LAB REVIEW AND
ORIGINAL BY:          John Lockmiller     DATE:   4-25-96       

DUCT EROSION TEST

  Tests were performed in compliance with UL 181 and ASTM C-1071.  The tests consisted of duct free blow of 10,000 feet/minute for one hour, and a four hour test at 10,000 feet/minute.

  One air duct erosion test was performed, per the requirements of ASTM C-1071 on 24" X 24" ESMI dual wall duct.  The test was performed at the American Warming & Ventilating test laboratory in Bradner, Ohio

  The duct liner sections were assembled and connected to the AMCA (fig. 5.5) test setup and (fig. 6.5) flow measurement apparatus, on the downstream end of the tapered transition.  Air flow was increased from zero (0) until a center line velocity of not less than 10,000 feet/minute was obtained.  Velocity was measured by means of a Pitot Tube (at the end of the duct) connected to a portable manometer.  We ran a duct free blow for one (1) hour checking velocity periodically.  At the end of the hour, we positioned a cheesecloth collector approximately 1 foot downstream of the end of the duct.  We then ran a 4 hour test checking for anomalies at one (1) hour intervals. (At each hour interval, velocity was checked to be sure a 10,000 feet/minute minimum was maintained.) Every hour during the test the collector was inspected for erosion, using tape.  No noticeable anomaly on the tape determined a successful completion of the test.  Following on the next page is a list of materials and duct construction used in the test.

  Upon completion of the testing, there was no constant or increasing rate of erosion.  There was no visual evidence of flaking or delamination of the air stream surface.

  The test was deemed successful based on the criterion designated in UL181 and ASTM C-1071.