Blueair DustMagnet 5240i Air Purifier – Hands-on Review

Full Review

Blueair frequently changes its product lineup, and I believe it’s the brand that has released the most different air purifiers so far.

The only drawback in all of this is that every few years, they discontinue some models, either because sales didn’t go as planned or for some other reason I’m not entirely sure of.

This time, my focus will be on the Blueair DustMagnet 5240i. It’s a small air purifier, primarily intended for bedrooms, featuring a dual-filter system and an attractive design.

We tested its performance, noise levels, and power consumption, and in this review, I’ll describe it in detail and determine whether it’s worth buying or not.

How We Tested the Blueair DustMagnet 5240i?

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 DustMagnet 5240i in a 320 sq. ft. (30 m²) room. Then, we recorded the initial air quality values using the Temtop laser particle meter and let the Blueair DustMagnet 5240i 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 DustMagnet 5240i 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.

We tested the airborne particle removal performance of the Blueair DustMagnet 5240i to determine how effective it really is.

In addition to the predefined room tests, where we evaluate all air purifiers, I also used the Blueair DustMagnet 5240i in my bedroom for some time.

What impressed me the most was the air quality improvement I experienced, even at the lowest fan speed, while the device was almost silent. That’s truly decent!

On top of that, I noticed it does a pretty good job at neutralizing bad odors. It’s not as effective as, for example, the Austin Air HealthMate Jr., but it handles light odors quite well.

Testing in a 320 sq. ft. (30 m²) Room

In the first test, performed in a 320 sq. ft. (30 m²) room, the Blueair DustMagnet 5240i delivered fantastic results.

In just 60 minutes of operation at maximum speed, it improved air quality by an impressive 92%.

It reduced the concentration of PM2.5 particles in the air from 105.2 to 8.1 µg/m³, which I measured with a Temtop laser particle meter.

Compared to the competition and similar devices, it’s easy to see that the Blueair DustMagnet ranks at the very top as one of the most efficient air purifiers (see chart).

For example, in the exact same test, the Blueair 511i Max improved air quality by about 90%, while the Bosch Air 2000 achieved around 89%.

All in all, the Blueair DustMagnet 5240i is a highly effective and well-built air purifier.

When it comes to the noise level test, the first thing I’d point out is that the Blueair DustMagnet 5240i has four fan speeds plus an auto mode.

Using a specialized tool to measure noise levels on the dBA scale, we measured the noise output at each speed.

What’s interesting is that the Blueair DustMagnet 5240i delivered fantastic results, making it one of the quietest air purifiers we’ve had the chance to test.

At the lowest speed (sleep/night mode), it produces just 40.1 dBA. For comparison, the Levoit Core 300S produces 41.4 dBA at its lowest speed.

At maximum speed, the results are also excellent. The Blueair DustMagnet 5240i produces only 52.6 dBA, which places it among the best-optimized air purifiers on our list.

Check out the chart I included, where I compared it with some competitors—it speaks for itself.

For example, the Winix A231 produces 66.5 dBA, which is significantly louder than the Blueair DustMagnet at max speed.

Overall, I’d say the Blueair DustMagnet 5240i is very well-optimized for noise at all fan speeds.

When it comes to power consumption, this is another aspect of the air purifier that deserves praise. With a motor rated at just 22W, the Blueair DustMagnet 5240i delivers a solid CADR of 137 CFM (233 m³/h).

Thanks to its low-power motor, at maximum speed, this model consumes only about 19.2W. This means that if you were to run it 24 hours a day for an entire month, your electricity bill would increase by just around $1.68, which I consider a relatively small expense.

Compared to the competition, this cost is much lower than with most other air purifiers. For instance, under identical conditions, the Coway Airmega 150 would cost you about $2.52.

Of course, in addition to electricity costs, there’s also the expense of replacement filters, which need to be changed on average every 6–12 months.

Although the replacement filters are not so cheap, which is expected, since this model uses a dual-filter system, their durability helps justify the price.

In conclusion, while the replacement filters are somewhat pricey, the energy consumption is extremely low. For that reason, I’d say the Blueair DustMagnet 5240i is not the cheapest to maintain annually, but it’s certainly far from expensive.

Filtration Technology

The Blueair DustMagnet 5240i uses a dual three-stage filter system along with HEPASilent technology.

This air purifier combines mechanical filtration with electrostatic filtration to deliver the best possible performance.

The filters are positioned at the bottom and top of the device, making them easy to replace and even easier to clean.

Overall, I can say that the Blueair DustMagnet 5240i uses high-quality filtration technology, and you’ll notice an improvement in your home’s air quality in a very short time.

Pre-filter

When I think about it, until now I’ve only tested Blueair air purifiers from the Blue Pure series, which use fibrous pre-filters. This is the first Blueair air purifier I’ve tested with a different type of pre-filter.

The pre-filter is the first stage of filtration, and what’s interesting is that it’s electrically charged, meaning it attracts particles and thereby improves overall filtration efficiency.

This filter is not washable, but it does need to be cleaned from time to time, about twice a month, or more frequently if you plan to use the air purifier in a room with pets.

Carbon Filter

What surprised me about this model is the fact that it uses a pellet-based carbon filter as the second stage of filtration.

I’m usually used to seeing Blueair rely on fibrous filters coated with carbon, which makes this a big plus for the brand.

The carbon filter is primarily responsible for neutralizing bad odors, smoke, VOCs, and similar gases in the air.

Particle Filter

Probably the most important stage of filtration is the particle filter, whose main purpose is to capture small airborne particles such as dust, pollen, mold spores, allergens, and similar pollutants.

Although it doesn’t use a True HEPA filter, when combined with HEPASilent technology, Blueair often achieves results that are equal to, or even much better than, devices that do use True HEPA filters.

