Blueair 311i Max Air Purifier – High CADR, Low Energy Use

Full Review

We tested another air purifier from the Blueair Blue Pure series — the 311i Max.

This model looks identical to the Blueair Mini Max and Blueair 511i Max, which we tested some time ago and whose reviews you can also find on the website.

However, what sets the Blueair 311i Max apart is its much larger filter, larger overall dimensions, and significantly higher CADR.

How all of this affects its rating, performance, and overall impressions of the Blueair 311i Max air purifier is something you’ll discover in the rest of this review.

How We Tested the Blueair 311i Max?

1. For the filter efficiency testing, we used the Temtop LKC-1000S laser particle meter, which measures PM2.5 (µg/m3), PM10 (µg/m3), Particles (per/L), and HCHO (mg/m3) in the air, and also calculates the AQI.

2. We placed the Blueair 311i Max in two separate performance tests, one in a 320 sq. ft. (30 m²) room and the other in a 560 sq. ft. (52 m²) room. Then, we recorded the initial air quality values using the Temtop laser particle meter and let the Blueair 311i Max run at maximum speed.

3. After 60 minutes, we measured the new values using the Temtop laser particle meter and saved the data.

4. Next, we placed the Blueair 311i Max in a glass box, which we then filled with smoke. Then, we measured how much time was needed for the air purifier to remove all the smoke from the box.

5. Using a special noise measurement tool, we tested the air purifier’s noise level at all speeds. We measured the noise level on the dBA scale.

6. Finally, we measured the power usage at all speeds using an energy meter, after which we calculated how much it would cost to use the device at a particular fan speed for one month. For reference, we used an energy price of $0.12 per kWh.

As with every air purifier we’ve tested so far, we also evaluated the performance of the Blueair 311i Max in rooms of predefined dimensions using a Temtop laser particle meter.

What’s interesting about the Blueair 311i Max is that it delivered excellent results in capturing airborne particles, but it lagged a bit when it came to neutralizing bad odors.

This is primarily because the Blueair 311i Max uses a fibrous filter coated with carbon, rather than a pellet-based carbon filter, which is generally much more efficient, higher quality, and delivers significantly better odor-neutralization performance.

To keep it short, it’s best that you take a look at the detailed test results this air purifier achieved.

Testing in a 320 sq. ft. (30 m²) Room

In the first test, in a 320 sq. ft. (30 m²) room, which is slightly smaller than the recommended size, the Blueair 311i Max delivered a fantastic result.

We let it run for 60 minutes at maximum speed, and during that time, it improved the air quality by an impressive 96%.

For comparison, this result is on the same level as some of the best air purifiers we’ve tested, such as the Levoit Vital 200S or the Coway AP-1512HH.

All in all, I would say that the Blueair 311i Max is an extremely efficient and powerful air purifier.

Testing in a 560 sq. ft. (52m²) Room

In the test performed in a room slightly larger than the recommended size, the Blueair 311i Max also delivered an excellent result.

In just 60 minutes of running at max speed, in a 560 sq. ft. (52 m²) room, the Blueair 311i Max improved air quality by about 89%, which is a very good result and comparable to some of the best air purifiers we’ve tested.

It reduced PM2.5 particulate matter from 100.8 to 10.4 µg/m³.

This simply proves that the Blueair 311i Max is effective even in rooms that are somewhat larger than the recommended dimensions.

The Blueair 311i Max uses a motor that’s very well optimized for noise, has four fan speeds, and is generally a quiet air purifier.

At the lowest speed, it produces 40.2 dBA, which is excellent and on par with some of the quietest air purifiers we’ve tested so far.

For comparison, the Blueair 211+ produces around 43.9 dBA at its lowest speed.

However, the situation becomes a bit more complicated at maximum speed. Even though the Blueair 311i Max is one of the best-optimized air purifiers in terms of noise (compared to similar air purifiers—see the chart) and produces 59.5 dBA, not everything is perfect.

The problem is that at maximum speed the motor creates a strange buzzing sound that is very irritating, and despite the good noise optimization, this buzzing really spoils the overall experience.

