Most of the air you breath comes from your ventilation system and this system must be cleaned periodically to keep the air you inhale clean. This matter can not be overlooked as breathing in dust particles and other debris that tend to accumulate in your ducts is hazardous to your health. While on the topic of duct cleaning, the necessity of dryer vent cleaning cannot be ignored - clogged vents can lead to inefficient drying which, in turn, will lead to higher power bills. Recommendations for frequency of cleaning range from six months to three years, depending on use and the type of dryer and vent blows.