Blueair 121 vs 211

Blueair 121 and 211

Covid-19 has limited all of us to our homes. It has provided you with the opportunity to focus on yourself. However, staying at home for too long can affect the air quality of the house.

Do you ever feel trapped or suffocated in the house? Trust me. Nothing is wrong with your lungs, as Google may suggest. It is just because the air inside your house is crawling with harmful air pollutants. However, the pollutants are potentially hazardous for your health if inhaled for extended periods. Therefore, you need to choose the best air purifier because it’s about your own health. In this regard, Blueair is a well-known brand that provides high-quality air purifiers at an affordable price.

All Blueair products are unique and powerful as compared to others. However, Blueair 121 vs. 211 is a consistent debate all over the internet. It is because both of these units provide unmatched performance, durability, and air quality. So, customers are often confused as to which of these devices is suitable for them. So, in this article, I will compare the Blueair 211 and 121 to help you choose the perfect device.

Overview [ Short answer ]

If you don’t have the time to read the whole article, I’ll just give you a straightforward answer. In my opinion, Blueair 121 is a bit more superior than the 211. Factual data based on the specifications show that Blueair 121 performs better even in larger rooms and quickly improves the air quality of the house.

However, it won’t be wise to underestimate Blueair 211 air purifiers. It still outperforms some of the top-notch air purifiers in the world. In fact, the 211 air purifier was the premium device until the 121 came along. Still, some people prefer it even over the 121 due to its reliability and low power consumption. So, if you want a trusted device with thousands of positive reviews, you can also go with the Blueair 211 air purifier.

Now I will provide a more detailed comparison as well as the similarities between the two beasts. So, you can decide for yourself and don’t have to take my word for the most important device in the house.


Quick Comparison between Blueair 121 & 211

Features  Blueair 121  Blueair 211
Coverage 600 Sq. Ft 550 Sq. Ft
Filter indicator Yes Yes
Fan speeds  3 3


Similar features of these two beasts

Each year Blueair releases an array of new products with some upgrades and improvements. However, the brand follows a strict rule of quality over quantity. So, you should expect the best air purification technology in all their products.


Simple and elegant design:

It is hard to distinguish between a modern air purifier and a gaming PC. The main reason is the fancy designs, inappropriate sizes, and the numerous unnecessary LEDs that you get. Moreover, most air purifiers require a dedicated space in the house for their so-called proper air filtration. Blueair is different from other air purifier brands. They provide simple designs with universal placement. It means that you can place this device anywhere in the house, and still, it won’t affect its performance or usability.

Similarly, both 121 and 211 air purifiers are designed to enhance the elegance of your house. There is some hidden beauty in the simple design of these air purifiers that many find attractive. Moreover, you don’t have to deal with the complex settings and the never-ending buttons on the control panel. Who needs those panels anyway? Blueair units provide the same functionality with just a single-button control panel. It is a multifunctional button that you can use to power the device, change fan speed and reset the filter indicator after replacement.


3-stages of filtration:

Air purifiers have greatly evolved since the first unit in the 1900s. Modern air purifiers use a combination of several latest technologies to purify the air from all air pollutants, smoke, odor, and even germs. All air purifiers use the most advanced HEPA filter to remove even the tiniest particles without disturbing the airflow in the room. Like others, Blueair devices also use a similar method but with several improvements. The air purification system consists of:

  • Pre-filter: The air filtration starts soon as the air is sucked into the device. First, the air passes through a mechanical filter known as the pre-filter. This filter has openings small enough to remove larger particles of dust, pet hair, plastic, dander, and some pollen. Moreover, this filter is permanent, and you can rinse it after a thorough vacuum cleaning every month. The filter lasts at least 5-years before losing its quality. You can easily replace the pre-filter as it doesn’t cost over 20 bucks.
  • Silent HEPA: The second phase of air filtration is when the air passes through the advanced HEPA filter. This portion removes up to 0.03-micron particles, including dust mites, dander, molds, and some chemicals from the air with 99.97% accuracy. However, Blueair has found a way to improve even this perfect air filter with silent HEPA technology. I will explain the wonders of this technology in a bit. The HEPA filter is disposable, and you need to change it every 6-months. The filter replacement indicator starts blinking red when it is time for a replacement.
  • Activated Carbon filter: This is the most important air filter that several brands often ignore. This filter comprises numerous carbon-catching particles. The filter acts as a magnet to catch all organic pollutants from the air, including VOCs, chemical fumes, paint fumes, and odor molecules. Moreover, the filter is upgradable with an even more powerful silver version that even removes some harmful germs and bacteria from the air. You need to replace the activated carbon filter whenever you replace the HEPA filter as they come in a combo.


What is silent HEPA?

