As Underwriter's Laboratories confirmed when studying the Dryer-Ell, even straight pipe contributes to airflow friction loss. As duct runs get longer (or as sectioned elbows are added), back pressure increases. This makes it more difficult for the dryer to evacuate lint that is normally pumped out from every cycle. If the run is too long, the risk that lint will build up enough to create a fire hazard increases dramatically. This is a very serious threat: According to the US Fire Adminstration, there are more than 15,000 dryer fires every year. The code restrictions are designed to reduce that risk.
Dryer-Ell is designed to provide a 90° turn without any run length reduction. With its four inch diameter, which is standard for dryer duct pipe, and its overall eighteen inch overall length, the Dryer-Ell is very useful for taking advantage of the maximum allowable exhaust duct length. Its longer radius and smooth interior improve dryer performance and are 500% more aiflow efficient than sectioned elbows.
Visit Dryer-Ell.com today to check out both the LT90 and the LT45 for shorter runs.