This department of Aquila Triventek specializes in high pressure water cleaning equipment from small to large, from cold to hot and up to ultra-high pressures. Recycling water is a speciality and duct cleaners may be interested in rubbish or garbage chute cleaning equipment.
Go to the online shop, Technical and Safety department, to buy HVCA TR19 Guide to Good Practice: "Cleanliness of Ventilation Systems". There are also other technical standards documentation for the professional duct cleaner
North American Insulation Manufacturers Association: proactive in discussing insulated, fibre glass/mineral fibre constructed ductwork and cleaning issues
UK Chartered Institute of Building Services Engineers (CIBSE)
CIBSE publishes TM 26 'Hygienic Maintenance of Office Ventilation Ductwork', which deals in particular with microbiological issues (testing methds and benchmarks)
HAS specialises in manufacturing 'commodity' ductwork, especially circular, and a wide range of duct ancillaries such as access panels, flexible ducting etc
The largest group company, HDL manufactures and installs ductwork, on projects ranging from Heathrow Terminal 5 through to the 'Gherkin' tower in the City of London.