Severn Ventilation - Dust and Fume Extraction. Severn Ventilation Ltd has been trading for over 30 years, over which time we have developed a wide range of clients in the manufacturing, automotive, aerospace, chemical, plastics, carpet and even food processing industries. We have extensive experience in the design, manufacture and installation of all types of dust and fume extraction equipment, wood refuse, air conditioning, ventilation and ductwork systems. Our Services Design Services Manufacturing Dust Control and FumeExtraction Heating and Ventilation