Perhaps you or a family member suffers from seasonal allergies, and you've heard that an air cleaner can keep pollen out of the house. Or, you may want to reduce cooking and smoke odors at home or in the office. Every house with plants, pets or people is automatically polluted by these. Even if you don't have plants or pets, it is still polluted because you live there. According to the EPA, the air in most homes is at least two to four times more polluted than outside air.

Most of us spend up to 90 percent of our time indoors breathing polluted air and only 10 percent of the time breathing healthy, oxygen-rich outdoor air. The result is that many of us suffer from asthma, allergies and hypersensitivity. This has become more common in recent years, since America in general has become a sedentary, couch-potato society.

Your first line of defense is to replace indoor air by fresh, outside air on a regular basis. You can open doors and windows and add exhaust fans. You also should minimize sources of contamination inside your home by cleaning it regularly. Good housekeeping can help control dust and dust mite problems.

If natural ventilation and exhaust fans do not take care of the problem, you may need an air cleaner. You need to decide whether you have problems in a room or small space or if you have air quality problems throughout the house. When the problems are throughout the house, in-duct filters are an alternative. Otherwise, a portable cleaner may be a better choice.

How do you decide if you need an air cleaner? And if you do need one, which one is right for your situation? HEPA filtered air cleaners, air purifiers and vacuum cleaners are highly recommended for all allergy and asthma sufferers. Although sometimes expensive, they are worth it if it means your health will be better.

You chould get to the real sourch of what is causing the pollution in your house, then reducing that exposure or removing it. As an adjunct to effective source control and adequate ventilation, highly efficient air cleaners can be useful in further reducing levels of certain indoor air pollutants. More research on the health benefits of air cleaners is needed to provide complete evidence that would better address the circumstances of intended use.

The reality in most residences is that total elimination of a pollutant source is not always possible or practical. Individuals with severe allergy and asthma symptoms, whose symptoms are not alleviated by other source control and ventilation strategies, may want to try an effective air cleaner in an attempt to aid in further exposure reduction. Although there is no proven health benefit from such a measure, some individuals report that they perceive air cleaners as useful in improving their health status.

When considering air cleaners, compare the clean air delivery standard (CADR) and needed maintenance. Always talk to an air filter dealer, and friends who have filters, to find out which is best for you and your home.