While air purifiers can help with many respiratory issues, it is just part of the cure. The EPA estimates that up to 24 million Americans -- primarily over the age of 45 -- suffer from chronic obstructive pulmonary disease (COPD) and many more are diagnosed with similar symptoms caused by emphysema. Both conditions restrict airway passages and are aggravated by airborne contaminants, especially cigarette smoke and synthetic surfaces that create volatile organic compounds (VOCs). Most residential air purifications units remove a portion of these irritants from the immediate environment, but their effectiveness is limited and determined by the features included in each model.
Both emphysema and chronic bronchitis sufferers experience:
(image courtesy of Wikipedia Commons)
These symptoms are no doubt affected by air quality, and studies by the EPA in 1990 ranked indoor air quality as a "high-priority public health risk," especially for persons suffering from such serious respiratory conditions. Although proper air purification may help alleviate many irritants and possibly even prevent the development of these ailments, it is by no means a cure and will only help lessen the symptoms once the patient's airways have been compromised. Consequently, just having a top-of-the-line air purification system will not replace medically prescribed treatments such as inhalers, antibiotics and steroids that may be recommended to keep the disease from escalating.
Most doctors do, however, highly recommend air purification equipment as part of a restorative regime for patients who have COPD or emphysema, and physicians can recommend the right type of system on a case-by-case basis. Traditional HEPA filters only remove particles down to .03 microns, and bacteria can be as small as .01 microns. so these are not adequate for combating the types of infection for which that COPD and emphysema suffers are especially susceptible. To effectively remove the majority of the irritants, patients with respiratory illness need to select a multi-stage filtration system.
The National Air Filtration Association recommends that to obtain maximum effectiveness, there should be an advanced filter and UV light system hooked up to the HVAC unit in the residence so that the large amount of the contaminants can be removed before entering the home in the first place. Standard air filters for these units are limited by the small horsepower output of the fan motor, so a self-contained filteration system with its own fan will be more effective. However, since a high rate of air flow is necessary for HVAC systems, HVAC filters typically cannot incorporate HEPA filters due to air flow restriction. HEPA-type filters are usually sufficient to filter most of the larger particles.
Medical professionals always point out that no air purification system can be expected to eliminate all airborne contaminants, especially those stirred up by walking across a carpet or laying on a pillow since they must enter the airstream of the unit before they are filtered out. They strongly recommend that steps should be taken to remove items that generate dust and eliminate any mold or mildew at the source. Frequent vacuuming and dusting of surfaces is highly recommended.
EPA - Guidelines for healthy homes: http://www.epa.gov/region1/healthyhomes/iaq.html
Mayo Clinic - COPD Definition: http://www.mayoclinic.com/health/copd/DS00916
WebMD - Avoiding Triggers for COPD: http://www.webmd.com/lung/copd/avoiding-triggers-for-copd
EPA - Study on Cleaning Residential Air: http://www.epa.gov/iaq/pubs/residair.html#Will%20Air%20Cleaning%20Reduce%20Health%20Effects
National Air Filtration Association - Whole House Filtration: http://www.nafahq.org/LibaryFiles/Articles/Article003.htm
WebMD - You Need and Air Filter: http://www.webmd.com/asthma/guide/do-you-need-an-air-filter