ductwork

It is expected that many countries will between 2015 and 2020 have regulations imposing requirements for new buildings which are near-zero energy targets. This has major consequences:  
Post date: 21 May 2010
Type: Topic

Although this seems to be true, this is a dangerous generalization. There are many factors that govern airtighness of round ductwork, including roundness (any slight ovality can cause leakage at the joints) and the flatness of the seams at the joints between two ducts (protuding or convex seams can cause point leakages at the joint irrespective of the gasket type).
Post date: 19 Apr 2010
Type: Ask the Experts

This is generally not possible. In systems with good airtightness, the leakage flow rates are too small for one to be able to accurately measure the flow rate over the fan.For more information you can check-out the Webevent presentation “Duct System Leakage Testing — Methods, requirements, handing over” by P.G.Schild, available on the website www.asiepi.eu
Post date: 19 Apr 2010
Type: Ask the Experts

In general, yes. For more information you can check-out the Information Paper P187 “Duct System Air Leakage — How Scandinavia tackled the problem” by P.G.Schild & J.Railio, on the BUILDUP website
Post date: 19 Apr 2010
Type: Ask the Experts

A good starting point is the paper "stimulating better envelope and ductwork airtightness with EPBD" by Carrié et al., at the AIVC 2008 conference (www.aivc.org).Another possibility is to check out the presentation “Including leakage in energy calculations” by Dr. J-R Millet, held at the ASIEPI web event on ductwork airtightness (http://www.asiepi.eu/wp-5-airtightness/web-events.html)
Post date: 19 Apr 2010
Type: Ask the Experts

Post date: 13 Apr 2010
Type: Publication

Content Scope Introduction Air transport through ductwork Ventilation principles Thermal forces and wind forces Ducts and ductwork components Duct form System lay out and Sizing methods Duct insulation Fire safety Acoustics Air filters Duct hygiene and cleaning Duct tightness Duct construction materials Strength Hangers and supports Fundamentals of duct flow aerodynamics Flow rate balancing and control References
Post date: 13 Apr 2010
Type: Publication

Post date: 13 Apr 2010
Type: Publication