As I’ve been testing some new devices from Blueair, new options have opened up for fresh comparisons and direct head-to-head tests between Blueair air purifiers.
The Blueair DustMagnet 5240i is a compact, modern, and somewhat innovative air purifier. It stands out for its dual-filter design, smart features, sleek design, and very good performance.
On the other hand, the Blueair 511i Max features the familiar design we’ve come to expect from the Blue Pure series, along with smart features and excellent performance.
The Blueair DustMagnet 5240i has a CADR of 137 CFM (233 m³/h), while the Blueair 511i Max has a CADR of 152 CFM (258 m³/h) — yet another parameter that shows just how similar these two devices are.
Our Verdict
All in all, both of these are high-quality, reliable, and worthwhile air purifiers.
However, the Blueair DustMagnet 5240i achieved noticeably better results in all key tests, making it the better overall choice.
The only area where the Blueair 511i Max has an advantage is in its lower annual maintenance costs, but unfortunately, that’s not enough for it to take the win in this comparison.
If you have any questions about these two air purifiers, feel free to leave a comment in the comments section below.
Specs: Blueair DustMagnet 5240i Vs Blueair 511i Max
| Product Image |  |  14% off |
| Manufacturer | Blueair | Blueair |
| Model | DustMagnet 5240i | 511i Max |
| Dimensions (inches / cm) | 8.6 x 8.6 x 20.5 inches (22 x 22 x 52 cm) | 10.6 x 10.6 x 18.9 inches (26.9 x 26.9 x 48 cm) |
| Weight (pounds / kg) | 9.9 lb (4.5 kg) | 4.2 lb (1.9 kg) |
| Clean Air Delivery Rate (CADR) | 137 CFM (233 mÂł/h) | 152 CFM (258 mÂł/h) |
| Coverage (4.8 ACH)
Room Coverage Explanation: ACH is a measurement used in indoor air quality management to indicate how many times the air within a defined space is changed/moved through the filter media.
For more details, visit our ACH calculator tool. | 212 sq. ft. (19.7 m²) | 236 sq. ft. (22 m²) |
| Performance Ratings Performance Ratings Score Summary: 8.3 - Average Score (91 products) 9.9 - Best Score (1 products) 1 - Worst Score (1 products) We use the Temtop LKC-1000S laser particle meter to test the particle removal efficiency of every air purifier. It measures PM2.5 (µg/m3), PM10 (µg/m3), Particles (per/L), and HCHO (mg/m3) in the air, and also calculates the AQI. You can read more about our testing methodology here. | ||
| Filtration Technology | Pre-filter, Carbon Filter, Particle Filter, and HEPASilent | Washable Pre-filter, Particle Filter, Activated Carbon Filter, and HEPASilent |
| Filter Replacement Indicator | Yes | Yes |
| Filter Life | 6-12 months | up to 9 months |
| Power Consumption
Power Usage Summary: Our extensive testing of 91 air purifiers revealed the following power consumption insights:
Check out our power consumption calculator tool. | 22W | 20W |
| Operating Costs Ratings Operating Costs Ratings Score Summary: 9 - Average Score (91 products) 10 - Best Score (2 products) 1.7 - Worst Score (1 products) We measure the power usage at all speeds using an energy meter, after which we calculate how much it would cost to use the device at a particular fan speed for one month. For reference, we use an energy price of $0.12 per kWh. You can read more about our testing methodology here. | ||
| Number of Fan Speeds | 4 - Sleep Mode, Speed 1, Speed 2, and Speed 3 | 4 - Sleep Mode, Speed 1, Speed 2, and Speed 3 |
| Air Quality Sensor Air Quality Sensor Summary: Out of 91 air purifiers tested, only 44 have the air quality sensor. | Yes | Yes |
| Air Quality Indicator | Yes | Yes |
| Auto Mode Auto Mode Summary: Out of 91 air purifiers tested, only 45 have auto mode functionality. | Yes | Yes |
| Smart App Smart App Summary: Out of 91 air purifiers tested, only 26 have smart app functionality. | Yes | Yes |
| Voice Control Voice Control Summary: Out of 91 air purifiers tested, only 25 have voice control functionality. | Yes | Yes |
| Other Features | Night Mode | Washable Pre-filter |
| Noise Level (low – high) | 40.1 – 52.6 dBA | 40.1 – 61.6 dBA |
| Noise Ratings Noise Ratings Score Summary: 9.3 - Average Score (91 products) 10 - Best Score (1 products) 8.2 - Worst Score (1 products) We use a special noise measurement tool to test the noise level of the air purifier at all speeds. We measured the noise level on the dBA scale. You can read more about our testing methodology here. | ||
| Best Suited For | Living Rooms Bedrooms Allergies Dust Smart Home Integration Quiet Operation | Bedrooms Allergies Small Spaces Dust Low Energy Cost |
| Warranty | 5-year | 3-year |
| In-Depth Review | Blueair DustMagnet 5240i | Blueair 511i Max |
| Price |
Performance Test – Comparison
Since these two models have almost identical CADR ratings and cover rooms of similar sizes, we tested their performance in rooms with the same dimensions.
