In several communities in Norway, Norsk Hydro ASA, a fortune 500 company, operates large aluminium plants. At the heart of the community – both figuratively and literally – Hydro has a responsibility to run them as quietly as possible. Flebu has supplied fans and ancillary products to Hydro for over ten years. One example is the plant at Hoyanger in Ardal. Here, Flebu supplied flue gas fans, together with the complete filter unit and silencers. As the plant is situated in the middle of the town noise levels are kept below 85 dba.