Many people take this one for-granted. Just as it is important for us to eat nutritional food, we also must consider the quality of the air we breath. Start with replacing the air filter in your A/C system on a monthly basis. Not only will this provide for better air quality, but it also can prolong the life of the system and save you from a lot of trouble down the road. The filter protects the evaporator coil from getting dirty and clogged.
A dirty coil can also lead to very poor air quality. As dust, animal fur, sand, and other pollutants build up on the coil, a sludge forms that begins to hold moisture. This provides an ideal location for mold growth. The air you are breathing in your home must then pass through this coil during the operation of the A/C system. If you notice a black dust near your vents, this could be signs of mold growth and you may want to have your A/C system inspected.
Deposits near your air vents may also indicate a problem with you duct system. If your duct system has leaks, you may be pulling hot air into your duct system. This hot air mixing with the cool, air conditioned air, leaves room for condensation to form and again a cool damp area is a good place for mold to form.
Other things that can help control and improve the indoor air quality of your home are things such as, UV lights, electronic air cleaners, or media filtration systems. Proper maintenance done on a regular basis can help to identify problem areas before they become serious.