The Coway AP-1512HH and Alen BreatheSmart FLEX are medium-sized air purifiers with high-quality filters and outstanding performance.
The Coway has a CADR of 233 CFM (396 m³/h) and is designed for rooms up to 361 sq. ft. (33 m²). In comparison, the Alen FLEX has a CADR of 187 CFM (317 m³/h), making it suitable for spaces of up to 300 sq. ft. (28 m²).
The Coway AP-1512HH comes with a few advanced features, including an air quality sensor, an air quality indicator, and auto mode. In contrast, the Alen FLEX is a more minimalistic air purifier without advanced features.
Both air purifiers use high-quality filtration technology and are equipped with True HEPA filters. The Coway includes an ionizer as an additional filtration stage, while the Alen FLEX features a significantly better pellet-based carbon filter.
Our Verdict
I have to admit, this was a tough comparison, and determining a clear winner was not an easy task. Although the Coway AP-1512HH is one of my favorite air purifiers, I would still give a slight advantage to the Alen FLEX and declare it the winner of this comparison.
The reasons include its excellent performance, high-quality filters, the ability to choose from multiple filter options, much quieter operation, and more affordable operating costs. Overall, both are high-quality air purifiers, and even if you choose the Coway, you certainly won’t be making a mistake.
If you have any questions, feel free to leave a comment in the comment section below the article.
Specs: Coway AP-1512HH Vs Alen FLEX
| Product Image |  30% off |  |
| Manufacturer | Coway | Alen |
| Model | AP-1512HH | BreatheSmart FLEX |
| Dimensions (inches / cm) | 16.81 x 9.65 x 18.30 inches (42.7 x 24.5 x 46.5 cm) | 8.5 x 15 x 25 inches (21,6 x 38,1 x 63,5 cm) |
| Weight (pounds / kg) | 12.8 lb (5.8 kg) | 15 lb (6.8 kg) |
| Clean Air Delivery Rate (CADR) | 233 CFM (396 mÂł/h) | 187 CFM (317 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. | 361 sq. ft. (33 m²) | 300 sq. ft. (28 m²) |
| Performance Ratings Performance Ratings Score Summary: 8.3 - Average Score (100 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, Deodorization Filter, True HEPA Filter, and Ionizer | Pre-filter, True HEPA Filter, and Activated Carbon Filter |
| Filter Replacement Indicator | Yes | Yes |
| Filter Life | up to 12 months | 9-12 months |
| Power Consumption
Power Usage Summary: Our extensive testing of 100 air purifiers revealed the following power consumption insights:
Check out our power consumption calculator tool. | 77W | 50W |
| Operating Costs Ratings Operating Costs Ratings Score Summary: 8.8 - Average Score (100 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 | 3 – Speed 1, Speed 2, and Speed 3 | 4 – Speed 1, Speed 2, Speed 3, and Turbo Mode |
| Air Quality Sensor Air Quality Sensor Summary: Out of 100 air purifiers tested, only 50 have the air quality sensor. | Yes | No |
| Air Quality Indicator | Yes | No |
| Auto Mode Auto Mode Summary: Out of 100 air purifiers tested, only 51 have auto mode functionality. | Yes | No |
| Smart App Smart App Summary: Out of 100 air purifiers tested, only 29 have smart app functionality. | No | No |
| Voice Control Voice Control Summary: Out of 100 air purifiers tested, only 28 have voice control functionality. | No | No |
| Other Features | IonizerTimer | Control Panel LockTimer |
| Noise Level (low – high) | 41.4 – 63.5 dBA | 41.2 – 53.7 dBA |
| Noise Ratings Noise Ratings Score Summary: 9.2 - Average Score (100 products) 10 - Best Score (1 products) 7.6 - 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 | Pets Living Rooms Kitchens Allergies Dust | Living Rooms Bedrooms Kitchens Allergies Neutralizing VOCs Dust Mold Quiet Operation |
| Warranty | 3-year | 1-year to Lifetime |
| In-Depth Review | Coway AP-1512HH | Alen BreatheSmart FLEX |
| Price |
Performance Test – Comparison
As for performance, I tested these two air purifiers in rooms of different sizes.
The Alen FLEX uses a more powerful motor and has a higher CADR, which is why it was tested in a larger room than the Coway.
In a 560 sq. ft. (52 m²) room, after 60 minutes of operation at maximum speed, the Alen FLEX improved air quality by an impressive 94%.
Particle Removal Tests - Comparison
We placed the Coway AP-1512HH and Alen FLEX in two separate tests and measured their performance using the Temtop laser particle meter.
In contrast, the Coway AP-1512HH improved air quality by 96% in a 320 sq. ft. (30 m²) room in just 60 minutes at maximum speed.
Although these tests were performed in rooms of different sizes, we can easily conclude that both the Alen FLEX and the Coway AP-1512HH delivered outstanding results, proving why they are top-tier air purifiers and among the best in their class.
Smoke Box Test – Comparison
We tested the smoke removal performance of the Coway and Alen air purifiers.
Testing procedure: Each device was placed in a glass box, which was then filled with smoke. We measured the time required for each air purifier to completely remove the smoke from the enclosure.
The Coway AP-1512HH removed all the smoke in 18 seconds, while the Alen FLEX required 32 seconds to achieve the same result.
Clearly, the Coway AP-1512HH was significantly faster in this test.
However, what’s interesting is that the Alen FLEX features a much better carbon filter.
The reason for this outcome is that the Coway’s carbon filter has a lower density, allowing higher airflow. This enables it to move more air through the unit, which ultimately gave it the advantage in this specific test.
