A clothes dryer is one of the hardest-working appliances in your home. It is also a fairly basic appliance in how it operates, and if it’s properly vented and maintained, it should give you years, of reliable service. To insure dryer ventilation is done correctly, an inspection is an easy and cost effective way to determine the efficiency of the ventilation.
If the duct is in a heated space, such as the inside of the house or in a finished basement it doesn’t need to be insulated. If it’s running through the ceiling to a crawl space/attic, a basement or other unconditioned space where freezing is possible, the duct needs to be insulated. Insulation helps prevent the moisture in the exhaust air from freezing inside the pipe, which would later lead to condensation and potential moisture problems when the pipe warms up and the ice melts.
Your dryer only has the power to push that heavy, wet lint so far, so it’s inevitable that some of it is going remain behind in the vent pipe. As I mentioned before, a buildup of lint in the vent reduces the air flow and affects your dryer’s performance, so it should be professionally cleaned out periodically.
How often the venting is cleaned is a matter of how much use your dryer gets. Large families that do lots of laundry should consider having it cleaned every six months, while someone living alone and doing laundry once a week or so might need to have it done every 2-3 years.