Coway Airmega 300 Review: Is this cheapest Airmega air purifier any good?
Airmega 300 Specification
Product | Airmega 300 |
Dimension | 13.6 x 21.2 x 13.6 in (34.5 x 53.8 x 34.5 cm) |
Weight | 21.4 lb (9.7 kg) |
Fanspeed | 3 |
Coverage (up to) | 1256 sq. ft. (117 m2) |
Airflow speed | |
Dust free (CADR) | 260 cfm (442 m3/h) |
Pollen free (CADR) | 260 cfm (442 m3/h) |
Smoke free (CADR) | 260 cfm (442 m3/h) |
Filtration | 4-stage |
Pre-Filter - Lifespan - Replacement cost ($) | Pre-filter (2 pack) Permanent +- 25 |
HEPA filter - Lifespan - Replacement cost ($) | Max2 (Green True HEPA filter) 1 year |
Carbon filter - Lifespan - Replacement cost ($) | Max2 (Activated carbon filter) 1 year |
Ionizer/ Technologies | |
UV-light/ PCO | - |
Other filter | - |
All-in-one filter - Lifespan - Replacement cost ($) | Max2 Filter 1 year +- 99.99 |
Optional/ Addon | - |
Noise level | 22 - 52 dB |
Power usage level | 6 -57 W |
Timer/ Scheduler | 1, 4, 8 hours |
Sensors | Pollution sensor |
Auto mode | |
Air qualityAQ indicator | |
Filter change indicator | |
More color options | |
Wi-Fi/ BTBluetooth | |
ENERGY STAR | |
Remote control | |
Child lock | |
Warranty | 5 years |
Email/ Phone support |
Key features
- 4-stage filtration
- Dual washable Pre-filter
- MAX2 filter (True HEPA filter + Activated Carbon filter)
- 3 fanspeed (Low, Medium, High)
- Dual side air inlet
- Dedicated Pre-filter and HEPA filter indicator
- Smart mode - Auto, ECO and Sleep mode
- Air quality display indicator (Good, Moderate, Unhealthy, Very Unhealthy)
- Customizable pollution sensor (1 bar = sensitive, 2 bar = normal, 3 bar = less sensitive)
- Built-in timer (1, 4, 8 hours)
- 5 years warranty
Pros
- Very wide purifying coverage despite being the least expensive in its series.
- Dual pre-filter that traps large particles coming from both sides. Also protect and extent the inner filter lifespan.
- Excellent allergens and smoke filtration via its Green True HEPA/ Carbon filter.
- Auto mode that is sensitive to surrounding air quality.
- Separate Pre-filter and MAX2 filter lifetime indicator.
- Built-in timer without having to rely on the app.
- Clear and accurate real-time air quality display indicator.
- Acceptable annual Max2 filter replacement cost for its higher-end category.
- 5 years official warranty from Coway.
Cons
- Still expensive despite being the cheapest model in the group.
- After online discounted price, you only need to top up a little bit more for the Wi-Fi version (300S).
- Lacks autonomous sleep mode and real-time filter replacement indicator found in 400/ 400S models.
- No Ionizer as an additional filtration option.
The starters
Skip this section if you have gone through 300S review. A modern piece of artwork, Airmega 300 shares the exact dimension as other Airmega models. At 13.6 x 21.2 x 13.6 in and 21.4 lb weight including the legs, it is considerably bulky. You have the dual integrated sides air inlet, two side handles, and top black control panel. At front, there is a circle air quality indicator that will display in four different colors. By default, the ring indicator is in blue when indoor air quality is good. The color will shift to purple when air quality drop to moderate, Pink when is unhealthy, and Red when is very unhealthy. On the whole, build quality and fitting are right on top with no signs of ozone or off-gassing. No problem getting this air purifier for the long-haul.

Most air purifier that has a centrally aligned control panel. Coway Airmega 300 controls are segregated to 2 sections. On the left part, you will find a Timer button, Light button, Pre Wash button, and Max2 change button. Timer button comes with 1, 4, 8 hours pre-set setting that will cycle between them on click. “Lightbulb” Light button will either enable/ disable the front air quality indicator light. The bottom two buttons (Pre Wash/ Max2) will only lit when the filters require change (Max 2) or clean (Pre Wash). To reset either of the filter indicator light, press and hold the buttons for 2-3 seconds. There is also a small light sensor that measures the surrounding light intensity. It will automatically switch to Sleep mode when there is no light source in a room for more than 3 minutes. You can deactivate the Sleep mode by setting it to manual mode (non-Smart mode). As for the right part of the controls, you will find two main buttons that manage the entire operation. The prominent one is the power button which turns on or off (hold for 2-3 seconds) the air purifier. The less prominent button control the fan speed or cycle between Sleep or Smart mode.
One neat trick that most people didn’t know, the pollution sensor’s sensitivity can be tuned. To start, press and hold the Light + Air speed/ mode button. Once active, press the Air speed/ mode button repeatedly until you selected the preferred sensitivity. 1 fan bar = Sensitive, 2 fan bar = Normal, 3 fan bar = Less sensitive.
To recap, standard features in 300 include a 4 stage filtration, 3 fan speed, and “Smart” Auto, Sleep, Eco mode. AQ indicator, built-in timer (1, 4, 8), and separate pre-filter/ HEPA filter indicator that based on run time. End with 30 days money back guarantee and 5 years warranty.
Airflow, speed, and CADR
What’s inside count
Equipped with the same filter quality from its series, Airmega 300 4-stage filtration is very dependable. As air flows in from left and right, the dual pre-filter would cover both sides of the air intake. Dust, hair, and other large particles would be trapped while on the way in. With smaller particles sneaked pass the pre-filter, the "genuine" Green True HEPA filter is ready and waiting. Any allergens or microorganisms as small as 0.3 microns will be halt from proceeding. For chemical smoke and gases, you have the reliable Activated Carbon filter standing by. All that missing from the filtration list is an optional ionizer. Despite its commonality, most people can live without it.Keep it down
At what cost
^ Replacement filters/ estimated cost
Airmega 300 VS the challengers

Airmega 300S
Adds remote control feature and Coway app support features. 300S is the more expensive option to go for if you want the essence of Airmega with added Wi-Fi connectivity.
Airmega 400
Identical model but upped in airflow performance and coverage. There is also a real-time pre-filter/ HEPA filter usage calculator. You do have to trade-off with a bigger dimension and a much higher cost.
Coway AP-1512HH Mighty
Coway Mighty air purifier is definitely not at the same level. You do get more than adequate airflow circulation for large room size. Also cost way less to own and maintain with a proven HEPA + Carbon filtration set.