Noise Level Test – Comparison
Regarding the noise test, it’s worth noting that the Alen FLEX has four fan speeds, while the Coway has three. Since the Alen FLEX is one of the quietest air purifiers I’ve tested so far, the Coway didn’t stand much chance of winning this test.
To support this claim, let’s compare their noise levels at the lowest and highest fan speeds. The Coway AP-1512HH produces 41.4 dBA on its lowest speed, while the Alen FLEX measures slightly lower at 41.2 dBA.
Noise Levels - Comparison
Comparison of noise levels at all fan speeds between the Coway AP-1512HH and Alen FLEX air purifiers.
The difference becomes much more noticeable at maximum speed. The Alen FLEX produces 53.7 dBA, whereas the Coway AP-1512HH reaches 63.5 dBA.
| Fan Speed | Alen FLEX (dBA) | Coway AP-1512HH (dBA) |
|---|---|---|
| Speed 1 (Low) | 41.2 dBA | 41.4 dBA |
| Speed 2 (Medium) | 43.5 dBA | 44.6 dBA |
| Speed 3 (High) | 48.9 dBA | 63.5 dBA |
| Speed 4 (Turbo) | 53.7 dBA | - |
Clearly, the Alen FLEX is a significantly quieter air purifier than the Coway AP-1512HH.
Operating Costs – Comparison
When it comes to operating costs, the first aspect to compare is power consumption. The Coway AP-1512HH uses a 77W motor, while the Alen FLEX is equipped with a more efficient 50W motor.
This means that if both air purifiers were run at maximum speed, 24 hours a day for one month, your electricity bill would increase by approximately $2.13 with the Alen FLEX, compared to a much higher $6.05 with the Coway.
Monthly Power Consumption Cost - Comparison
Comparison of monthly power consumption costs for the Coway AP-1512HH and Alen FLEX air purifiers at all fan speeds.
In addition to electricity costs, there is also the expense of replacement filters. While Coway’s filters are slightly cheaper, this difference is largely offset by the fact that the Alen FLEX uses a higher-quality filter and consumes significantly less power during operation.
| Fan Speed | Alen FLEX (W + $/month) | Coway AP-1512HH (W + $/month) |
|---|---|---|
| Standby | 0.4W ($0.04) | 0.2W ($0.01) |
| Speed 1 (Low) | 2.7W ($0.24) | 3.6W ($0.31) |
| Speed 2 (Medium) | 6W ($0.53) | 8.1W ($0.71) |
| Speed 3 (High) | 14.2W ($1.24) | 69.1W ($6.05) |
| Speed 4 (Turbo) | 24.3W ($2.13) | - |
For these reasons, I would say that the Alen FLEX is more affordable in terms of annual maintenance costs.
Features Overview
As I indicated at the beginning of the comparison, the Coway AP-1512HH has much more advanced options than Alen FLEX, so I will devote more time to Coway in this section.
What is the most important when it comes to features is that both devices have quite enough options for optimal daily use.
Air Quality Sensor and Indicator
An air quality sensor is an option that is only available on the Coway AP-1512HH. This sensor is located on the side of the device and detects dust particles in real-time.
The sensor works in combination with other options, such as the air quality indicator. It is located on the top of the device and lights in a different color depending on the current air quality.
What I really like is that Coway offers the option to adjust the sensor’s sensitivity.
Auto and ECO Modes
In addition to the air quality indicator, the air quality sensor works in combination with Auto Mode and ECO mode options.
Basically, when in Auto Mode, the air purifier will switch the mode depending on the current air quality.
ECO mode is similar to Auto Mode, except that ECO mode turns off the air purifier if the air is excellent in the last half hour and turns it on again if the air worsens.
Filter Reset Indicator
Fortunately, both air purifiers use a filter reset indicator.
Essentially, the filter reset indicator will notify you when it is time to replace the filter, and in this way, you will not have to monitor when you need to change the filter manually.
All in all, this is a very useful option.
Timer
A timer is an option available on both devices. Essentially, the timer is used to set the time for when you want the device to shut down.
On the Coway AP-1512HH, the timer can be set to 1h, 4h, or 8h, while on the Alen FLEX, the timer can be set to 2h, 4h, or 12h.
Airflow
These two air purifiers have a very similar construction, which is why both devices have air intake vents on the front.
On both air purifiers, filtered air exits through openings on the top.
Warranty
Regarding the warranty, I have to say that Alen FLEX has surpassed Coway AP-1512HH here because it comes with a lifetime warranty.
Coway, on the other hand, comes with a 3-year warranty, which is quite ok.
Filtration Technology
As these two are top-notch air purifiers, it’s somehow expected that they have high-quality and extremely efficient filters. Luckily, I did performance tests on these two air purifiers, in which I confirmed that they have incredibly efficient filters.
The Coway AP-1512HH uses 4-stage filtration consisting of a washable pre-filter, True HEPA filter, activated carbon filter, and ionizer. What’s good is that the ionizer is turned off by default, so if you don’t feel like you don’t have to use it. In addition, Coway is CARB certified, which means it does not produce unallowed amounts of ozone.
Alen FLEX uses 3-stage filtration technology consisting of a pre-filter, a True HEPA filter, and an activated carbon filter. I like Alen because it offers as many as three different filter options, and the most massive filter contains as much as 2+ lbs of carbon pellets.
I want to mention that Alen has slightly thicker filters, but they don’t last longer than Coway’s.
How to Replace Filters?
Since these two air purifiers do not use washable filters, except for the pre-filter on Coway, it is necessary to change the old filters from time to time.
That period averages about 12 months for Coway and between 9-12 months for Alen. It is commendable that both devices use a filter reset indicator, so you will not have to monitor when it is time to replace the filter.
I have described the detailed process of replacing the filters in the individual reviews that you can find at the links below.
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