Keeping Household Air Clean: Types of Air Cleaners and Filters

HEPA Air Cleaner

Passes air through a filter to remove pollen, dust and other airborne allergens.

Uses a high-efficiency-particulate-arresting (HEPA) filter.

Often used in medicine, atomic energy and semiconductors because of their superior air-cleaning ability.

Can trap as much as 99.97 percent of particles 0.3 microns or larger.

Designed to trap allergy-causing pollen and mold spores, as well as filter out smoke and dust mites.

Electrostatic Air Cleaner

Works best for whole-house filtration

Filter used consists of shredded polypropylene fleece that has been given a permanent electric charge to help attract and remove submicron-sized allergens.

Does not remove gas molecules from the air.

UV Air Cleaner

Uses a HEPA filter as well as ultraviolet light rays to clean air.

Also acts as a germ killer to remove virus, mold and bacteria from the air.

Some units have a pre-filter as the first line of defense against larger particles. It is the less expensive filter and extends the life of the more expensive HEPA filter.

Ionizer Air Cleaner

Use an ionizer to clean air by charging molecules of air, which helps make indoor air more refreshing.

Ionizer technology in an air cleaner can also reduce static electricity and improve the filter’s efficiency.

Fiberglass Filter

Designed to protect the heating and air conditioning system from large particles, heavy dust and lint.

Protects furnace from larger particles and lint that enter the HVAC system.

Most common type of filter.

Fibers are not dense or electrostatically charged, so they cannot attract and capture smaller-sized particles.

This type of filter should be changed at least once a month.

Most common size for all furnace/AC filters are 20”x 20”, 20”x 25”, 16”x 20”, 16”x 25” and 14”x 25”.

Pleated Filter

A low-cost alternative to fiberglass filters, designed to protect the home’s HVAC system from dust.

Made of a dense and efficient cotton/polyester material.

The pleated design provides greater surface area to capture more particles than fiberglass filters.

Smaller sized particles can pass through the filter because fibers are not eletrostatically charge and the media must be woven with spaces between fibers to allow adequate airflow.

This type of filter should be changed every 90 days.

Electronic Filter

Filters the entire home by installing in the duct system.

Only operates when the furnace or AC blower is running.

Typically must be installed by a professional.

Electronic cells must be cleaned regularly.

Permanent Washable Filter

Consists of a flat panel of various woven synthetics.

Considered permanent because homeowners can rinse it free of particles and reuse it.

Should be rinsed every 30 days. Filter usually lasts 5-6 years.

Some brands have an anti-microbial agent that inhibits growth of mold, mildew, bacteria and fungi in the filter.

An electrostatic charge develops as air passes through the filter. The charge, however, varies with humidity and the furnace or A/C blowing cycles. This means some particles may fall off the filter, pass through it and re-enter the air stream.