HVAC systems have shown to act as a collection source for a variety of contaminants, such as mold, fungi, bacteria and dust, which have the potential to affect our health. The removal of these contaminants should be part of an overall plan to improve indoor air quality. Nothing can improve or degrade your health and the quality of your air more than the condition of your HVAC system. Even if you change the filter regularly, dust, pollen, insects and other debris will eventually collect in the system. An annual air duct cleaning is recommended, especially in the fall before the heating system is turned on for the cold months.