Do Air Purifiers Help With Allergies?
Since allergies are triggered by airborne particles, it is natural to assume that air purification devices will help alleviate the symptoms since they constantly filter contaminants from the immediate environment. While this concept is true to a degree, it is necessary to do some research to determine which product is best suited for the kind of allergens that cause the irritation, because not all units produce the same results.
Sources of Indoor Allergy Triggers & Effectiveness of Air Purifiers
According to the Asthma and Allergy Foundation of America (AAFA), a non-profit patient advocacy group, the main indoor triggers for allergies are:
- Mold and mildew
- Hair and dander from pets
- Tobacco smoke
- Insect infestation – especially cockroaches & dust mites
- Volatile Organic Compounds (VOCs) emitted by synthetic carpets, fresh paint, plastic and glues
If these particles stay suspended in the air, some air purifiers can filter them. However, pet dander and dust mite feces in particular are heavier particles that often settle quickly and do not stay suspended in the air for long. Most air purifiers are very effective at removing tobacco smoke but the best recommendation is not to allow smoking in the house at all.
Strategies For Reducing Indoor Allergy Triggers In Addition to an Air Purifier
The United States Environmental Protection Agency (EPA) does recommend air purification products as part of the solution to tackling indoor air pollution that causes allergies, but considers it just part of a overall strategy that includes:
- Adequate ventilation
- Removal of on-going pollution sources like pets, smoke and mildew
- Replacement of materials that emit VOCs
- Proper insulation to prevent infiltration of allergens
- Remove carpets wherever possible, they are a significant source of trapped allergens
- Air purification devices either for single rooms or whole house systems
Of course, many allergy suffers are affected seasonally by pollens and other environmental factors. In this case, the correct type of air purification device can prove very beneficial since these irritants are typically large particles that can easily be trapped by a filter.
Air Purifier Filter Technology
Air purification technology uses a number of different methods for air filtration, and it is recommended by the AAFA that you consult with your doctor to determine which type of system will eliminate the specific allergens that trigger your symptoms. AAFA cautions consumers about accepting the manufacturer’s claims and urge them to investigate the pros and cons of different methods fr themselves with their doctor’s guidence. The following air purification products are the most common for residential use:
- HEPA Filters – True HEPA filters will capture a minimum of 99.97 percent of the airborne particles that are up to 0.3 microns — which is sufficient for most irritatants — and must be replaced every 6 months to a year and are typcially effective for seasonal allergies. HEPA filters will not help filter particles that have already settled onto surfaces
- Electrostatic Filters – Electrical charges attract all allergens from the airstream and collect them on electrostatic plates which must be cleaned frequently to remain effective. May produce small amounts of ozone so these are rarely recommended.
- Hybrid Filters – Using barrier filters like HEPA and material such as activated carbon to filter gasses provides an effective combination to reduce some types of allergen triggers
- Ozone Generators – Although ozone generators may eliminate some particles from indoor air, they are not recommended because they exceed the acceptable levels for ozone, which can further complicate respiratory problems.
Even the most advanced residential air purifications systems cannot eliminate all airborne contaminants, especially ones released by contact with items such as pillows, rugs and furniture. The particles have to pass through the mechanism before they can be removed, and it can take even the best air purifier 15-20 minutes to clean the air in typical room depending on the fan speed of the unit.
For maximum protection, whole house air purification systems installed as part of the HVAC unit are highly recommended to filter larger particles combined with portable units with HEPA filtration to filter the smallest particles in rooms where allergy sufferers sleep.
Air Purifier Feature Considerations
Once you have determined the correct type of air purification system that works best for your particular allergies, you also need to consider the following factors before purchasing:
- Coverage area – helps you match an air purifier with room size
- Noise level – air purifiers have a large range of noise output depending on fan size and air flow rate
- Cost and ease of filter change – most air purifiers require annual (or sooner) filter changes
- Efficiency rating – how well an air purifier filters the air, rating systems vary. Try to find a purifier that filters the type of particles you are allergic to