Coway AIRMEGA 400S Air Purifier Review

Coway AirMega 400S Air Purifier Review

With a lot of problems that we face with regard to climate and many such manmade disasters, it is very important to know the fact that the quality of air that we breathe in has significantly deteriorated over a period of time. With an immense number of products to make sure that we breathe quality air within, many companies have come up with the concept of using air purifiers inside homes to maintain the air quality from within. 

One such company, Coway is a health-obsessed firm which aims to keep the health & fitness maintained and away from the air pollutants and airborne. The Company was founded in 1989 and has remarkably marked their presence in the market providing quality purified air devices, water devices, health and fitness devices across the globe. With diligence servicing the product, Coway is honoured with the award for its product and home health expertise to the US with Coway Bidet Mega for bathrooms, Coway Airmega air purifiers, and Coway Aqua Mega water purifiers. 

Today, Coway is the global leader in engineering and innovation, intensive research, and amassing over 4,700 intellectual property rights. Now prior to the Coway Mega 400S, there were a lot of other products that were released by Coway as well like the Coway 200 M, Coway AP-1512HH, Coway 1512 HHS and the Coway AIRMEGA +Alexa. 

These products definitely made an impact in the ways that the world perceived air purifiers, the company has got a huge revenue of the sales from the already existing products. Coway decided to step up the game and went on with the release of the Coway AIRMEGA 400s Air purifier that had a lot of inclusive details than the existing products and that went under our rigorous testing platform. If you’re looking for other air purifiers for large spaces, you can read our dedicated review of air purifiers for large spaces.

Coway Airmega 400S Review

Coway AIRMEGA 400S Air Purifier Review
1. Area Coverage 1560 Sq. Ft.
2. Fan SpeedSleep, Low, Medium, High
3. Filtration EfficiencyRemoves 99.97% of particles greater than 0.3 microns
4. Max. CFM (airflow in Cubic Feet per Minute)410 CFM at “High” speed
5. CADRCADR Dust: 350; CADR Smoke: 350; CADR Pollen: 350
6. Noise43.2 dB at the highest setting; resembles light rainfall
7. Power ConsumptionEnergy Star Certified – 64 watts on highest speed
8. Filter TypeTrue HEPA
9. Filter Life12 months
10. Warranty 5 Year Limited


  • Rated to cover an area of up to 1560 sq. ft.
  • Can easily take out gaseous pollutants, toxic fumes and cigarette smoke alongside suspended solid particles in air
  • The filter indicator tells if it’s time to replace the primary filter
  • The pre-filter is washable/reusable
  • 1-year limited warranty for internal malfunctions and 5-year for motor and electronic parts


  • Has a considerably big footprint

Check Latest Price

Top Air Purifiers Comparison Table

Air Purifier
Filter Type
Filter Life
1. Coway AirMega 400S
12 Months
1,560 Sq. Ft.
5 years
Check Price
2. Austin Air HealthMate+
60 Months
1,500 Sq. Ft.
5 years
Check Price
3. IQAir HealthPro Plus
48 Months
1,125 Sq. Ft.
10 years
Check Price
4. AlenBreathe Classic
12 Months
1,100 Sq. Ft.
Check Price
5. Dyson Pure Cool TP04
12 Months
Large Room
2 years
Check Price

Testing Environment

To get to know a little more about the product, we took the product for a rigorous testing phase for 60 days which was divided into two cycles. The first 30-day cycle was the intermittent testing phase where we alternated the days of use and the next 30-day cycle was an extensive blast testing with no breaks. We are really impressed with the Coway AIRMEGA 400s Air purifier especially how it pulled out in terms of performance in the second leg of the testing. 

When evaluating air purifiers, we looked closely at the published airflow rates vs sound level for each fan speed. Our goal for this unit was to have constant air purification with noise levels that would not be too obtrusive with the day to day living. For air purification to be effective there must be an adequate number of air changes per hour (ACH) at any desired air speed. Based on our research, the recommended ACH is about 4 to 6 air changes per hour range for effective particle reduction. That is the exact output target that we achieved with the Coway AIRMEGA 400S.

You will be amazed to find the level of practicality that the Coway AIRMEGA 400S offers just like it amazed our testing team.

1. Price

The biggest concern when it comes to using a device that is based on cutting edge technology is basically the price point at which you can work with. The Coway AIRMEGA 400s is one of the most sophisticated air purifiers and has got the best price ranges with which you can work. The price starts at a very minimal price point of $530. When compared to the competition that is prevalent in the field, the price point starts at $650. Although the product is priced a bit higher than some competitors but Coway surely offers what is promised. The features that are available within the device is also something that you need to take into consideration and is definitely worth every buck spent for. 

