’s filters are reasonably priced. The Levoit Core 200S and 300S filters, for example, cost between $25 and $30, slightly varying on the unit. Then, the Winix A230 replacement filters can be found at $49.99, although you need to replace these only once a year.

Besides, as the Blue Pure 411 has been around for quite a long time, there are plenty of generic, cheaper options available. Although we’ve only tested the unit with genuine Blueair filters, so we cannot vouch for their performance.

Bottom line

There’s a playfulness about the Blue Pure 411 that makes it unique.

The simple one-button control adds the perfect touch to that lively flair I miss in the new Blueair Max line. The brand has taken a more sober turn on the latest designs, aligning with current trends that demand desaturated colors and textures. But I kind of miss the old cheerfulness. 

In terms of performance and functionality, the Blue Pure 411 is compact, has low running costs and operates reasonably well. All these features make it a good choice for small rooms like bedrooms. 

However, if you prefer pure mechanical filtration, then the Levoit Core 300 (or 300S if you would like to upgrade to a smart unit) is one reliable unit I know I can trust. Then, if you are looking for an air purifier for bigger rooms, I’d take a look at the Levoit Vital 200S, which can achieve five air changes per hour in 375 sq. ft. in 21 minutes.

We calculated yearly costs associated with running the Blueair Blue Pure 411 24 hours a day, 365 days per year utilizing the latest average energy prices as reported by the Bureau of Labor Statistics of $0.174/kWh as of April 2024.