All in all, I’m absolutely sure that this stage is the main reason for the outstanding performance this model delivered in our tests.

HEPASilent

The final stage of filtration is the HEPASilent technology, which is essentially an ionizer that is always on and can’t be turned off.

This stage significantly contributes to the filtration efficiency of the device but produces ozone as a byproduct. However, it’s important to note that it is CARB and EnergyStar certified, meaning it doesn’t produce ozone in unsafe amounts.

The ionizer works by releasing negative ions that attach to free particles in the air (such as dust), causing them to become heavier and fall to the ground. In this way, it helps reduce airborne allergens, dust particles, and similar pollutants.

To be honest, I generally prefer air purifiers without ionizers, but I still believe the Blueair DustMagnet is safe to use, especially considering that it’s CARB certified.

Setup & Installation

This small air purifier requires a bit of setup before the first use.

The first step is to check whether the filters are unpacked; if not, remove the packaging and place them back into the device.

Next, take the legs and screws from the shipping box and attach them to the bottom of the unit. That’s all you need to do.

Finally, place your Blueair DustMagnet 5240i in the desired location, making sure to keep it away from walls or other objects, plug it in, and turn it on.

Design

As I already mentioned in this review, the Blueair DustMagnet 5240i is one of the most beautifully designed air purifiers I’ve had the chance to use.

It features an unusual design that reminds me much more of a piece of furniture than of an air purifier.

In fact, it’s also designed to function as a small table, so you can place items like a book, phone, or other small objects on top.

The build quality is quite good; it’s made primarily of plastic, with part of the unit covered in fabric.

It’s compact, lightweight, and easy to move from one room to another.

All in all, I believe the Blueair DustMagnet 5240i will blend seamlessly into almost any interior or living space.

Controls and Indicators

In addition to smart controls via the Blueair Smart App, the Blueair DustMagnet 5240i also features physical controls located in the top-right corner of the device.

Here you’ll find touch buttons with all the essential functions, as well as indicators that show which option is currently active.

Although the controls are well laid out and easy to use, I believe that with the smart app connection, you’ll rarely need to rely on the physical buttons.

Airflow

The Blueair DustMagnet 5240i has a very interesting airflow design, which is somewhat different from standard air purifiers.

This device draws air in from both the bottom and top, filters it, and then releases it through the sides.

It’s important to ensure that the airflow is not blocked when positioning the unit, as doing so could potentially damage the device.

Size and Dimensions

This is a relatively small air purifier, measuring 8.6 x 8.6 x 20.5 inches (22 x 22 x 52 cm) and weighing 9.9 lb (4.5 kg).

As I already mentioned, it’s compact and lightweight, so you’ll have no trouble moving it from room to room.

What’s in the box?

When you purchase the Blueair DustMagnet 5240i, you’ll receive the device itself, two 3-in-1 filters, a power adapter, legs with screws, and a user manual.

Features Overview

The Blueair DustMagnet 5240i is a smart air purifier equipped with plenty of advanced features.

It seems that Blueair integrates smart app compatibility into almost all of its new air purifiers.

The only relatively new model without this option is the Blueair Mini Max.

Air Quality Sensor & Indicator

The Blueair DustMagnet 5240i uses a PM2.5 air quality sensor that measures the concentration of airborne particles in the air.

This sensor collects real-time air quality data and works in combination with several other features.

For example, the current air quality is shown through the indicator on the front of the device, which glows in different colors depending on the air quality level.

In addition, the air quality is displayed much more precisely through the smart app.

All in all, this is a very catchy feature that takes the Blueair DustMagnet to a completely new level.

Auto Mode

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

When set to auto mode, the air purifier automatically adjusts the fan speed based on the current air quality.

In essence, when the air quality is poor, the device increases the fan speed to maximum, and when the air quality is good, it lowers the speed, continuously adapting as conditions change.

Night Mode

This is a very useful feature for anyone planning to use the air purifier in a bedroom.

With just one press of the night mode button, the device lowers the fan speed to the minimum and dims all indicators.

Filter Reset Indicator

This indicator is a great feature that notifies you when it’s time to replace the filter.

The indicator is located directly on the device, but you’ll get a much more detailed view of filter usage and status through the smart app.

Warranty

The Blueair DustMagnet 5240i comes with a one-year warranty, which can be extended to five years if you register the device with Blueair within 60 days of purchase.

Blueair Smart App

Blueair uses an advanced smart app to control its air purifiers. This app not only enables remote control but also unlocks many additional features available only when the device is connected to it.

The app is available for both Android and iOS devices. I tested it on iOS and can say it worked flawlessly.

Pairing the app with the air purifier went smoothly, without any issues, and the whole process was completed within a few minutes.

Once connected, the first thing you’ll see on the purifier’s dashboard is a detailed real-time air quality report, along with a history of air quality readings.

In addition, there’s an advanced slider for adjusting fan speeds, plus quick-access controls for night mode, child lock, and auto mode.

Another feature I really like is the ability to adjust the brightness of the indicators and set up an advanced timer directly through the app.

All in all, the Blueair smart app takes the DustMagnet 5240i to a much higher level of usability and convenience.

Room Coverage and CADR

With a CADR of 137 CFM (233 m³/h), the Blueair DustMagnet 5240i is ideal for rooms up to 212 sq. ft. (19.7 m²). In a space of this size, the air purifier will clean the air 4.8 times per hour.

This also means that in a room of 1,017 sq. ft., the Blueair DustMagnet will be able to clean the air once per hour.

That said, I always recommend using an air purifier within its suggested room size. I wouldn’t place it in larger spaces than recommended—unless the air quality in the room is already relatively good.

FAQ on Blueair DustMagnet 5240i