Although the Blueair 311i Max is generally a very quiet air purifier, I still wouldn’t give it an excellent rating. To earn that, the buzzing issue would need to be resolved.

In almost every review I write about a product from Blueair’s Blue Pure series, I highlight how well these devices are optimized for power usage.

With a motor of only 30W, this air purifier delivers an impressive CADR of 250 CFM (425 m³/h), which is quite remarkable for a device of this size.

If you were to run the Blueair 311i Max at maximum speed, 24 hours a day, for an entire month, your electricity bill would increase by about $2.42, placing it among the best-optimized air purifiers we’ve tested.

For comparison, the Winix 5510 would cost around $4.68 under identical conditions, which is a huge difference considering they have very similar CADR values.

Aside from electricity costs, you also have the cost of replacement filters, which need to be changed roughly every 6 to 9 months. For an air purifier and filter of this size, that’s an acceptable lifespan, although I’ve seen many similarly sized devices with filters that last much longer.

All in all, I’d say the Blueair 311i Max is very well optimized, and the only downside I see here is the somewhat more frequent filter replacement.

Filtration Technology

The Blueair 311i Max uses Blueair’s traditional HEPASilent technology, which combines mechanical and electrostatic filtration.

This results in somewhat better performance, but as a side effect it does produce ozone.

This air purifier uses a four-stage filtration system, of which only the particle filter and activated carbon filter are replaceable.

The filter takes up almost three-quarters of the device, which is a big advantage, and its 360-degree air inlet allows it to capture particles from all sides.

Pre-filter

The first stage of filtration is the pre-filter, which is essentially a fabric sleeve that fits over the main filter.

The primary purpose of this filter is to capture large particles such as dust, hair, pet hair, and similar debris.

In this way, it improves the overall filtration performance and also helps protect and extend the lifespan of the main filter.

What’s especially good about this pre-filter is how easy it is to clean, so easy that you can simply place it in the washing machine without any problems.

Particle Filter

The main and most important stage of filtration is the particle filter. It’s essentially a mechanical filter, but it works in combination with HEPASilent technology to achieve the highest possible effectiveness.

The particle filter captures small airborne particles such as dust, pollen, mold spores, smoke, and similar pollutants.

However, I can’t say that its efficiency is on the level of a True HEPA filter, but it is still effective for almost any household.

Activated Carbon Filter

The third stage of filtration is the activated carbon filter, which, to be honest, is not the best solution.

The Blueair 311i Max uses a fibrous filter coated with carbon, which has consistently proven to be much less effective than a pellet-based carbon filter.

The best devices we’ve tested for smoke removal use pellet-based carbon filters. For example, the Austin Air HealthMate Jr. has as much as 6.5 lb of carbon pellets inside, which is why it’s one of the best air purifiers for smoke.

Don’t expect miracles from the Blueair 311i Max’s carbon filter, but you can expect it to neutralize very light odors — and that’s about it.

Ionizer (HEPASilent)

HEPASilent™ is a technology unique to Blueair air purifiers. It’s their patented system.

This technology combines mechanical and electrostatic filtration in a way that maximizes overall efficiency.

According to the Blueair website, this combination effectively removes at least 99.97% of airborne particles as small as 0.1 microns, which is a very high level of efficiency.

However, the issue is that this technology produces ozone as a byproduct. Although the levels do not exceed permitted limits, it’s important to mention this fact.

Personally, I avoid using ionizers because I think they’re unnecessary and that a HEPA filter does a perfectly good job without the use of ionization.

What matters here is that Blueair does produce ozone, but in amounts far below the allowed limit, and the device is CARB-certified, which is strong proof that it is safe to use. The choice is yours.

How to Replace the Blueair 311i Max Filter?

As I already mentioned in the review, the filters in the Blueair 311i Max typically last between 6 and 9 months.

However, the actual lifespan of the filters largely depends on how the device is used and the environment in which it operates. In rooms with pets, the filter will get dirty much faster.

When it’s time to replace the filters, only the particle and carbon filters need to be changed. The pre-filter is washable — it doesn’t need to be replaced, only cleaned or washed about twice a month.

The filter replacement process is extremely simple and requires only a few basic steps.

