Did you know that most homes generate about 40 pounds of dust per year for every 1500 square feet of space? An innovative whole house HEPA/charcoal system that works in tandem with a residential heating/cooling unit may be the ticket to cleaner air in your home.  Some designs not only filter the air inside the home, but filter fresh air drawn in through a dampered vent from outside.  

There are several companies that manufacture whole house air filters. There are minor variations, but the main thing they all have in common is that the filter is installed in an air duct. An HVAC professional should be the one to install the whole house air filter.

Unlike common "electronic air cleaners," otherwise known as electrostatic precipitators, a whole house HEPA/charcoal system is ozone-free.  The 99.97% efficient HEPA filter performs at a clinical standard that is required for hospital operating rooms.  Different configurations of charcoal filters are available for odor and chemical vapor control.
 
The ducted system can be installed in a vertical or horizontal configuration.  

For most homes, a minimum airflow of 1000 cubic feet per minute is required.  Systems offering 400 to 600 cubic feet per minute are not a good value.  In that case, you would be better off purchasing one or two portable air cleaners and positioning them near the intakes for the "cold air return" to your furnace or air conditioning system. 
 
Ozone generating ionizers are not effective, and pose potential health risks.  The EPA, many governmental health agencies, and the Lung Association have warned about the use of ozone generators.  The only legitimate "whole house" air purifiers are installed in air ducts.
 
The system should be installed in such a manner that it does not have the potential to shut down or damage your central heating/cooling system if the filters become clogged because of improper servicing, or because of blower failure.  Whole house HEPA systems can interfere with heating/cooling if they are not installed properly.  Don't buy a whole house system from any company that does not include an installation design with your purchase, and support to make sure it is done right.
 
A truly effective "whole house" system is not cheap.  They cost between $2000 and $3000. If your budget is under $1000, then portable HEPAs are a good alternative.

Some whole house air filters fit in the home’s forced air furnace/air handler or can be used as an independent system mounted in the attic, crawl space or closet. Some whole house air filters use charcoal and some use carbon along with a synthetic media filter.

Manufacturers suggest that the synthetic media filter be changed every 90 days and the carbon or charcoal one every 5 years.

Whole house air filter manufacturers are constantly upgrading their products and the consumer is the winner in that situation. Cleaner indoor air means less cleaning and more time living!