Clean the Air With HEPA Filters

A HEPA (High Efficiency Particulate Air) filter can capture 98% of the tiny particles (allergens) in the air. These portable devices range from tabletop to room-size. HEPA filters work best for removing pet dander and pollen, but not as well for dust mites. Look for units tested by the Association of Home Appliance Manufacturers that list the clean air delivery rate (CADR). Make sure the number listed is at least 2/3 of the room's square feet.

Use an Allergen-Trapping Filter

Typical furnace filters don't catch smaller allergens. Pleated paper filters with a MERV (efficiency) rating of 7 to 13 can be almost as effective as HEPA filters and can cost around $10. Electrostatic filters use charged fibers to trap allergens and can cost less than $15. Change filters every three months to maintain unit efficiency. A whole-house HEPA or electrostatic filter unit can be added to your HVAC system, but the cost is more than $1,000

Electronic Air Cleaners

Electronic air cleaners don't use filters or fans. Instead, they change the electric charge on polluting particles. Some electronic air cleaners produce ozone, which can further irritate allergies