Setup and Installation

As for the initial setup before first use, it’s also very simple—mainly because the Blueair 311i Max comes fully ready to run, with the filters already installed.

All you need to do is connect the air purifier to the smart app, if you want to (which I highly recommend), and that’s it.

Now just place the device in your desired location, plug it in, and turn it on.

Design

When it comes to design, all I can say is that this is one of the most beautiful air purifiers I’ve used. In fact, the entire Blueair Blue Pure series is perfectly balanced and modern.

The Blueair 311i Max is essentially made up of two parts: the top section, which takes up about one-quarter of the unit and houses the motor and controls, and the bottom section, which is basically the frame that holds the filter.

What I really like is that the pre-filter covers almost three-quarters of the device and is available in several different colors, giving you the option to easily match the Blueair to your interior.

As for build quality, it’s nothing extraordinary, but it is more than good enough for this type of product.

Controls and Indicators

When it comes to controls, the Blueair 311i Max has a control button and indicators on the top panel.

Here, you’ll find the power button as well as the button for switching fan speeds. The indicators include fan speed indicators, a Wi-Fi indicator, and indicators for Night Mode and Auto Mode.

On the front side of the device, near the top, there is an air quality sensor that lights in different colors depending on the current air quality in the room.

Airflow

When it comes to airflow, the Blueair 311i draws air in through openings positioned on all sides — it has a full 360° air inlet.

The air is then filtered and released through the vents on the top of the device.

Size and Dimensions

The dimensions of the Blueair 311i Max air purifier are 19 x 12.5 x 12.5 inches (48 x 32 x 32 cm), and it weighs just 7.8 lb (3.56 kg).

Overall, it’s a slightly larger air purifier, which makes moving it from one room to another a bit more challenging.

What’s in the box?

When you buy the Blueair 311i Max, you will get the air purifier, a pre-installed filter, and a user manual.

Features Overview

At first glance, the Blueair 311i Max may look like a very minimalist and simple air purifier.

However, it is a very powerful device equipped with a wide range of advanced features.

Air Quality Sensor & Indicator

One of the most important smart features is definitely the air quality sensor. Its purpose is to measure the amount of airborne particles in real time.

This sensor detects the concentration of PM2.5 particles in the air, and based on that information, several other features of the device operate.

For example, the air quality indicator will light in different colors depending on the current level of air pollution.

What’s important to know is that this sensor works even when the device is turned off, which means that if you connect the air purifier to the smart app, you can check the current air quality at any time—even when the purifier itself isn’t running.

Auto Mode

Auto Mode is another feature that works in combination with the air quality sensor.

Essentially, when Auto Mode is enabled, the air purifier adjusts the fan speed based on the current air quality.

If the air is heavily polluted, Auto Mode will switch the purifier to maximum speed. As the air quality improves, Auto Mode will gradually reduce the fan speed.

Overall, this is a very useful option for anyone who prefers a more automated experience.

Night Mode (Sleep Mode)

When you switch the Blueair 311i Max to Night Mode, it will dim all indicators and reduce the fan speed to the lowest setting.

In this way, you’ll barely notice the air purifier running, and if you use it in a dark room, you won’t see it at all because all of its lights will be dimmed.

Warranty

The Blueair 311i Max comes with a one-year warranty, but if you register the air purifier directly on Blueair’s website shortly after purchase, you can extend the warranty to three years.

Honestly, very few manufacturers offer a warranty longer than two years, so this is a big plus and something I would recommend to everyone.

Blueair Smart App

Blueair really put effort into making the best possible smart app, and they succeeded — this is one of the best air purifier apps I’ve had the chance to use.

Connecting the device to the app is extremely simple and only requires following the on-screen instructions. There are no connection drops, and I haven’t seen any negative feedback regarding device pairing.

The app unlocks many advanced features, including detailed real-time and historical air quality data, remote control, an advanced timer, and perhaps most interesting of all — voice control.

Another thing that stood out to me is the fan speed slider. Not only can you select a specific fan speed, but you can also use it like a potentiometer, meaning you can set the fan speed to something between two preset levels.

Overall, this is a very advanced app, and I would say it has almost no downsides.

FAQ on Blueair 311i Max