In today’s article, I will compare the Alen FLEX and Winix 5500-2 air purifiers. These two outstanding devices offer impressive performance and excellent specifications.
Each has its pros and cons, but only one stands out as the better buying option. I will analyze performance test results, noise levels, and power consumption, along with comparing their specifications, to determine which one is the superior choice.
Additionally, the Alen FLEX is a more modern device, while the Winix 5500-2 boasts more advanced features. Winix also has a slightly higher CADR.
Our Verdict
I must say that this is one of the most challenging comparisons I have ever made.
Not only are both of these air purifiers outstanding performers, but they also share many similarities.
In my opinion, the Winix 5500-2 is a slightly better buying option than the Alen FLEX. Why? It performed slightly better in our airborne particle removal tests, was faster in our smoke test, and features a washable pre-filter and activated carbon filter. Additionally, it comes with more advanced features and is initially a much more affordable device.
However, the Alen FLEX stands out for its quiet operation, excellent performance, and low maintenance costs—so you won’t go wrong choosing this model either.
If you have any questions about these two air purifiers, feel free to leave a comment in the section below the article.
Specs: Alen FLEX Vs Winix 5500-2
| Product Image |  |  |
| Manufacturer | Alen | Winix |
| Model | BreatheSmart FLEX | 5500-2 |
| Dimensions (inches / cm) | 8.5 x 15 x 25 inches (21,6 x 38,1 x 63,5 cm) | 15 x 8.2 x 23.6 inches (38.1 x 20.8 x 59.9 cm) |
| Weight (pounds / kg) | 15 lb (6.8 kg) | 15.4 lb (7 kg) |
| Clean Air Delivery Rate (CADR) | 187 CFM (317 m³/h) | 232 CFM (394 m³/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. | 300 sq. ft. (28 m²) | 360 sq. ft. (33 m²) |
| Performance Ratings Performance Ratings Score Summary: 8.4 - Average Score (79 products) 9.8 - Best Score (2 products) 2.5 - Worst Score (2 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, True HEPA Filter, and Activated Carbon Filter | Washable Pre-filter, Washable AOC Carbon Filter, and True HEPA Filter |
| Filter Replacement Indicator | Yes | Yes |
| Filter Life | 9-12 months | up to 12 months |
| Power Consumption
Power Usage Summary: Our extensive testing of 79 air purifiers revealed the following power consumption insights:
Check out our power consumption calculator tool. | 50W | 70W |
| Operating Costs Ratings Operating Costs Ratings Score Summary: 9 - Average Score (79 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 – Speed 1, Speed 2, Speed 3, and Turbo Mode | 5 – Sleep Mode, Speed 1, Speed 2, Speed 3, and Turbo Mode |
| Air Quality Sensor Air Quality Sensor Summary: Out of 79 air purifiers tested, only 39 have the air quality sensor. | No | Yes |
| Air Quality Indicator | No | Yes |
| Auto Mode Auto Mode Summary: Out of 79 air purifiers tested, only 40 have auto mode functionality. | No | Yes |
| Smart App Smart App Summary: Out of 79 air purifiers tested, only 25 have smart app functionality. | No | No |
| Voice Control Voice Control Summary: Out of 79 air purifiers tested, only 24 have voice control functionality. | No | No |
| Other Features | Control Panel LockTimer | PlasmaWaveLight SensorRemoteTimer |
| Noise Level (low – high) | 41.2 – 53.7 dBA | 40.6 – 66.4 dBA |
| Noise Ratings Noise Ratings Score Summary: 9.3 - Average Score (79 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 Kitchens Allergies Neutralizing VOCs Dust Mold Quiet Operation | Pets Living Rooms Kitchens Allergies Smoke Dust Neutralizing VOCs |
| Warranty | 1-year to Lifetime | 2-year |
| In-Depth Review | Alen BreatheSmart FLEX | Winix 5500-2 |
| Price | Check Price on Amazon | Check Price on Amazon |
Performance Test – Comparison
Although these two air purifiers have different CADR ratings, both delivered outstanding results in our airborne particle removal tests.
The Alen FLEX has a CADR of 187 CFM (317 m³/h), making it ideal for rooms up to 300 sq. ft. (28 m²), while the Winix 5500-2 has a CADR of 232 CFM (394 m³/h), making it ideal for spaces of up to 360 sq. ft. (33 m²).
Even though they are designed for different room sizes, we didn’t test them in the same conditions.
In the first test, we placed the Winix 5500-2 in a 320 sq. ft. (30 m²) room, in which it improved air quality by 96% in just 60 minutes.
