All About Home Air Filters

The dirt you don't see

With a little attention and elbow grease, home air filters can significantly improve air quality in the home.  Devised to remove tobacco smoke, pet dander, pollen, allergens, mold spores, and airborne toxins and irritants in a room, home air filters clean the air and promote a hygienic environment.  Some scientific studies suggest that air filtration systems, used in conjunction with exposure reduction and adequate ventilation, may help in the treatment of allergies, asthma, and emphysema.

What kind of air filter do I need?

Paper or plastic?

Fiberglass filters, commonly used in home furnaces and central air conditioning systems, protect expensive heating and/or cooling systems from damage caused by collisions with large particles. They trap larger particles like visible dust, but not smaller particles like mold spores, bacteria, or viruses. Inexpensive and simple to install, these filters must be changed monthly during peak usage (summer for air conditioning systems and winter for heating units) or whenever the manufacturer recommends.  Reusable home air filters can be washed and are therefore more ecologically sensitive and economical in the long run than the disposable variety.

Some studies suggest disposable filters made of fabric or paper remove small particles with greater efficiency than reusable fiberglass air filters; because of their smaller pores, common flat or pleated filters-constructed from cotton, paper, or other fabrics-prove adept at grabbing things like pollen, pet dander, or spores.

Deep pleated filters, thicker and more substantial than flat filters, are designed specifically for use with heating or cooling systems.  Although they last longer than ordinary disposable filters, their primary purpose is to protect the furnace or air conditioner; they focus more on filtering large particles out of the air, rather than removing tiny particles for human health.

Electrostatic filters capture airborne particles large and small.  Using the principles of electromagnetism, the charged fibers of the filter attract and hold all variety of particles.  The life of the filter varies by manufacturer, but generally outlasts other types of home air filters.

Electronic air filters remove dust harmful, allergens, and viral or bacterial agents from a room. As electronic devices, they consume electricity and therefore, cost more to operate than other types of filters.  Freestanding devices can clean the air in a single room; larger, more complex systems can run alongside central air systems or heating units and clean the air of an entire house.  Some electronic air filters produce ozone, a potentially harmful chemical. 

More information on air filters