The Blue Pure 311i Max is a mid-sized air purifier from Blueair, available worldwide under various model names, including the Blue Pure 3350i Max (Europe) and the Blue Pure 3450i Max (Oceania and parts of Asia).

The 311i Max has smart functionalities, such as WiFi connectivity, auto-mode, an LED air quality indicator and an app that allows you to control the air purifier remotely. As with other devices from Blueair, it features their trademarked HEPASilent technology which combines mechanical filtration with electrostatic ionization.

The overall score for the Blue Pure 311 Auto Blueair incorporates first-hand data results from our battery of tests, as well as our ratings for customer service, brand transparency and design & UX. Check out the full scorecard below to see the split of categories.

The pros and cons of the 311i Max

A summary of our top-level findings after testing this air purifier following our methodology.

Blueair 311i Max

“Raw figures from our particle removal tests show that this air purifier offers solid air cleaning performance, and the use of HEPASilent allows the 311i Max to clean a lot of air without consuming too much energy.

If you don’t mind the use of electrostatic ionization, then this could be a good option for you.

danny
Danny Ashton
HouseFresh Founder
& Lead Tester

What we really like

Good air cleaning performance at top speed for less than $300, comparable to what you’ll get with the Winix T810 and the Dyson BP06.
Low energy usage that helps keep long-term costs low – it is less power-hungry than smaller devices like the PuroAir 240 or the Molekule Air Mini+.
The app works well and allows you to operate the 311i remotely.
It is aesthetically pleasing, as we have come to expect from Blueair devices with fabric pre-filters.
Good size for small to medium-sized rooms.

What we think could be better

It comes with an optical sensor instead of laser sensor, so you’re going to have to remember to clean the sensor regularly.
You will be forced to use its in-built ionizer, in the form of Blueair’s trademarked HEPASilent technology, which cannot be disabled.
With every new generation of 311 devices, Blueair introduces a new design that uses different filters, so if you’re thinking about upgrading from the old 311 Auto, you won’t be able to use any filters you might already have at home.

Clean air delivery rate (CADR):– Top speed PM1 CADR: 220 cfm
– Sub-45 dBA PM1 CADR: 108 cfm
– AHAM PM2.5 CADR: 252 cfm (dust)
Recommended room size:330 sq. ft. (5 air changes per hour)
Dimensions:19 x 12.5 x 12.5 in (48H x 32W x 32D cm)
Weight:7.87 lbs (3.56 kg)
Noise level in decibels from 3 ft. away:Sleep: 34.9 dBA
Speed 1: 37 dBA
Speed 2: 47.8 dBA
Top speed: 57.7 dBA
Electricity consumption in watts:Standby: 0.6 watts
Sleep: 2.8 watts
Speed 1: 5.2 watts
Speed 2: 13.4 watts
Top speed: 29.2 watts
Manufacturer’s warranty:2 years
Country of origin:Sweden
Country of manufacture:China

Filtration technology

The Blue Pure 311i Max features a cylindrical filter with three layers of filtration, along with an in-built ionizer.

The first layer is a washable fabric pre-filter that comes in various colors.

Blueair 311i Max Filter

The second layer is a pleated particle filter that sits underneath the fabric pre-filter.

Blueair 311i Max Particle

The third layer is a carbon-impregnated fabric that sits on the inside of the main filter.

Blueair 311i Max Carbon

In addition to mechanical filtration, the 311i Max utilizes an ionizer that electrostatically charges particles, attracting them to the filter where they are captured and removed from the air. This process generates small amounts of ozone, and unfortunately, it cannot be disabled.

Other manufacturers such as Alen, Coway, and Winix use similar ionization technologies to supercharge their particle removal speed. However, they all include buttons or app options that allow users to disable the ionizer for those who don’t want to risk introducing ozone into their air.

Controls and smart features

The 311i Max is a smart air purifier you can control with just two buttons and also from your phone.

This air purifier comes with auto mode (adjusts fan speed based on PM2.5 levels), sleep mode (quiet and with dimmed lights) and three fan speeds.

Blueair 311i Max Controls

On the back, you get a sensor that measures the level of PM2.5 particles in the air. Unfortunately, it’s just an optical sensor so you need to remember to clean it.

Blueair 311i Max Sensor

On the front, you get an air quality indicator in the form of an LED light that circles through five colors, going from blue (excellent) to red (very polluted).

Blueair 311i Max AQI

The 311i Max comes with app support through the Blueair app. I had no issues installing the app, connecting it to the device, and using it on a regular basis. From the app, you’ll be able to adjust the fan speed, set the mode (auto or night), enable the child lock, track the filter lifetime and schedule routines for the device.

Air cleaning performance

This air purifier delivers good performance at its top speed, matching our expectations based on its AHAM CADR report.

