The intricate maze of air ducts, vents and heating and cooling systems designed to make your home comfortable, may in fact, be making you uncomfortable or even sick. Your air system plays host to a variety of pollutants, such as molds, mildew and dustmites to name just a few. These impurities commonly cause allergic reactions, breathing difficulties, infections and disease. If your home is one year old or more, these contaminants could be clinging to every square inch of your air duct system.