If your clothes dryer takes an hour or longer to dry a load of jeans and towels, the problem might lie in the venting rather than the appliance.

Clogged vents that extend drying times cost an additional $18 to $24 a month, said Carl Hein at Dryer Vent Wizard, a Twin Cities dryer vent cleaning service. Longer drying times also reduce an appliance’s life expectancy.

Enter dryer vent cleaning. It’s a niche cleaning service that hardly existed a decade ago. Most dryers used to be in a basement with a simple, short vent to the outside.

As dryers moved upstairs and into people’s living space, vents had to be hidden behind walls and in some cases into attics. “Most people don’t have the expertise to clean the newer, longer vents,” said Hein.

Moistened lint collects on the walls of the vent pipe, reducing efficiency by up to 40 percent, said Hein. A cleaner removes the spitball-like lint with a vacuum, compressed air and brushes.

Dryers working too hard to “breathe” get very hot on the top and cause clothes to be sizzling to the touch when done. A properly running dryer should take only 35 to 40 minutes.

Clean vents are also safer. Each year more than 15,000 house fires are attributed to neglected dryer vents, according to Consumer Reports.

Search for “dryer vent cleaners” in your region online or look in the yellow pages under “dryer vent cleaning.” Many dryer cleaners also service chimneys and air ducts. Prices range from $70 to $175, depending on whether the dryer is vented near the ground or the roof.