Here are some of the signs that it's time to clean your vent:
Hicks recommends you leave dryer vent cleaning to the professionals. "They have the proper tools and additionally they know whether your dryer vent meets code and they can fix it if it doesn't."
How much does it cost? Dryer vent cleaning is relatively inexpensive given its benefits. A cleaning typically costs between $100 and $150, depending on the length and location of the vent. In addition to the reduced threat of fire, a cleaning can actually pay for itself in less than a year through the improved efficiency with less drying time required.
Hire a pro: Though there are do-it-yourself vent cleaning kits available, they typically aren't as effective as the tools used by professionals. One advantage to having an experienced, qualified and reliable professional clean your system is that he or she has likely seen just about every make and model and will likely be able to clean the interior components more efficiently than you will. Plus, you'll have the assurance that the job was done correctly and safely.
Start with an inspection: A qualified company should do an inspection of the dryer vent prior to a cleaning.
Licensing requirements: The Chimney Safety Institute of America recommends that homeowners look for the Certified Dryer Exhaust Technician designation.
Annual cleanings: Dryer vents should be cleaned at least once a year to reduce the risk of fires, gas leaks, and operate efficiently.
Do not restrict airflow: The transition vent between the dryer and the wall goes INSIDE the pipe leading to the wall. Also, the length for the transition vent should be as short as possible.
Limit the use of dryer sheets used when drying clothing. Instead of dryer sheets for liquid fabric softener.
Only operate clothing dryers for intervals of 30 to 40 minutes per batch of laundry. This allows more air circulation within the dryer and less lint build up from occurring.
When possible hang clothing such as heavy bedding, pillows and other large articles outside to line dry.