According to the NHAPS (National Human Activity Pattern Survey), the average individual spends 87% of their time indoors. So whether simply for comfort of for matters of health, individuals should be aware of the array of air purifications and treatment options available to them with their forced air system.
The most basic form of air purification exists in the filters located somewhere in the return ductwork. These filters form the first line of defense in combatting the dust and allergens in the air. The filters are given a MERV (Minimum Efficiency Reporting Value) rating from 1-16, with lower vallues functioning solely to keep pollen and pet hair to a manageable levels and higher ratings being able to filter bacteria out of the air. Most homes typically implement filters with a MERV rating 7-12, with the higher rated filters 13-16 only being used in hospital and other health sensitive areas. These filters are only beneficial if they are habitually replaced at least once a season.
In homes where mold and bacteria are a concern, the inclusion of a UV Lamp can aid in maintaining a healthy household. UV Lamps are placed within the ductwork itself and disinfect the air as it passed through the system. Only the air exposed directly to the UV Lamp is disinfected. But as with air filters, UV Lamps only have a limited life before they need to be replaced. A typical bulb lasts 1 year of continuous use before it will burn out.
Central humidifiers are placed on the ductwork adjacent to your heating or air conditioning unit to add moisture back into the air as unit is warming or cooling the house. By controlling the amount of moisture in the air, we can prevent everythign from nose and throat irritation, chapped lips and flakey skin, and even damage to the home itself cause by exceedingly dry air. Even regions with traditionally high humidity can benefit from such systems as the very act of cooling or heating the air draws the moisture out of it. Homes that have been sealed up tight to prevent the outside temperature from infiltrating the house are now faced with the danger of over conditioning the air and drying it out beyond comfort and health levels. Again it is important to realize that humidifiers will also need to be serviced once a year and for the water panel to be replaced.