2. Market Overview

The global air purifier market is majorly driven by the growing prevalence of airborne diseases, increasing the number of population levels in the areas, rising disposable income and growing health consciousness, and growing requirements for the adoption of air pollution control equipment in the emerging regions. This propels the market with tremendous growth and contributes to maximum lucrative profits in the coming years. 

Moreover, leading vendors and manufacturers of the global air purifier market have teamed up to focus on partnerships, collaborations for the promotion of the air purifier industry. Furthermore, the prominent companies of the industry are taking efforts in managing, and developing the products and operational processes. Along with Coway, there have been many more companies including RabbitAir, Levoit, Alenbreath & IQAir which have been a part of this idea to upscale the market into new heights.

According to the reports, Coway has considerably marked the major growth owing to the increasing sale, putting advanced technology into air purifiers, and unique presence in the overall regarding the product as compared to other market vendors. Coway is on the verge of rapid growth in the global air purifier market in the coming years. 

Coway has expanded its business in all possible regions, providing its products across the globe. They have been pulling out their efforts in developing their products and making it more refined along with planning powerful strategies towards marketing and promoting their products across the globe. Thus this leads Coway to witness tremendous growth with maximum popularity in the near future. 

3. Design and Size 

Coway 400S Air Purifier Design and Size

Coway AIRMEGA 400S air purifier can be available in mostly white along with overall harmony and elegance, suitable for all types of architecture. 

  1. Coway AIRMEGA 400S is to provide the coverage specifically for large room sizes up to 1,560 sq.ft. and also cleans for every two times in an hour. 
  2. Coway’s AIRMEGA Max2 filter has the best combination of True HEPA filter and Activated Carbon filter. These filters are highly effective in refining the air and provide fresh airflow all over the place. This filter helps to detect over 99.97% of airborne particles till the range of starting from the range of 0.3 microns. It also reduces more than 99 percent of evaporative compounds and reduces fumes such as NH3 and CH3CHO. It also includes washable and permanent pre-filter to catch dust particles.
  3. As this device is automated, with the use of real-time, Coway AIRMEGA pollution sensor interacts with indoor air quality. The device also has a bright coloured LED ring and notifies you of the cleanliness or dust of your indoor air. 
  4. Coway AIRMEGA includes five fan modes such as Sleep, Low, Smart, Medium, and High. The noise of this device is minimum and the max noise reaches 43.2 db.

4. Filters

Coway 400S Air Purifier Filter

Coway AIRMEGA 400S holds the unique filters for the users as it can examine the performance of air purifiers to let the user notifies the percentage of air pollutants, airborne and other types of air which can result in harm. It is very important to know the types of filters and their features before use. It is very difficult to take out the air from the home which is air polluted and let users get into any airborne diseases or infections. 

There are a few innovative filters of Coway AIRMEGA 400S Air Purifier. Let’s learn about the types of filters which can help users of Coway feel surprised with the purified air. 

  1. Pre-Filter: This is a washable pre-filter that operates to capture large objects of contaminants. As every machine or a device needs maintenance, make sure to dry the pre-filter in the shade before reinstalling it for further use.
  2. Max2 Filter: This filter helps to detect over 99.97% of airborne particles until the range of starting from the range of 0.3 microns. It also reduces more than 99 percent of evaporative compounds and reduces fumes such as NH3 and CH3CHO. It also includes washable and permanent pre-filter to catch dust particles.

In case of complete usage of filter, you need to replace the filter with a brand new one. If you’re looking for Air purifiers with permanent or washable filters, you can check our other review of Air purifiers with washable filter.

5. Room Coverage

Coway 400S Room Coverage

It is important to get aware of the room coverage before giving an attempt to purchase Coway AIRMEGA 400S. Room coverage is such a thing that completely depended on the size of the room or house. So, when you operate the coverage should be easily accessible and the user not need to face any difficulties. The Coway AIRMEGA 400S has an effective coverage range of purifying around 1,560 sq.ft. This coverage is sufficient enough for the complete house to purifier the air and remove air pollutants and harmful air particles.

The CADR rate of the Coway AIRMEGA air purifier is on the top-notch range with nearly an efficiency of 99.96%. We don’t consider CADR of an Air purifier while providing our review as it can be altered very easily. We have even written an article on why CADR rating is an old term and you must not trust it.

6. Unique Features of Coway 400S

Coway AirMega 400S Air Purifier features

1. Enable Automatic Night Mode 

This could be one of the important reasons for buying Coway AIRMEGA 400S air purifier, as it offers the feature of enabling automatic night mode. We usually need the light sensor that would turn on the night mode and switch off the lights of the purifier. This feature can be seen only in 400 and 400S models of Coway. 