Particle Removal Tests - Comparison
We placed the Alen FLEX and Winix 5500-2 in two separate tests and measured their performance using the Temtop laser particle meter.
On the other hand, the Alen FLEX improved air quality by 94% in a 560 sq. ft. (52 m²) room.
Both air purifiers were tested at their maximum fan speeds for 60 minutes.
Overall, the Winix 5500-2 is slightly better at airborne particle removal, while the Alen FLEX is more efficient and excels at eliminating odors and gases.
Smoke Box Test – Comparison
The Alen FLEX’s higher concentration of carbon pellets in its filter didn’t help it achieve a faster result in our smoke test.
However, that doesn’t mean it’s less effective at removing odors. In fact, while the Alen FLEX has a higher density of carbon pellets, it also has a lower CADR. This means that although it takes longer to remove odors, it may actually be more effective over time.
In our test, the Winix 5500-2 cleared all the smoke from the glass box in just 20 seconds, while the Alen FLEX took approximately 32 seconds.
Noise Level Test – Comparison
The Alen FLEX has four fan speeds, while the Winix 5500-2 has five. The Winix also features a sleep mode, which the Alen FLEX lacks.
However, at its lowest speed, the Alen FLEX is quieter than many air purifiers in sleep mode.
Noise Levels - Comparison
Comparison of noise levels at all fan speeds between the Alen FLEX and Winix 5500-2 air purifiers.
It produces only 41.2 dBA, whereas the Winix 5500-2 operates at 40.6 dBA in sleep mode. Additionally, the Alen FLEX is a SleepScore-certified air purifier and one of the best devices we recommend for bedrooms.
| Fan Speed | Alen FLEX (dBA) | Winix 5500-2 (dBA) |
|---|---|---|
| Sleep Mode | - | 40.6 dBA |
| Speed 1 (Low) | 41.2 dBA | 42.7 dBA |
| Speed 2 (Medium) | 43.5 dBA | 44.9 dBA |
| Speed 3 (High) | 48.9 dBA | 50.3 dBA |
| Speed 4 (Turbo) | 53.7 dBA | 66.4 dBA |
At maximum speed, the Winix 5500-2 reaches 66.4 dBA, while the Alen FLEX remains significantly quieter at 53.7 dBA.
Overall, the Alen FLEX stands out as a much better-optimized air purifier in terms of noise levels.
Operating Costs – Comparison
Regarding operating costs, the first thing I want to compare is power consumption. The Alen FLEX has a 50W motor, while the Winix 5500-2 has a 70W motor.
This means that if you ran both air purifiers at maximum speed, 24 hours a day, for one month, your electricity bill would increase by approximately $5.08 for the Winix 5500-2, whereas the Alen FLEX would cost about $2.13.
Monthly Power Consumption Cost - Comparison
Comparison of monthly power consumption costs for the Alen FLEX and Winix 5500-2 air purifiers at all fan speeds.
Both air purifiers have filters that last around 12 months on average. However, keep in mind that the Winix 5500-2 features washable pre-filters and activated carbon filters.
| Fan Speed | Alen FLEX (W + $/month) | Winix 5500-2 (W + $/month) |
|---|---|---|
| Standby | 0.4W ($0.04) | 1.2W ($0.11) |
| Sleep Mode | - | 3.7W ($0.32) |
| Speed 1 (Low) | 2.7W ($0.24) | 6.4W ($0.56) |
| Speed 2 (Medium) | 6W ($0.53) | 8.8W ($0.77) |
| Speed 3 (High) | 14.2W ($1.24) | 13.2W ($1.16) |
| Speed 4 (Turbo) | 24.3W ($2.13) | 57.9W ($5.08) |
Since the filter prices are nearly the same and both models offer plenty of third-party filter options, I would say that, due to its significantly lower power consumption, the Alen FLEX is the more cost-effective option in terms of maintenance.
Features Overview
Some basic options like a Timer are common for both of the appliances.
With the Alen FLEX, you can set the timer to 2hrs, 4hrs, or 12hrs, while the Winix 5500-2 allows setting a timer to 1hrs, 4hrs, or 8hrs. So, this feature will provide you with the possibility to set the time for which the air purifier will shut down.
Considering the price of the Alen FLEX, I expected it to be equipped with more advanced options. But that’s not a big deal.
On the other hand, Winix turned out to be quite a surprise. An Air Quality Sensor, Remote Controller, and Auto Mode are just some of the many features Winix has.
