Pressure losses in 12", 14", and 16" non-Metallic flexible ducts with compression and sag Conference Paper uri icon


  • A study was conducted to measure air pressure loss in nonmetallic flexible ducts and included 12 " (305 mm), 14 " (356 mm) and 16" (406 mm) diameter ducts on aflat surface and also positioned over joists on 24 " (610 mm) centers. For this study, flexible duct compression configurations were fully stretched and 4%, 15%, 30% and 45% compressed. Measurements were performed at each compression. All tests were performed in conformance to ASHRAE 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999) with a positive pressure, blowthrough configuration. The data from this study exhibited higher pressure loss than prior Air Conditioning Contractors of America (ACCA) or ASHRAE data. Measured pressure losses were 2 to 13 times higher than round steel ducts. 2009 ASHRAE.

published proceedings

  • ASHRAE Transactions

author list (cited authors)

  • Culp, C., & Cantrill, D.

complete list of authors

  • Culp, C||Cantrill, D

publication date

  • January 2009