You might be wondering; the air is already silent during filtration. Let’s start from the basics. Have you ever heard of air sanitizers? These are electrical devices that convert oxygen into volatile ions to kill all microorganisms from the air. The problem with this technique is that the unused oxygen ions bond with O2 molecules to form ozone. Ozone is a notorious greenhouse gas that damages the environment and causes global warming.

Blueair uses an improved version of sanitization technology to keep you safe without damaging the environment. These air purifiers combine the ionizer and HEPA filter to produce the silent HEPA technology. Instead of producing oxygen ions, the electric plates induce a positive charge on the air pollutants. Meanwhile, the HEPA filter is negatively charged. As you know, opposite charges attract, so all negatively charged particles stick to the HEPA filter while the clean air leaves without any problem. The pollutants are collected on one side of the HEPA to allow greater airflow. Therefore, Blueair purifiers provide some of the highest CADR scores when compared to other products


Uninterrupted sleep:

Another problem with other air purifiers is that they produce too much noise. Sometimes your ears start ringing when you turn off the air purifier, or you have to speak up when it is running. Blueair understands the need for silence in your life. The powerful yet efficient fans of this device produce far less noise than other devices. Furthermore, the silent HEPA technology of 211 and 121 air purifiers allows better airflow without drawing more power from the motors. As a result, these devices produce as little as 32dB noise at low fan speed and 52dB noise at the highest speed.

Such noise level is as low as a human whisper and rustling leaves. Moreover, some users find the sound relaxing and necessary for better sleeping. Therefore, it is no harm to keep the device running even during sleep. The clean air of the room promotes a healthy sleep cycle and less snoring. A major sign of peaceful sleep is when you wake up on the same side of the bed that you slept. So, you can test for yourself if your sleep cycle improves by using one of these air purifiers in the house.

Similarly, the power light in the button doesn’t disturb your sleep as well. The light dims after 7-seconds and turns off after 15-minutes of inactivity. Therefore, even that little LED won’t disturb your peaceful sleep.



Most people use Blueair air purifiers in their homes. The typical air purifier can add a lot to your monthly electricity bill. It is because the noisy fans run too fast, and the motor is not optimized to promote energy efficiency. On the contrary, Blueair 121 and 211 air purifiers are optimized to provide maximum performance without drawing much power. In fact, all Blueair products are Energy-Star certified for low power consumption. According to experts, these devices use the same amount of power as a light bulb. So, you can save as much as 40% on your electricity bills by using one of these devices.

Similarly, Blueair purifiers are best for commercial usage as well. You can set up multiple devices to cover the whole office or hall, and still, it won’t cost you as much as other air purifiers. Similarly, you can save some extra cash by setting the device to run at low fan speed. Although it takes a bit longer to clear the room, the unit becomes more efficient as the air quality of the room improves.


Color customization:

Everyone gets bored from looking at the same color for several years. Moreover, some people have to replace the air purifier just because it doesn’t match the color scheme of their newly painted house. However, Blueair gives you the option to customize its color according to your needs. The pre-filter is located on the outside of the device. This filter comes in up to 5-colors to choose from. You can easily replace the colored pre-filter according to your taste without spending more than 20-30 bucks. Thus, instead of buying a new air purifier, you can improve the one that you already own.


Filter replacement indicator:

Almost all modern air purifiers come with a filter replacement indicator. However, some brands even cut off this little LED sensor to increase their profit margin. Blueair is driven by customer satisfaction rather than falsely advertising its products to increase sales. All Blueair air purifiers come with a built-in filter replacement indicator. This sensor is integrated within the single control button at the center of the device. You can’t always keep track of the last filter replacement all the time. Therefore, the light starts blinking red as soon as it is time to replace the HEPA filter with a new one. The replacement filter doesn’t cost more than 15-20 dollars, and the issue doesn’t come back for another 6-months. However, you need to manually reset the filter replacement indicator to reset its count down.


Blueair 121 vs. 211: The differences:

By now, you must understand why any Blueair air purifier is better than other brands. Now that you’ve decided that you want one, the next problem is which one to choose. Blueair has a device that fits every budget and space requirement. However, the 211 & 121 are the most effective and premium devices of them all. Here are a few differences to help you figure out the perfect device for your needs:

Air coverage:

The first thing that you should consider when choosing an air purifier is its coverage area. Sometimes even the most powerful device is not suitable for effectively cleaning the air in the whole house. It is due to several reasons like air filters, the air output, and the CADR ratings. Blueair 121 can cover up to 600 Sq. Ft rooms in under 30-minutes. The powerful 400 CFM ratings ensure that fresh air reaches the far corners of the house.

On the other hand, Blueair 211 provides a slightly lower coverage area. It can clear the air in up to 550 Sq. Ft rooms in under 30-minutes. However, the air coverage improves as you keep the device running for 1-hour or more. Similarly, the 350 CFM airflow is far more superior to even some high-end devices in the market. So, you’re mistaken if you think that Blueair 211 is any less efficient than 121.

