Totally encapsulated in aluminium foil for cleaner set up and resistance to grease or moisture ingress in company Traditionally, all ductwork was once fabricated from metal. It needed staying encased in a fire safety procedure when passing through a compartment wall or flooring with no support of a fire damper, https://cristiantjznb.blog-ezine.com/37170344/indicators-on-fire-rated-insulation-for-ductworth-you-should-know