This article presents the Swedish experience with the implementation of quality ductwork systems and describes the requirements introduced in the AMA (General material and workmanship specifications) quality assurance system based on subsequent partial testing.
The article highlights the importance of a tight ductwork and focuses on the requirements for tight ventilation ductwork systems which were included in AMA already in the early sixties. It presents the ductwork airtightness demands in AMA from 1966 to 1972 and lists the tightness classes (permissible leakage rate at a specified test pressure) evolution until 2007. Furthermore, it explains how the tightness is tested and by whom and examines whether the testing is worth the money. A comparison performed in 1999 between test results in Belgium, France and Sweden found Swedish typical duct systems between 25 – 50 times tighter than those in Belgium and France.
This Swedish way of working has proved to be very effective in raising the quality of ductwork. The long-time focus on ductwork quality in Sweden has resulted in very low air leakage in normal Swedish duct installations which has promoted air quality, thermal comfort and sustainability.
Download the full article at: http://www.rehva.eu/fileadmin/hvac-dictio/01-2013/p28-32_swedish-experience-with-airtight-ductwork_rj1301.pdf