Another great thing about these air purifiers is the ACH ratings. Usually, air purifiers run 2-3 times per hour to clear the room. This score is good but still not enough to efficiently keep the air quality within safe limits. However, Blueair wins the stage in this case as well; Ahref individually approves all their products to provide 5x cleaning every hour. Again the Blueair 121 covers more area in each cycle as compared to the 211 models.  So, Blueair 121 beats the 211 models in every possible ground.

The extra filter:

Blueair 121 and 211 are pretty similar devices in terms of functionality and features. Except for the extra protection that gives the 121 its upper hand over the competition. The air is often filled with odorous molecules and even removing those particles isn’t enough. The odorless air is safe to breathe, but it still lacks a touch of freshness. Therefore, Blueair 121 uses advanced activated carbon filter coconut pallets. The filter is fat more efficient than the typical carbon filter in removing organic compounds. Moreover, the coconut pallets add freshness to the air.

When air passes through this improved carbon filter, the odorous molecules are caught within the carbon-catching compound. However, it leaves behind an empty space that you need to fill with an appropriate fragrance. The coconut pallets fill these voids with a fresh, tropical fragrance. Several users claim that this new filter has greatly improved their focus as well as their sleep cycle.

On the contrary, Blueair 211 doesn’t come with any such extra filter. So, you are forced to use an air freshener to make the atmosphere fresh and healthy.

The pros and cons:

Surely both Blueair 211 and 121 are powerful devices. They have several similarities in the working principle as well as features. However, the devices come with their pros and cons.

Blueair 211 pros Blueair 121 pros

AHAM verified

Lower noise levels


Better CADR: 400CFM

Low power usage

Extra coconut-carbon filter

Silent HEPA technology 

Silent HEPA technology 

Coverage: 550 Sq. Ft

Larger coverage area: 600 Sq. Ft

Customizable pre-filter 

Colorful washable pre-filter 

Blueair 211 Cons Blueair 121 Cons

It doesn’t come with the extra coconut-carbon filter

It doesn’t have Wi-Fi or auto mode. 

The device doesn’t have auto mode. 

The device is slightly expensive than the 211.


Filter replacement

Blueair 121

A single replacement filter lasts anywhere between 8-12 months. The smart indicator will start blinking red light when the filter requires replacing. You can get the genuine filter replacement for Blueair 121 here

Blueair 211

The filter replacements indicator will let you know when it is time to replace. Usually, a single replacement filter lasts for 8-months, but I recommend that you change it every 6-months. You can buy the replacement filters from here



Blueair 121 is the ultimate winner in the 121 comparisons. It offers several performance improvements as well as an extra protection filter. However, the Blueair 211 is still an effective choice for its high coverage area, low power consumption, and high CADR scores.




Is it safe to use Blueair air purifiers while sleeping?

Yes, all Blueair devices are ozone-less as they don’t come with ionizers. So, you can keep it on even during sleep. According to experts, the Blueair purifiers can improve your sleep cycle and minimize snoring.


Do all Blueair purifiers have an extra filter?

No, only the Blueair 121 allows you to replace the activated carbon-particle filter with the improved coconut-carbon filter. This filter removes even the dense odor from the air and replaces it with a fresh fragrance.


Does Silent HEPA remove germs?

Yes, silent HEPA is a combination of ionizer and HEPA filter. It induces a charge on the air pollutants and an opposite charge on the polymer HEPA. The oppositely charged particles, including germs and bacteria, are efficiently removed from the air. Furthermore, the fast CADR combined with the induced charge deactivates the viruses and makes it easy to remove them.


I'm Julia, an air purification expert and certified Indoor Air Quality Professional. With a Master's in Environmental Science and a decade of research at the National Institute for Environmental Health Sciences, I've dedicated myself to understanding air pollutants and their health impacts. At 'PureAirly', my mission is to leverage my expertise in air purifiers and guide you towards cleaner, healthier air.

1 thought on “Blueair 121 vs 211”

  1. I will be buying two Blueair purifiers–one a 121, and a smaller one for our bedroom– in Jan. My rep Camillio in Chicago was WONDERFUL
    in teaching me about how it can help us feel SO MUCH BETTER, and ESPECIALLY our PETS, who are our important family members. But now I have concerns about this coconut filter that gives not just a FRESHNESS to the air, but a fresh TROPICAL FRAGRANCE to the air/whole house. What does this fragrance do to asthmatics and others who CANNOT have natural or chemical fragrances in ANYTHING. Is this a type of allergen that many boast about thate warn of NATURAL AND ORGANIC-NON CHEMICALS that can make us more ill with allergic and respiratory reactions??? Serious question. Can we get filtering WITHOUT that fragrance?? RSVP.


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