The better a dryer vent blows, the less lint builds up in it.
Short vents blow better than long ones.
Full size dryers blow better than smaller stack dryers or older dryers. Vents with a lot of turns and elbows blow worse and build up more lint. Most vents, however, need cleaning every two to three years, depending on the factors above. Take this Vent Cleaning Test. A plugged vent will certainly cause a dryer to run hotter and increase the chance that something could catch fire.