Blueair 311i Max Test

According to our PurpleAir Zen sensor, the Blueair 311i Max needed 27 minutes to achieve PM1 zero in our 728 cubic ft. test room. We estimate a PM1 CADR of 220 cfm, which matches the AHAM PM2.5 CADR result of 250 cfm.

But this information in isolation won’t tell you much, so check out how this compares to other popular mid-sized air purifiers on the market today:

The Blue Pure 311i Max completed our particle removal test faster than the much more expensive Dyson Big+Quiet BP06 (30 minutes) but slower than the cheaper Levoit Vital 200S (23 minutes).

Sound levels

Blueair 311i Max Sound

We used a sound level meter to measure how much noise each of the air purifiers we review generates at each fan speed.

At top speed, the Blueair Blue Pure 311i Max reaches 57.7 dBA. Check out the table below to see how this compares to other similarly-priced air purifiers running at top speed:

Completing our particle removal test in 27 minutes while generating only 57.7 dBA is impressive, although it doesn’t make a dent on the performance of the PC fan-powered Luggable XL-7 from CleanAirKits.

The reality however is that you are unlikely to want to run your air purifier at top speed all the time, so we found a fan speed at which the 311i Max generates less than 45 dBA of noise, which is the limit we have set for our quiet performance tests.

Running at the 311i Max at speed 1 will produce 37 dB(A) of sound, which is below the 45 dB(A) limit and close to the 40 dB(A) limit that CleanAirStars recommends for quiet classrooms and offices. At this speed, the 311I Max needed 54 minutes to complete our particle removal test:

When we repeated the test at speed 2, the device was able to reach PM1 zero in a much faster 32 minutes while generating 47.8 dBA of noise. At home, I’ve been using my 311i Max at this speed and it is louder than I would like but it is also more efficient at cleaning the air.

Long-term running costs

Running a Blueair Blue Pure 311i Max will cost you $122.19 per year, combining energy consumption costs and filter replacement prices.

As always, we used our energy meter to measure how much electricity the 311i Max uses when running at each fan speed and also while on standby. Energy consumption ranges from 2.8 watts on sleep mode to 29.2 watts when running at top speed.

This means that if you had to leave your Blueair 311i Max running 24/7 at top speed, it would cost $32.21 in energy costs for a year, using average U.S. energy rates.

Considering you need to replace the filter every six months and that the replacement costs $44.49, you can expect to also spend $89.98 per year on filters.

When compared to other similar-performing air purifiers, the 311i Max is generally cheaper to run, thanks to its low energy usage and low-cost OEM filters:

There are many generic filters available, starting at $17 per filter when you buy two. As they don’t use a HEPA grade or pelleted activated carbon the generic filters could offer a good option for those wanting to save money. We will run performance tests with a range of generic filters for our Patreon supporters.

Bottom line: Should you get the Blueair 311i Max?

A good option for those looking for a mid-sized air purifier that won’t cost an arm and a leg to run and who aren’t bothered about using an ionizer.

Blueair 311i Max

At top speed, the Blueair Blue Pure 311i Max will be faster at cleaning the air and MUCH cheaper to run than the pricier Dyson Big+Quiet BP06, so performance is very good. Even at speed 2, it can provide 185 cfm while generating 47.8 dBA of noise, which is louder than our 45 dBA limit but not by much.

Energy consumption is lower than other mid-sized air purifiers and filter replacement costs are fair, so you won’t be spending more than you should to run this device all year long.

Plus, it comes with app connectivity and an on-board air quality sensor, for those who are looking for an air purifier with smart features.

But there are two clear cases where I don’t recommend this Blueair device:

Don’t get the 311i Max if want to remove odors or chemical gases from the air The lack of pelleted activated carbon renders this model pretty useless for VOCs. Instead, look for an air purifier with large amounts of pelleted charcoal — here are my recommendations.

Don’t get the 311i Max if are wary of ionizers or don’t want to add ozone to your air. Unlike popular air purifiers like the Coway Airmega AP-1512hh or the Winix 5500-2, Blueair doesn’t include an option for users to disable the ionizer inside their devices. If this doesn’t sit well with you, then look into models from Levoit and Smart Air, or check out my list of ozone-free air purifiers.

And if you’re not set on getting a Blueair device but love the idea of a quiet and energy-efficient model, then check out the new generation of PC fan-powered air purifiers like the CleanAirKits Luggable XL (U.S.), the NorthBox Systems 6XL (Canada) and the Nukit Tempest Euro (Europe). All of these models are able to clean the air incredibly fast while generating less than 45 dBA of noise and pulling very little electricity.

If you decide to buy a 311i Max and want to support the work we do at HouseFresh, please use this link so we can earn a commission at no extra cost to you.