Managing the quality of indoor air is a constant concern in every household.  Some of the most important reasons for clean air are:

Whether you have a sophisticated mechanical system or a basic one, you have some sort of filtration mechanism at work. Each filtration system is ranked with a Minimum Efficiency Reporting Value (MERV) rating.  The rating system is ranked from 1 to 16.  The higher the MERV rating, the more effective the filter is at removing particles from the air (FilterAir).

I will begin with a discussion of disposable panel filters that are used in residential situations and then progress to some more advanced filtration systems that are used in commercial applications. (FurnaceFilterCare).  I will finish by discussing some electronic filtration systems that have a high MERV rating and can be used for residential homes.  As you might suspect, the higher the MERV rating the greater the cost for of the system.

Disposable Panel Filters (MERV 1-4):

The standard panel filters that are used in many residential systems have limited effectiveness in their ability to remove contaminants from the air.  The exposed surface area of these filters is small and therefore the ability to collect contaminants is reduced.  Most of these basic filters will not remove any particles less than 10 microns in size.  The thicker versions of these filters can increase the MERV rating as high as 4.  For those without severe allergies, these filters may be sufficient.  However, most homeowners should consider upgrading their filtration systems to higher MERV levels.

Expanded Surface Pocket Filters (MERV 10-14):

These pocket filters are made with multiple layers of synthetic material in the form of deep pockets that increase the exposed surface area for maximum contaminant extraction.  These filters require high volumes of air and are used in commercial and industrial applications.  The depth of the pockets is directly proportional to the MERV rating of the filter.  The deepest pocket filters are more commonly used in laboratory environments and clean rooms (AirGuard).

High Efficiency Particulate Air (HEPA) Filters (MERV 14-15):

HEPA filters are a type of high efficiency filter that are constructed differently than pocket filters.  These filters are made of curvy mats formed with fibers that lay in a random woven pattern.  These filters can remove 99% of particles that are .3 micrometers in size.   Particles are trapped in HEPA filtration systems by 3 methods (Wikipedia):

HEPA filters are used primarily in commercial and industrial environments.  They are also widely used in demolition and high dust construction areas as temporary filtration systems.  For remodeling work in residential environments, consider renting a portable HEPA filter to keep occupied areas free from construction dust and pollutants.

Electronic Air Cleaners (MERV 12):

Duct mounted electronic air cleaners are designed for residential applications and are able to remove airborne particles as small as .01 microns.  These particles include dust, smoke, bacteria, dirt, lint and pollen.  The electronic components give a charge to the airborne particles.  Once the particles are charged, they attach themselves to the electrically charged collecting plates.  This provides a clear supply air stream.  This electronic cleaning system traps particles that are missed by ordinary throw away filters.  Most of these particles are involved in the soiling of walls, curtains and furniture.  These filters are extremely energy efficient.   The monthly cost of operation for one of these systems is less than a 60 watt light bulb (CarrierCleaner.com).

Electronic Air Purifiers (MERV 15):

One step further than the electronic air cleaner is an air purifier.  These purifiers are available for residential applications and use a 3 stage electronic filtration system along with a mechanical filter to capture and kill airborne viruses, bacteria and even mold spores.  For those with severe allergies, this is the best possible equipment for relieving discomfort (CarrierPurifier.com). 

Conclusion:

Whether you are dealing with a new or existing home, air filtration is extremely important.  The quality of the air you breathe is important to your health and well being.  To keep a high level of air quality, you must resort to some type of filtration.  If you are suffering from poor air quality in your home, consider upgrading your filtration system.  Discuss the best system for your needs with your local mechanical contractor.  Check out our resources page for recommendations.