Air filters capture airborne contaminants and help improve your facility’s IAQ. These contaminants come in the form of particles, gases, and vapors. The portion of airborne pollutants captured and the size of those particles determines the filter’s minimum efficiency reporting value (MERV) rating. Poor air quality creates unwanted results like employee absenteeism and early product spoilage. It can even threaten food safety.

Odors

Air filtration can also trap odors in the air, which can be an issue in homes with smokers or other foul-smelling activities. Air cleaners with activated carbon filters are best for this task.

The air filter most people use in their homes is a basic, matted fiberglass model designed to protect the furnace from large dust particles. While these filters keep surfaces in the home cleaner, they don’t capture many allergens.

For this reason, if you want to buy a filter, choose one that can remove a broader range of pollutants from the air. It may include a HEPA filter, which is especially effective for catching microscopic pollutants that irritate the lungs and can trigger allergies or asthma. Other filters, like carbon and foam, can also detect odors in the air.

Gases

Air filtration is designed to separate dispersed contaminants in the form of particles from the airflow. Filter performance depends on its ability to capture a specific set of pollutants in the desired quantity while presenting the lowest resistance to the flow.

The effectiveness of a filter in capturing a given particle size is determined by the type and construction of its medium. The most commonly used filtration technique is surface straining, a sieving process. Particles more significant than the pore size of the filter media are expected to be deposited on the filter surface, where they should remain trapped by the dust cake formed.

This method effectively captures large particles like pollen, pet dander, and dust mites. However, it does not catch gases or vapors such as VOCs (volatile organic compounds) that may accumulate from adhesives and paints.

Bacteria

Air filters may contain fiberglass, cellulose, or woven metal filaments. An air filter of any size, whether that be a 30x36x1 or 16x22x1 air filter, is generally designed to trap the smallest particulates with a minimum efficiency reporting value, or MERV rating. A higher MERV rating indicates greater filter efficiency.

Dust can be hazardous to health, whether flammable (as in wood dust) or toxic (from specific materials). It can cause lung scarring, asthma, and allergies. It can also spread bacteria, viruses, and parasites that cause gastrointestinal or urinary infections.

This review will explore studies using portable air filters in indoor settings such as care homes, schools, and offices/workplaces to investigate either their association with the incidence of respiratory infections or their effectiveness in capturing aerosolized bacteria and viruses. It includes both randomized controlled trials and observational studies.

Particles

Airborne particles are a significant form of air pollution. They include dust, smog, particulate matter from burning fossil fuels and organic decaying material, and many other artificial or natural compounds that can cause severe pulmonary diseases such as silicosis and pneumoconiosis.

Particles smaller than the mesh openings in filter fibers are intercepted by inertial impingement or diffusion. The blocked particle size can be controlled by varying the airflow velocity through the filter medium to improve efficiency.

Air filters can capture microscopic pollutants such as viruses, bacteria, allergens, mold spores, and other bioaerosols. The ability of a filter to remove these smaller contaminants is often indicated by the MERV (minimum efficiency reporting value) rating on the label. It is an industry-standard that measures the percentage of particles captured by the filter media in a given test.

Mold

Many fungi, including black mold, release mycotoxins. These toxic chemicals can cause many symptoms in humans and animals. The most common symptoms include skin irritation, asthma, and sinus inflammation.

Activated carbon is one of the most helpful cleaning materials available. It is highly porous and able to trap a large number of contaminants. It is an ideal choice for removing odors and other volatile organic compounds. VOCs can come from paints and lacquers, wood products, cleaning supplies, building materials and furnishings, office equipment like copiers and printers, and cooking.

Using an air filter is the best way to reduce VOCs. However, it is essential to remember that an air filter will not eliminate an existing problem with mold growth. Visible mold must be remediated and removed from surfaces before an air purifier can help.