Perforations are used to allow extract air into negative pressure ducting.
These duct can only be made as a square or triangular cross-sections. To avoid collapsing it is essential for extract ducting we tension the walls using a combination of suspension profiles, tensioning bolts and threaded bar. Air is drawn into the duct through perforations that can be positioned on any side and anywhere along the length of the duct. To ensure equal extract rates we can adjust the perforation diameters or the gaps between the perforations progressively along the duct. We anticipate our negative pressure ducts will be used where regular and/or thorough cleaning is required.