The most common causes of fire from residential dryers are easily preventable. About a third of dryer fires in the U.S. occur because people fail to remove lint buildup in the dryer or exhaust duct. Dryer Inspection Tips: Make sure dryer ducts are at least four inches in diameter and as large as the dryer outlet. The dryer’s exhaust duct developed length should not be longer than 25 feet. To determine developed length, consider that each 90-degree turn adds five feet. Ensure