Air Filtration Terminology

Activated carbon is a high-purity form of carbon which can be used in filters. It is used to remove particles, such as pollutants and odours, from the air by absorbing them.

This is the process of treating or altering air in an indoor space to maintain a comfortable and controlled environment. Adjustments include cooling, heating, ventilation, humidification, dehumidification and air purification.

This is the measure of how frequently the air in an indoor space is replaced with fresh air or outside air. The air exchange rate is expressed as either air changes per hour (ACH) or cubic feet per minute (cfm).

An air filter is a device that removes particles, contaminants, and pollutants from the air to improve indoor air quality. They are commonly used in heating, ventilation and air conditioning systems as well as air purifiers.

This is a component of heating, ventilation and air conditioning systems. Air handling units typically consist of a fan, heating and cooling elements, filters, and dampers, to circulate air throughout a building.

Air pressure is the force of air as it moves through a filtration system or ductwork. In air filtration, it is used to indicate how freely air can pass through filters and equipment, with higher pressure showing increased resistance.

An air purifier is a device that cleans the air by drawing it through filters or other purification technologies. It helps reduce airborne contaminants such as dust, allergens, odours and pollutants before releasing cleaner air back into the space.

Air quality refers to the condition of the air in terms of the presence of pollutants, contaminants and other substances that may affect health and the environment.

Airborne particles are tiny pieces of matter, either solid or liquid, that are suspended in the air. These can include dust, pollen, smoke and industrial contaminants, and are commonly removed using air filtration systems to improve air quality.

An allergen is a substance that can cause an allergic reaction when inhaled or contacted. Common airborne allergens include pollen, dust mite particles and mould spores, which can be reduced through effective air filtration.

Bacteria are single celled microorganisms. They range from beneficial and essential to life, to intensely harmful and even lethal.

A bag filter is a type of filtration system that features a bag-shaped media to filter particulates from the air passing through the system.

This is a filtration system that uses activated carbon to remove pollutants, contaminants and other substances from the air.

A carbon panel filter is another name for a carbon filter, denoting a panel-style filter with activated carbon as the filter media.

A cartridge is a replaceable filter element installed within a filtration system. As air passes through, the cartridge traps contaminants and is removed and replaced once it reaches the end of its working life.

C02 is the abbreviation of carbon dioxide, a gas that is composed of two oxygen atoms bonded to a carbon atom.

This is the amount of dust or particulate matter an air filter can retain before needing to undergo maintenance, cleaning, or replacement.

Energy efficiency refers to how effectively an air filtration system operates while using minimal energy. Efficient systems reduce airflow resistance, helping fans and HVAC equipment run more economically.

EN779 is the European standard for classifying particulate air filters based on their filtration efficiency and dust holding capacity. EN779 is commonly used in HVAC and air filtration applications.

An extractor fan is a mechanical fan designed to remove stale, contaminated or humid air from a space. It draws air out of an area and either vents it externally or directs it into a filtration system.

This is the ability of the filter to remove particles from the air. The efficiency of the filter is calculated by comparing the amount of the particles upstream and downstream of the device or by the percentage of particles retained by the filter compared to the total number passing through.

The filter frame composes the outside of a filter, holding and stabilising the filter media on a filter. Not all filters feature frames; panel filters, bag filters, and V-cell filters are examples of filters that feature frames.

Filters are graded based on filtration efficiency and the particle size that the filter can capture. This is determined by industry standards, which break down efficiency into several classifications.

Filter housing is the casing that holds air filters securely in place. It ensures air flows correctly through the filter media while protecting the filter and maintaining system performance.

The filter lifespan refers to how long a filter remains effective before it requires replacement, based on its ability to maintain performance and efficiency in capturing particles.

Filter mats are manufactured from a filtration media and are suitable for applications where a frame is not required, including HVAC and spray booths, to remove pollutants from the air.

This is the material or substance used for filtration in a filter. The media traps and removes particles and other contaminants from the air. Different media material is available depending on the application and particulate size and type.

Final pressure drop is the maximum level of airflow resistance a filter reaches before it needs replacing. As contaminants build up in the filter, resistance increases and airflow performance reduces.

A grease filter is specifically designed to trap grease and smoke particles. This is typically used in commercial kitchens, where grease and smoke build up during cooking and become a potential fire hazard.

HEPA stands for High Efficiency Particulate Air filter – referring to the efficiency of the filter. HEPAs are designed to capture particles down to 0.3 microns with an efficiency up to 99.97%.

Holding capacity is the amount of dust or particulate matter a filter can retain before reaching its final pressure drop. Filters with a higher holding capacity generally have a longer service life.

HVAC is an acronym for Heating, Ventilation and Air Conditioning, a system that adjusts the air in a room depending on temperature, humidity, and purity.

HVAC filters are used within heating, ventilation and air conditioning systems to remove airborne particles from circulated air. They help protect equipment and maintain good indoor air quality.

Indoor air quality (IAQ) is the condition of the air in a specified place, focussing on the presence of pollutants, contaminants, and comfort levels of those occupying the indoor space.

This is an international standard for testing and classifying air filters based on their efficiency in capturing particulate matter of different sizes. ISO 16890 has replaced the previous standard, EN779.

MERV stands for Minimum Efficiency Reporting Value. It is a rating system used to measure how effectively a filter captures airborne particles, with higher ratings indicating finer filtration.

A microfibre is an extremely fine synthetic fibre, known for its ability to trap and hold dust, dirt and liquids.

Flat, rectangular filters consisting of pleated or non-pleated media enclosed within a frame, which can be made from cardboard, plastic or metal. Panel filters can be used within HVAC systems.

This refers to the folds made in paper-based filter media. The pleats increase surface area, improving the ability of the filter to capture particulates while maintaining a compact size.

A particle is a small piece of matter, either a solid or a liquid, that can vary in size, shape, and composition. Dust, pollen, and smoke are all types of particles.

Another type of filter, the pleated filter utilises pleated (folded) filter media encompassed within a frame. Also known as a pleated panel filter, the increased surface area of the pleated media traps particulates.

Pollution refers to harmful substances present in the air that can affect health, processes or equipment. This can include dust, fumes, gases and other contaminants that air filtration systems aim to control.

Polyester (PET) is a synthetic polymer made from plastic, commonly used in textiles, packaging and industrial applications for clothing, upholstery and other products. Polyester is known for its durability and quick-drying properties.

Pocket filters are a filter type known for its filter media which extends out from the frame, providing an increased surface area for an improved holding capacity.

A pre-filter is the first stage of filtration in a multi-stage system. It captures larger particles before air reaches the main filter, helping to extend the life of the primary filter.

This is a type of filter that uses a bag-shaped media structured by a rigid metal or plastic frame. Rigid bag filters are used in commercial and industrial HVAC systems for high dust-holding capacity and a low pressure drop.

A spray booth filter is commonly used in industrial spray booth applications to capture overspray before it enters extraction systems. It consists of a filter mat in a specified filter media.

This is a disinfection method to kill or inactivate microorganisms, such as bacteria, viruses and other pathogens. UGVI uses ultraviolet light to do this, and can be used in air, water, and surface disinfection applications.

V cell is another name for a rigid bag filter, a type of filter media that is encompassed by a rigid frame to structure it as an open bag shape.

The process of exchanging indoor air with outdoor or fresh, filtered air to improve air quality.

Volatile Organic Compounds are organic chemicals that evaporate at room temperature, releasing gases in the air that can be dangerous or problematic to the environment, air quality, and human health.