Air filters capable of filtering pollen, dust mites and other forms of particulate matter out of your build's air columns are always a useful addition to a building, but they are particularly prized by people who can suffer from allergic reactions when they come into contact with these unwanted particles. Whether you're a homeowner seeking to keep your family from inhaling dust and detritus, or a business owner trying to reduce instances of hayfever-related illnesses in your work force, air filters can help.

However, not every air filtration system is created equal, and some filter models are far more effective at catching allergenic materials than others. To ensure the filter you buy provides the best possible protection against allergic reactions, make sure your chosen filter system has the following vital attributes:

HEPA filters

Most low-end air filtration systems use physical filters made from finely woven fibreglass or other materials; some use an electromagnetic charge to attract dust particles and other airborne pollutants for easy collection. Neither of these filter types is truly effective at catching allergenic particles, as these particles are often microscopically small and can find their way through these filtration types.

To provide effective protection against allergic reactions, you should choose a filtration system fitted with High Energy Particle Arrestance (HEPA) filters. These filters are made from randomly-arranged screens of incredibly fine and densely-woven fibres, and are capable of catching airborne particles less than a micron in diameter, making them ideal for filtering all but the most unusual and exotic of allergy-causing particles out of your air supply. Some HEPA filters even use additional filtration systems, such as electromagnetic plates or ozone generators, to maximise the protection they offer.

Sufficient flow rates

Air filters can only work as quickly as the fans that push air through their filtration systems, and you should make sure to invest in an air filter with sufficient air flow rates to ensure that rooms are constantly get free of allergens. As a general rule, this entails choosing a filter that can recirculate all the air within a room within the space of a few minutes -- if you are purchasing filtration systems for expansive rooms (such as warehousing facilities) multiple filters may be necessary. Air filtration suppliers will be able to help you calculate how high a flow rate you need for a specific room.

Low noise levels

Some inexpensive air filters may provide adequate protection against allergenic particles, but this effectiveness often comes at the price of a noisy and distracting air filter. A noise filtration system can be equally distracting in work or home environments, so you should try to find a filtration system that marries effective filtering with low levels of operating noise. 

This generally means finding a system with a heavily insulated housing to prevent excessive sound from escaping. Choosing a filter with a less powerful air exchange system is not recommended, as this can reduce the effectiveness of your filter and entail more regular filter changes. You may also find that building air filtration systems into existing ventilation and air conditioning ducts is a good way to reduce ambient noise, and many air filter suppliers offer models that can easily be integrated into existing filtration systems.