New Long-Turn Elbow for Dryer Venting
(Jupiter, FL -March 2006) UL Test Results on Long-Turn Ell versus standard Elbow. The manufacturer's of The Dryer-Ell, a re-engineered long-turn dryer exhaust conduit fitting, recently underwent some extensive laboratory testing by Underwriters Laboratories.

The testing was to determine the positive impact a long turn elbow would have on the efficiency of the dryer appliance. The test would measure the volumetric air flowrate through the commonly used 4-section adjustable 90 degree ell and the new long turn smooth ell. The standard 4" sectioned ell currently being used exhibits an approximate 3.5" radius, and according to most codes, provides a negative equivalent length of allowable duct run of five feet. The new Dryer-ell was engineered to provide a one-to-one ratio of equivalent length by providing two things: a smooth interior and a much larger radius. The 10" radius Dryer-ell measures 18" long at its centerline and according to the ASHRAE Fundamental Handbook methodology of calculating friction loss, saves the tradesman approximately 4.5 lineal feet of duct run.

In order to achieve acceptability in the industry, Rick Harpenau, owner of In-O-Vate Technologies, contracted with UL to perform a series of test with the intentions of proving just how efficient the new ell was. The Fact-Finding Report from UL provided some surprising and interesting results.

The testing showed the impact of a standard 4 section 3.5 inch radius ell was more severe than the building code currently indicates. Placing a standard 4 section 3.5 inch radius ell in the exhaust conduit results in an equivalent pipe length of 15 feet, not the 5 feet the code indicates. When a smooth interior 10" radius elbow was installed in the test layout, the equivalent pipe length of the elbow was only 2 1/2 feet. The smooth radius ell was 6 times more efficient than the 4 section 3.5" radius elbow in flow movement through the fitting.

A few changes may occur from these test results, but the most likely one is that a Code Change Proposal will be reviewed by the International Code Council in September dealing with the long awaited increase of total length of dryer conduit from 25 feet to 45 feet. For years the industry has lobbied that the new dryers produced had a minimum exhaust duct length capacity of 45 feet or more.

With the knowledge of the overly restrictive sectioned ells, the council may agree to the 45 feet maximum length and adjust the deductions to 15 feet for the sectioned 90 degree ell and 2.5 feet for the new long turn ell. 45 degree ells will be respectively half of the new numbers.

For the tradesmen and the general contractors, this is a huge benefit, as the old 25 foot length was very restrictive and limited their options for proper or aesthetic terminations. If they use the old sectioned ells, they will be at or about the same results as they are prior to the change, but throw in the new equivalent length for the long turn Dryer-ell, and you have a very attractive alternative.

In the past, builders would account for the longer distances required by adding a dryer booster fan. Besides being expensive, they become a huge bottleneck in the conduit when they malfunction of stop running. They are generally located in crawlspaces and attics with minimal access. Likewise many municipalities are disallowing their use.

The new long-turn Dryer-ell from In-O-Vate appears to be a breakthrough product for an industry struggling for a solution. We found them online at for less than $15.

About In-O-Vate Technologies
In-O-Vate Technologies, Inc., located in Jupiter, FL, is a manufacturing company focused on the development, manufacturing, and marketing of dryer venting products. With four patents issued and others pending, the building industry has benefited from In-O-Vate's commitment to innovation and persistence.
Contact Information:

Rick Harpenau
In-O-Vate Technologies, Inc.
810 Saturn Street, Suite 20 • Jupiter, FL 33477
Phone: (561) 743-8696 • Fax: (561) 745-9723