Cleaning your air ducts may seem like a hassle, but the benefits of doing so are more than enough to overcome any inconvenience. If you suffer from seasonal allergies, you know how unpleasant it can be to put up with headaches, sneezing, coughing and watering eyes. But typically, returning to your home can provide some relief from allergies. If your air ducts are harboring allergens, however, being inside can be just as irritating as being outside. In addition to providing a sanctuary from the unpleasantness of allergies, cleaning air ducts may help shorten the duration and intensity of allergy attacks by preventing allergens from spreading onto your clothes, sheets and hair and sticking with you throughout the day. Cleaning air ducts can also discourage unpleasant, lingering odors from remaining in your house. Typically, musty smells and other odors are caused by a combination of dust and moisture. While it's relatively easy to remove dust from visible surfaces, you may still experience offensive odors if your ducts remain dirty. Over time, these odors build up and worsen, so cleaning your air ducts regularly will provide optimal results. As unpleasant as mildew and dust-driven odors can be, they aren't actually the primary problem. The smells are indicative of the presence of bacteria. Whether the source is pet dander, dust, pollen or mildew, the resulting bacteria can cause illness. Such sickness can be difficult to shake if the bacteria can constantly attack you at your home. Having clean air ducts also promotes more efficient operation and better condition of your home's heating and air conditioning systems. If too much dust or any other type of particle builds up in your ducts, it can get trapped in heating and air conditioning equipment, clogging vents and moving parts in a way that can damage the systems. If the problem goes unchecked for a significant amount of time, the damage can be extensive and the repairs can be quite costly. Cleaning dirty air ducts can also provide relief from high utility bills. If dirty ducts are preventing the free flow of hot and cold air throughout your house, you'll have to turn up the intensity of such systems to feel even the slightest effect, or leave them on for longer than you normally would. Over time, this can lead to dramatic increases in utility bills. And because dirty ducts influence both heating and cooling systems, the increased bills will occur year-round, potentially costing you thousands of dollars more than your bill has to be.