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 A person using a pre-filter on a Coway air purifier.

What Are Pre-filters and Why Are They Essential to Air Purification?

Clean air is essential for a healthy and comfortable living environment. With the increasing levels of pollution and airborne particles, the need for effective air purification has become more significant than ever. Air purifiers play a crucial role in removing contaminants from the air, and pre-filters are an integral component of these systems. 

In this article, we will explore what pre-filters are and why they are essential to air purification.

A person cleaning a prefilter for a Coway air purifier.

What Are Pre-filters?

Pre-filters are the initial line of defense in an air purification system. They are the first stage of filtration, designed to capture larger particles and prevent them from entering the main filtration system. These particles can include dust, hair, pet dander, pollen, and other visible debris commonly found in indoor environments.

Composition and Function

Pre-filters are typically made from a variety of materials, such as foam, mesh, or fiberglass. The choice of material depends on the specific requirements of the air purifier and the types of particles the pre-filter needs to capture. Regardless of the material, the primary function of a pre-filter is to trap larger particles before they reach the more advanced filters in the purification system.

Washing a prefilter to maintain it over time.

Importance of Pre-Filters in Air Purification

Pre-filters play a pivotal role in the overall efficiency and effectiveness of air purification systems. These unsung heroes are designed to capture larger particles such as dust, pet dander, and hair, serving as the first line of defense before the air passes through more advanced filtration stages. 

Understanding the importance of pre-filters unveils their critical role in enhancing the longevity of main filters, improving air quality, and ultimately contributing to a more comfortable and breathable living space.

Extended Lifespan of Main Filters

By capturing larger particles, pre-filters prevent them from clogging the main filters. This helps prolong the lifespan and effectiveness of the HEPA (High-Efficiency Particulate Air) or activated carbon filters, which are responsible for trapping smaller particles and removing odors.

Improved Air Quality

Pre-filters contribute significantly to the overall air quality by removing visible particles. While they may not be as effective in capturing microscopic particles, their role in reducing the concentration of larger contaminants is crucial for creating a cleaner and healthier indoor environment.

Enhanced Energy Efficiency

Air purifiers with pre-filters operate more efficiently, as the main filters experience less strain. This leads to energy savings and a more cost-effective use of the purification system over time.

Reduced Maintenance Costs

Regularly vacuuming or rinsing pre-filters is a cost-effective maintenance practice. It is more economical to replace a pre-filter than a high-efficiency filter, and doing so ensures that the entire air purification system continues to function optimally.

Customization for Specific Environments

Pre-filters can be designed to target specific types of contaminants based on the environment. For example, in homes with pets, a pre-filter with enhanced pet dander capture capabilities can be used.

All About Coway Pre-Filters

Dive into the core of air purification efficiency with Coway Airmega's Pre-Filter. As a vital component of Coway's advanced filtration system, the Pre-Filter plays a crucial role in capturing larger particles like dust and pet hair, acting as the first line of defense. These washable and easy-to-dry pre-filters not only ensure cleaner air but also prolong the life of subsequent filters, making maintenance hassle-free. Explore the science behind Coway's Pre-Filter and discover how it contributes to creating a healthier and fresher indoor environment.

Invest in Your Health with Coway

Pre-filters are essential components of air purification systems, providing a crucial first line of defense against larger particles. Their role in extending the lifespan of main filters, improving air quality, enhancing energy efficiency, and reducing maintenance costs makes them indispensable for maintaining a healthy indoor environment. When choosing an air purifier, understanding the importance of pre-filters can help consumers make informed decisions to ensure effective and long-lasting air purification.

Shop Cowaymega for our range of optimized air filtration systems.


1Coway air purifiers have been proven to trap dust, pollen, dander, viruses and bacteria in the air based on KCL (Korea Conformity Laboratories) testing.They have been tested in a 30㎥ size chamber according to the Korea Air Cleaning Association standard (SPS-KACA 002-132:2022 Modified) to measure the 0.01㎛ size of particle removal rate. It was tested on maximum airflow speed in normal room temperature and humidity conditions. The performance may vary in the actual living environment of customers.
→ Tested with Airmega Aim, 100, 150, 160, AP-1216L, AP-1512HH, AP-1512HHS, 200M, Icon, IconS, 230, 240, 250, 250 Art, 250S, 300, 300S, 400, 400S, ProX

299.97% of viruses, bacteria, fungi and pollen were verified to be removed from the air for Coway air purifiers which have Green True HEPA™ filter applied based on the Japan Food Research Laboratories(JFRL) testing according to JEM 1467 standard.
→ Tested with Coway Airmega AP-1512HH, AP-1512HHS, 250, 250 Art, 250S, 300, 300S, 400, 400S
→ All tested by JFRL and received above result within below time.

All tested by JFRL and received above result within below time.

- Virus: Tested with Escherichia coli phage ΦX174 NBRC 103405, 60 minutes
- Bacteria: Tested with Staphylococcus epidermidis NBRC 12993, 60 minutes
- Fungi/Mold: Tested with Penicillium citrinum NBRC 6352, 60 minutes
- Pollen: Tested with Cedar Pollen extract, 60 minutes

3Aerosol test conducted in a Biosafety level 3 laboratory with two Coway air purifier models, Coway Airmega 250 and 400 for removal of SARS-CoV-2 Aerosol by US based MRI Global, a not-for-profit laboratory and partner of US Department of Defense. The test was conducted in a 13.1ft3 chamber. Virus was aerosolized for 15 minutes and the product was turned on high for 2 minutes. Result showed each product effectively removed over 99.98% of the SARS-CoV-2 in 2 minutes. This is a result from a laboratory experiment condition and result may vary in different conditions. This result does not imply it kills SARS-CoV-2 or prevents the transmission of Covid-19. Coway Airmega 250S and 400S are identical to the tested models and has equal performance with an additional mobile connectivity function.

4The concentration of ammonia, acetaldehyde and acetic acid were proven to be removed within 30 minutes by FCG Research Institute, Inc. Human Life Science Lab. It is not a demonstration result in the actual use space. Not all odors and gases may be supported. → Tested with Coway Airmega 150, 160, AP-1512HH, AP-1512HHS, 400, 400S

5The coverage area of the air purifier is based on an area where the air cleaner can make two air changes per hour (ACPH). An air change per hour translates to how many times an air purifier can clean an area, assuming the height of a ceiling to be 8 ft, in one hour. Therefore ** means two air changes per hour means that the cleaner can clean the area once every 30 minutes and * means air changes per hour means that the air purifier can clean the area once every 60 minutes.

10Terms and conditions apply. Discounts, including promotions, coupons, bundle discount and subscription discount, cannot be stacked on top of other coupons. During promotional periods, discount codes will not be able to be applied to orders. Promo codes may apply to products only—filters, accessories, and new products within 3 months of the release date are not included.