The Blueair DustMagnet 5240i is rated for spaces up to 212 sq. ft. (19.7 m²), while the Blueair 511i Max can handle rooms up to 236 sq. ft. (22 m²).
Particle Removal Tests - Comparison
We placed the Blueair DustMagnet 5240i and Blueair 511i Max in two separate tests and measured their performance using the Temtop laser particle meter.
In a test performed in a 320 sq. ft. (30 m²) room, both air purifiers delivered excellent results. After just 60 minutes of operation at maximum speed, the Blueair DustMagnet 5240i improved air quality by about 92%, while the Blueair 511i Max improved it by around 90%.
However, when it came to neutralizing unpleasant odors, the Blueair DustMagnet 5240i performed noticeably better, which is likely due to its higher-quality carbon filter.
Overall, I’d conclude that the Blueair DustMagnet 5240i is slightly more efficient than the 511i Max.
Noise Level Test – Comparison
Both air purifiers have the same number of fan speeds. We tested noise levels at each speed, and overall, they’re almost equally quiet, except at maximum speed, where the Blueair 511i Max is significantly louder.
Noise Levels - Comparison
Comparison of noise levels at all fan speeds between the Blueair DustMagnet 5240i and Blueair 511i Max air purifiers.
At the lowest speed, both the Blueair DustMagnet 5240i and the 511i Max produce 40.1 dBA. However, at maximum speed, the DustMagnet produces 52.6 dBA, while the 511i Max reaches 61.6 dBA.
Not only is the Blueair 511i Max noticeably louder, but it also emits a faint crackling sound during operation, which can be quite irritating — especially at maximum speed.
| Fan Speed | Blueair DustMagnet 5240i (dBA) | Blueair 511i Max (dBA) |
|---|---|---|
| Sleep Mode | 40.1 dBA | 40.1 dBA |
| Speed 1 (Low) | 40.1 dBA | 41.3 dBA |
| Speed 2 (Medium) | 43.5 dBA | 44.1 dBA |
| Speed 3 (High) | 52.6 dBA | 61.6 dBA |
All in all, I’d say that the Blueair DustMagnet 5240i is better optimized for noise.
Operating Costs – Comparison
Blueair is well-known for optimizing its air purifiers for low energy consumption, and that’s also true for these two models.
The DustMagnet 5240i uses a motor of just 22W, while the Blueair 511i Max uses a 20W motor.
If you were to run both models 24 hours a day for an entire month, your electricity bill would increase by about $1.68 for the Blueair DustMagnet 5240i and around $1.56 for the Blueair 511i Max.
Monthly Power Consumption Cost - Comparison
Comparison of monthly power consumption costs for the Blueair DustMagnet 5240i and Blueair 511i Max air purifiers at all fan speeds.
That’s an extremely small cost and a clear sign of how efficiently both devices are optimized for power usage.
However, there’s another cost to consider, replacement filters, which need to be changed roughly once or twice per year for both units.
| Fan Speed | Blueair DustMagnet 5240i (W + $/month) | Blueair 511i Max (W + $/month) |
|---|---|---|
| Standby | 0.7W ($0.06) | 0.6W ($0.05) |
| Sleep Mode | 3.7W ($0.32) | 1.9W ($0.17) |
| Speed 1 (Low) | 3.9W ($0.34) | 2.5W ($0.22) |
| Speed 2 (Medium) | 7.4W ($0.65) | 4.7W ($0.41) |
| Speed 3 (High) | 19.2W ($1.68) | 17.8W ($1.56) |
The price of replacement filters is noticeably more affordable for the Blueair 511i Max, which, combined with its very low power consumption, makes it significantly cheaper to maintain annually than the Blueair DustMagnet 5240i.
Leave a Reply