2. Air Quality Recording Resolution

Coway AIRMEGA 400S makes it possible to record the air quality of your room. This feature records the air quality of the room and notifies users on their application with the charts and figures. Moreover, the air quality is recorded routinely and it shows the small variation in the quality. It maintains the record of months, weeks, and a day to closely keep an eye on the quality of air. This feature is really important to measure the quality of the room.  

3. Scheduling

The prime reason to prefer Coway AIRMEGA 400S is the Scheduling feature. If you are creating a schedule, this feature can control the device when you are away from home. This feature enables the user to set a schedule according to the user’s comfort. The user can set the schedule in terms of Night, Auto, Low, Medium, and High. Moreover, the user can also set the time and day. The user can mark multiple schedules for every different day of the week.

Because of the automatic night mode feature, the device will turn on the night mode from 11 PM to 8 AM. During this particular time, the schedule will stop working. For this, the user should have to manually create a schedule of 24/7. Else, the schedule which you have set will automatically shut down. The experts recommend keeping the device in the night mode so that it won’t disturb you and set the night mode over and over again. It will regularly switch on the night mode automatically when the lights are turned off. 

Why Choose Coway 400S Air Purifier

1. Noise Level

We are mostly concerned with the sound level, but the reason to buy this product is it operates silently. As compared to the other products, this Coway AIRMEGA 400S air purifier produces around 22~52 dB (Just so you know, a normal conversation is at around 60dB & Whisper at around 30dB). Even on the low or high or in the night mode it operates with no noise and produces a good amount of airflow. Moreover, the user can also set the sound level manually from the application. 

2. Effective Filters

Coway AIRMEGA 400S has two high-quality filters and holds the ability to provide maximum fresh airflow. From the two filters, pre-filter is highly recommended by the experts as it reduces the dust rate and filters the good amount of dust. This filter is made of fine fabric mesh that is vacuumed on a weekly basis. Moreover, pre-filter is an extension for life and helps maintain high airflow through it. 

3. Effective Quality Airflow

Air purifiers protect our health and increase our immune power. Coway AIRMEGA 400S is the device that is closely designed with an intention to produce fresh and filter the maximum amount of dust as possible. The device is handy as the user can operate it from a smartphone with the help of an application. Due to the advanced activated carbon filter, the device can provide fresh airflow throughout the day. 

4. Powerful Performance

Coway Air Purifier 400S Compared with other

In terms of performance, Coway AIRMEGA 400S has the best performance rate from the other competitors. Coway AIRMEGA offers a performance rate of 99.95 percent along with purifying air every twice per hour. This helps the user to get constant fresh airflow. 

The Coway Airmega 400S performs a lot better than other HEPA & HEPA type Air purifiers because of its superior filter and area coverage. If you would use the Air purifier in small space, it would perform even better compared to its competitors like Levoit, Honeywell & BlueAir.

Customer Reviews for Coway AIRMEGA 400S Air Purifier

The biggest thing that moves a company’s products is the way the customers perceive about the product. There are a ton of developments in the sales of Coway AIRMEGA 400S mainly due to the service and the quality in performance index of the machine.

Most of the customers reviewed that the overall performance of the machine was so good that it was worth the investment for a second one if bigger households. There are also reports where there have been significant developments in terms of technology adaptiveness. There are also definite aspects in terms of the noise level as most of them found it quite relaxing and effective.

Well, the customer aspect of the Air purifier is definitely full filled with the amount of reviews that are prevalent on the seller’s websites. 

Coway’s Service reviews

Coway Air Purifier Service Center

Coway has an elite team to attend to repairs and maintenance especially in the US. It is evident that the definite arrangements that have been made with regard to the same is evidently seen in the developmental strategies that the company is implementing to make sure that the service aspect is maintained at the top notch level. 


The product is proudly winning the market as customers are believing the power of Coway AIRMEGA 400S air purifier. Though it is an expensive product, this product is worth buying. As compared to other products, Coway AIRMEGA 400S is the device that offers a number of features and smooth functionalities to make the airflow fresh and effective. After buying this product, the user does not need to worry about the health issues from the dust or any airborne disease. It filters the dust and takes out all the bacteria, pollen before pulling out the air at your home. You can still compare the Airmega with other Air purifiers like RabbitAir MinusA2, LEVOIT HV-H134 & AlenbreatheSmart Classic Air Purifier. However, if you’re looking for a medical-grade air purifier which would stop germs and bacteria, you can buy the IQAIR Air Purifier.

In terms of smart product, this Coway AIRMEGA 400S air purifier is an eco-friendly and energy-saving technology that operates with the sensor systems of air, humidity, odours, dust such as Inverter technology, intelligent mode automatically adjusts airflow rate, filter replace indicator lamp, air pollution warning lights, and sleep/night mode. This product is designed in a modern style with a rectangular shape and neutral colour. This product enables users with the number of features, smooth functionalities in the reasonable pricing. 

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *