There are several steps you can take to improve the air quality inside your home:
The minimum level of air filtration should be designed to keep your heating and air conditioning system clean. Design considerations must account for an adequate filter face area for the air flow resistance of the filter.
The medium level of air filtration should be designed to eliminate allergen particles like pollen, mold spores & pet dander.
For the maximum level of air filtration, consider electronic air cleaners designed to remove allergen particles as small as bacteria and respirable dust.