Smart Sensor and Air Quality Indicator
OK, this is something I was talking about in the previous section. I’m a bit disappointed with the fact that the Alen FLEX doesn’t have Smart Sensor and Air Quality Indicator features.
When it comes to Winix 5500-2, its sensor can only detect odors. You can spot it at the right corner, below the Smart Sensor indicator.
The Air Quality Indicator is immediately below the PlasmaWave indicator, and as long as the light is blue, your air is good. Keep an eye on it before it turns out red if you want your face muscles free from grimaces.
Yet another helpful feature is Auto Mode, which controls the speed of your air purifier depending on the current air quality.
Despite the fact that the Smart Sensor can’t detect dust particles, I honestly think it makes Winix very competitive.
Filter Reset Indicator
If you took a look at the comparison table at the beginning of the article, I’m sure you have noticed that both these air purifiers have a Filter Reset Indicator.
This feature will inform you when it’s time to replace your air purifier’s dirty filter.
With Alen FLEX, you get something like traffic lights. As long as the Filter Reset Indicator light is green, you’re good to go. As soon as it turns yellow, you’ve been warned that the time of replacement is soon to come. The red light of the indicator means you should STOP and replace the filter ASAP.
Winix does it in a far less complicated way. The minute the indicator lights up, the filter is ready to be replaced.
Now I wonder which one would you prefer!?
PlasmaWave
In the Air Quality Indicator section, I mentioned that Winix 5500-2 has something called PlasmaWave.
It is actually the fourth stage of filtration or so-called Ionizer, which Alen FLEX doesn’t happen to have.
It is a good option to have, but the one thing that bothers me is that the PlasmaWave is turned ON by default the minute you start your purifier. Of course, you can always press the button and turn it OFF, but I really think, as an extra feature, it should be left optional to the user whether to use it or not.
Luckily, the Winix is CARB certified air purifier, which assures it won’t be producing illicit amounts of ozone.
Lock
Here’s an interesting feature that you can use on your Alen FLEX purifier, that Winix is missing.
Almost like a child-lock on your laundry machine, you get to lock all the other buttons on your appliance. You have to press and hold your finger for 5 seconds on the “Lock” button, and it will immediately do its job, enabling your air purifier to work fluidly without the possibility of something or someone interfering.
Airflow
Since both units are rectangular, it is not surprising that their filters are set in the front.
They both draw in the air through the openings on the front, which is then filtered and exit through the grilles on the top of devices.
Warranty
Let’s talk about what type of coverage you get for purchasing one of these appliances.
I was surprised to find out that the Alen FLEX offers you a lifetime warranty. What you need to do, to comply with the lifetime warranty is to register on the Alen website and subscribe to a regular filter replacement. Keep in mind that if you at least register your purchased product on the Alen website, you will get a 5-year warranty.
Even though I’m not a fan of a buyer being conditioned in any kind, I do think this is the way to ensure the long-lasting of your appliance.
Although Winix does not ask you to register the product or to buy replacement filters regularly, it does come with a significantly shorter, 2-year warranty.
Filtration Technology
If you’ve read carefully, then you are familiar with an extra filtration stage that Winix 5500-2 has, and that is the PlasmaWave.
This extra feature is what differs the two devices, since both of them have the same prior three stages, such as pre-filter, True HEPA filter, and an Activated Carbon filter. The pre-filter and the activated carbon filter are washable in the case of Winix 5500-2.
A bit smaller yet 0.7 inches thicker filter is the point where Alen FLEX is different from Winix. Also, you get to buy 3 different versions of carbon filters, whereas they come in various weights. The heaviest carbon filter contains over 2 lbs of carbon which is great because, the more carbon it has, the more odors it can adsorb.
The fact that these air purifiers use carbon pellets makes them so efficient, both in practical usage and in testing results.
How To Replace Filter On Both These Devices?
This is the part where you get to be your own handyman. If you want your purifier to last long, you will need to check up on filters as instructed. As you can see, filter life is approximately the same for both Alex FLEX and Winix 5500-2, which is about 9 to 12 months.
I would recommend cleaning the pre-filters regularly, at least once per month. By keeping it clean you not only prolong the longevity of other filters but also keep the level of filtration at its highest.
Actually the Allen markets their flex to clean 700 ft², but in 30 minutes. The Winix shows 435 ft² in 15in. So in reality the Winix cleans 870 sq ft in 30 min, more than the Allen. I noticed when shopping Allen markets all of their square footage in 30 minutes. Most other companies go by 15 minutes or even by 5 changes an hour. So they always appear much lower.