Coway Airmega 300S Review: Smart air purifier that works with Alexa!

Last updated on April 19th, 2021

The starters

A modern and quality air purifier from Coway. Airmega 300S is basically 300 with added Wi-Fi integration. Sharing the same dimension at 13.6 x 21.2 x 13.6 in/ 21.4 lb weight, the build quality is second to none. Front design is as clean as it gets with one prominent LED ring indicator. The air quality indicator will lit in blue and green when surrounding indoor air quality is good. Green and yellow when indoor air is moderate. Yellow and pink when indoor air is unhealthy. Finally, pink and red when indoor air is very unhealthy. Instead of just one back air inlet in typical design, 300S has dual air inlet that sucks air on both sides. Speaking of that, you will also find two handles on each side of the air purifier for easy transporting.

Airmga 300S is unlike most air purifier that places its control panel at front. Its controls are located at the top black panel that is only accessible up close. Separated into two sections, On the left, you will find a Wi-Fi, Light, Pre Wash, and Max2 change button. Wi-Fi button enables connection to nearby Wi-Fi network. The Wi-Fi LED indicator will blink when there is no connection or undergoing pairing. Once the air purifier is connected to a Wi-Fi network, the LED light will stay constant. Next to it is the light button that activates/ deactivates AQ indicator light. The bottom two buttons (Pre Wash/ Max2) will lit once the filters require cleaning (Pre Wash) or change (Max 2). To reset the button indicator light, press and hold the buttons for 2-3 seconds. The small Light sensor is not a button, it is used to detects the intensity of the surrounding light. If the dark condition stays more than 3 minutes, Sleep mode will activate. This function can be overwritten if the air purifier is not in Smart mode (manual speed).

Continue to the right, you have a big Power button, a small Air speed/ mode button, and five small indicator light. The power button will obviously turn on/ off the air purifier (hold for 2-3 seconds). Airspeed/ mode button will cycle between the 3 fan speed, Smart mode, and Sleep mode. Here’s a secret function that many people are unaware of. The air purifier pollution sensor’s sensitivity level can be adjusted. First, press and hold to the light button, then press the Air speed/ mode button repeatedly until the desired sensitivity is selected. 1 fan bar = sensitive, 2 fan bar = normal, 3 fan bar = less sensitive.

Here is where the differences play it part. Airmega 300S comes with Wi-Fi support which allows you to manage your air purifier via IoCare App. Available in iTunes/ Google Play, pairing is straightforward for iPhone and Android phones. Through IoCare app, you can remotely control the fan speed or switch to Smart/ Sleep mode. There is also real-time air monitoring and Indoor/ Outdoor Air Quality Report. Timer and scheduler is a separate function. For timer, it comes with pre-set 1, 2, 4, 8 hours setting. For the scheduler, it is our favorite where you could program up to weekly schedule for the air purifier. Also works with Amazon Alexa where you could link it via devices like Amazon Echo. Standard list of voice command includes on/ off, Smart/ Sleep mode, fan speed, set timer, check filter life status and air quality.

To repeat, here are the standard features available in the air purifier. A 4 stage filtration, Smart mode (Auto/ Sleep/ Eco), and 3 fan speed. Wi-Fi enabled with IoCare app/ Alexa support. Separate pre-filter/ HEPA filter indicator based on runtime. Scheduler/ timer, air quality indicator. Lastly, 30 days satisfaction money back guarantee, and 5 years manufacturer warranty.

Airflow, speed, and CADR

Comes in standard 3 speed + Smart/ Sleep mode, Airmega 300S has a decent airflow performance. At 1256 sq. ft. with 2 air charges every 30 minutes and 628 sq. ft. with 4 air charges every 15 minutes. There is still plenty of airflow punch even if you opt for the higher 4 air charges purifying speed. Pollution sensor functions accurately thanks to the adjustable sensitivity. Smart mode will automatically set the right speed based on surrounding air quality. Sleep mode would set to a lower speed for reduced noise and power. Great for residential home at living hall, basement or even bedroom (with Sleep mode). Airmega 300S CADR is also equally impressive at a rounded high 260 cfm for dust, pollen, and smoke. There are no differences in airflow performance VS 300, but there is a clear gap between the 400 series. Nonetheless, anything above 200 cfm would be good enough for indoor irritants.

What’s inside count

The familiar 4-stage filtration setup that can be found in every other Airmega models. Coway Airmega 300S works exactly like 300 with dual Pre-filter on both sides. Whenever the air purifier pulls air in, the pre-filter will block out the large particles. This leaves only the small particles alone the journey and that's where the True HEPA filter comes in. The Green True HEPA filter would trap allergens as small as 0.3 microns with an effective rate of 99.97%. With only smoke particles left, the last-stage Activated Carbon filter would kick in. At a successful rate of 99%, nearby smoke and odor contaminants will be well-contained. No ionizer is intact, so the filtration relies on the quality of the Max2 filters.

Keep it down

Airmega 300S 22 - 52 dB noise level might not be the quietest air purifier around, is good enough for most occasion. It is considerably silent at sleep/ low speed and audible background noise at max speed. You can still use the air purifier in a bedroom although it's a little bit overkill for its capacity. Power consumption wise, 6 - 57 watts is not too shabby given the number of airflow output. Expect even lower consumption if this Energy Star unit engaged in Auto/ Sleep mode. Autonomous will prevent the fan speed from going above unless the air quality is not at an ideal level. Also, there is Eco mode where the motor fan will stop spinning when the air quality is good for at least 10 minutes.

At what cost

Coway Airmega 300S is not your typical budget-friendly model with cut-down specification. In fact, it is the complete opposite thus is even pricier than its peer model. Is the Wi-Fi enabled feature worth the extra dollar for an identical spec to Airmega 300? Only you can decide. On to maintenance, the mandatory filter change is not the most pricey in its class but is not cheap either. You need to replace the Max2 filter set on a yearly basis or when is depleted. When the time comes, the filter can be easily purchased online as availability is good.

Airmega 300S VS the challengers

Other Airmega Air Purifiers