Compression effects on pressure loss in flexible HVAC ducts
A study was conducted to evaluate the effect of compression on pressure drop in flexible, spiral wire helix core ducts used in residential and light commercial applications. Ducts of 6 inches, 8 inches and 10 inches (150, 200 and 250 mm) nominal diameters were tested under different compression configurations following ASHRAE Standard 120-1999--Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The results showed that the available published references tend to underestimate the effects of compression. The study demonstrated that moderate compression in flexible ducts, typical of that often seen in field installations, could increase the pressure drop by a factor of four, while further compression could increase the pressure drop by factors close to ten. The results proved that the pressure drop correction factor for compressed ducts cannot be independent of the duct size, as suggested by ASHRAE Fundamentals, and therefore a new relationship was developed for better quantification of the pressure drop in flexible ducts. This study also suggests potential improvements to ASHRAE Standard 120-1999 and provides new data for duct design.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Assistant Secretary for Energy Efficiency and Renewable Energy. Office of the Building Technologies Program. State and Community Programs. Office of Building Research and Standards; Pacific Gas & Electric Company. California Institute for Energy Efficiency Contract S9902A (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 836654
- Report Number(s):
- LBNL-49012; R&D Project: 884406; TRN: US200504%%246
- Journal Information:
- HVac & R Research, Vol. 10, Issue 3; Other Information: Submitted to HVac and R Research: Volume 10, No.3; Journal Publication Date: 07/2004; PBD: 1 Jul 2002
- Country of Publication:
- United States
- Language:
- English
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