What Are Air Filters Made of? Types of Air Filter Media
https://www.ge-tek.com/filter-media
Clean air is critical in environments ranging from hospitals to semiconductor fabs, and the key to achieving it lies in the filter media. More than just a screen, filter media are engineered materials designed to capture specific contaminants—whether particles (PM) like dust and bacteria, or airborne molecular contaminants (AMCs) such as gases and vapors. The choice of media determines a filter’s performance, efficiency, and service life.
In this guide, we’ll examine the main types of air filter media for both particulate and gas-phase control, outlining their properties, applications, and advantages so you can match the right material to your environment.
What Are Air Filters Made of?
Air filters are built from two main elements: the frame, which gives the filter its structure, and the filter media, which does the actual work of removing contaminants. Both parts matter, but their roles are very different—the frame ensures stability and prevents leaks, while the media determines what pollutants are captured and how well the filter performs.
The Frame
The frame provides the structure that holds the filter in place within an HVAC system. It is typically made of metal, plastic, or cardboard, depending on the application and durability required. A well-constructed frame ensures the filter maintains its shape under airflow pressure and prevents bypass leakage, where unfiltered air slips around the edges instead of through the media.
The Filter Media
The filter media is the heart of the system. This is the material responsible for actually capturing particles and gases as air passes through. Its composition determines the filter’s performance, efficiency, and lifespan. Different media types are designed to target different contaminants: some specialize in trapping dust, pollen, and bacteria, while others are engineered to adsorb gases, odors, or chemical vapors.
Because the filter media plays such a central role, the following sections will explore the main types used for particulate filtration and gas-phase filtration, along with their unique properties and applications.
Air Filter Media for Particulate Filtration
Particulate filtration focuses on removing dust, pollen, fine particles, and even submicron contaminants that can compromise sensitive environments or equipment. The effectiveness of this stage depends largely on the filter media, which must be matched to both the application and the operating conditions. Several media types are widely used, each offering unique performance advantages.
Fiberglass (Micro-glass)
Fiberglass is the classic choice for high-performance applications such as HEPA and ULPA filters. Its fine fibers are capable of capturing extremely small particles, including those in the submicron range. In addition to efficiency, fiberglass offers strong resistance to heat and chemicals, making it suitable for cleanrooms, healthcare facilities, and precision manufacturing environments where consistent, reliable performance is essential.
PTFE (Polytetrafluoroethylene)
PTFE, often known by its trade name Teflon, is valued for being chemically inert and highly resistant to high temperatures. Its smooth, non-stick surface resists fouling and clogging, extending the service life of the filter. PTFE media is commonly used in harsh or corrosive environments and in processes where temperature fluctuations would quickly degrade other materials.
Polyester (PET)
Polyester is a durable and cost-effective option, making it one of the most common materials in commercial and industrial HVAC systems. It is typically found in pre-filters or mid-range MERV filters, where it provides reliable particulate control at an accessible price point. Polyester media is a practical choice for facilities seeking a balance between performance and operating cost.
Polypropylene (PP)
Polypropylene offers excellent chemical resistance and structural stability. It is often used in sediment and particulate pre-filtration, particularly where exposure to moisture or chemicals could limit the lifespan of other media. Also, it is used in liquid filtration and as a composite layer with other media to tune strength and efficiency.
To sum up, particulate filter media are not interchangeable—each is tailored to specific needs. Fiberglass delivers the ultra-fine capture required in cleanrooms and healthcare. PTFE thrives in corrosive, high-temperature conditions where longevity is critical. Polyester strikes a cost-performance balance for everyday HVAC systems, while polypropylene offers chemical stability and versatility in pre-filtration or composites. The insight is clear: effective particulate filtration depends less on a universal “best” material and more on matching the media to the contaminants, environment, and performance goals of the application.
Air Filter Media for AMC Filtration
Airborne molecular contaminants (AMCs) cannot be captured with standard particle filters. To remove these gases and vapors, HVAC and process systems rely on specialized molecular filtration media. These materials use physical adsorption, chemical adsorption, and chemisorption to target specific contaminants, ensuring clean and stable air quality in demanding environments.
Premium Activated Carbon
Activated carbon remains the most versatile medium for gas-phase filtration. With a vast internal surface area, it removes contaminants primarily through physical adsorption. It is effective against a wide range of volatile organic compounds (VOCs), including formaldehyde, aldehydes, and sulfur-based gases(sulfur dioxide (SO₂), hydrogen sulfide (H₂S)). Activated carbon also reduces odors such as smoke, food smells, and paint fumes. Thanks to this broad effectiveness, activated carbon is used across industries—from semiconductor cleanrooms and electronics assembly to food processing plants and general HVAC systems.
Impregnated Activated Carbon
For more challenging contaminants, carbon can be impregnated with chemical agents to boost reactivity. These enhanced filters capture and remove acidic gases such as sulfuric acid (H₂SO₄), sulfurous acid (H₂SO₃), sulfur dioxide (SO₂), chlorine (Cl₂), hydrogen chloride (HCl), hydrogen sulfide (H₂S), nitrous acid (HNO₂), hydrofluoric acid (HF), and hydrobromic acid (HBr). Removal occurs through chemical adsorption and reaction, which transforms harmful gases into stable, non-volatile compounds. This makes impregnated carbon indispensable in battery manufacturing, chemical processing plants, wastewater treatment facilities, and laboratories where corrosive gases are common.
Ion Exchange Resin
Ion exchange resins provide targeted control of alkaline gases(BASEs). Compounds such as ammonia (NH₃), amines, N-methyl-2-pyrrolidone (NMP), and hexamethyldisilazane (HMDS) can corrode surfaces, contaminate products, or interfere with sensitive chemical reactions. Using chemisorption, ion exchange resins form strong bonds with these molecules, preventing them from circulating in the air. Because alkaline gases are common in semiconductor lithography and etching, pharmaceutical production, and electronic chemical manufacturing, ion exchange resins are essential for protecting products, ensuring process stability, and maintaining compliance.
Overall, airborne molecular contaminants (AMCs) require specialized media that go beyond particle filters. Activated carbon is the most versatile option, physically adsorbing VOCs, aldehydes, sulfur gases, and odors across HVAC, cleanroom, and food applications. For environments with corrosive acidic gases, impregnated carbon uses chemical adsorption and reaction to remove compounds like SO₂, HCl, and HF. Meanwhile, ion exchange resins target alkaline gases(BASEs) such as ammonia, amines, and NMP, which are common in semiconductor and pharmaceutical processes. Effective AMC control depends on choosing the right medium for the contaminants present.
Beyond Filtration: Partnering with Getek for Complete Air Quality Control
At Getek, filtration is more than a component—it’s an integrated strategy for protecting people, processes, and equipment. Our portfolio spans particulate and molecular air filters, combining high-efficiency, high-capacity, and low-pressure-drop engineered design to address a full spectrum of contaminants with precision.
What sets Getek apart is not only the quality of our products but also the engineering expertise and customization support we provide. From analyzing contaminant profiles to modeling filter performance under real operating conditions, our team works with you to design solutions that align with your facility’s goals for reliability, compliance, and cost efficiency.
Whether you operate a semiconductor fab, pharmaceutical cleanroom, food production facility, or commercial HVAC system, Getek delivers solutions that adapt to your unique challenges. With our guidance, you can be confident in achieving consistent air purity, reduced maintenance downtime, and long-term performance.
Explore Getek’s filter technologies and connect with us to design the right solution for your environment.