The importance of the right access door
In any commercial or residential ductwork system, it is important that access points be provided to facilitate cleaning, inspections, and other maintenance activities.
Access panel sizes are standard across the industry and are either circular or square/ rectangular in design. Where a standardised access door does not fit a duct design then a removable panel made from sheet metal may be installed; this is not always ideal, but this critically enables access for maintenance.
Matt Saunders, Regional Sales Manager for Air Services at Swiftclean says,
“It’s vitally important that access doors are fitted at regular intervals so our engineers can make sure the complete system is accessible for cleaning. Our client will then be compliant with the requirements of TR19® or TR19® Grease. It also helps our sales team to supply accurate quotations before the work is carried out”.
Once suitable access has been cut by the engineer, access door frames that comprise of tabs are folded over by hand, then crimped to the ductwork itself. The door is then able to be put into place within the frame, and using the cam levers, locked into place. Intumescent seals on the access door help to create a seal to avoid any unwanted draughts, as well as expanding in the event of a fire to prevent the spread of fire and smoke.
In some cases, a chain may be added between the access door and frame; this is particularly important when access doors are fitted to the underside of ducting as it avoids the risk of injury should the door fall for any reason.
Duct Design Stage
At the duct design stage, designers and contractors should consider man-loading. This is especially true when dealing with large ductwork which requires man access to the interior of the duct. The responsibility of designing and fitting the bracketry will often fall to the ductwork contractor.
When it comes to commercial ductwork systems, having properly sized access panels is essential to the cleaning and maintenance of the systems as a whole. As such, designers and contractors alike must be aware of the recommended sizes and given the appropriate considerations and approvals before deviating from them.
Designers/specifiers and contractors must pay particular attention to the location of access panels when designing systems. They should clearly state the type of panels required, the sizes and the locations in the specification.
Contractors should make sure that panels are installed at the levels recommended by the guideline. This will help ensure that the ductwork is accessible for regular cleaning and maintenance.
Fitting Access Doors Post Installation
In many cases, when the maintenance contractor attends the site to maintain or clean ductwork, the access may not be fully sufficient for the process.
For example, quite often we come across a site where access has been installed for inspection only (small-sized access door sizes, spread thinly), which would not facilitate a full system clean.
“An access door needs to be in an accessible position, ideally on the side of ductwork, as it’s likely to be used on a regular basis for cleaning,” said Richard Crews, Swiftclean Compliance Coordinator and BESA GHO3 and GHT3 Course instructor. He added, “According to TR19® Grease, access doors should be fitted at a minimum distance of two metres apart to enable hand cleaning, whilst also preserving the integrity of the duct. Although if you enter the duct, of course with the correct confined space training and in accordance with the risk assessment, there must be a minimum of two access doors (one for access and one for egress), which also of course helps with ventilation when in the ductwork.”
In conclusion, when it comes to access panels, designers/specifiers and contractors should pay extra attention to ensure they are meeting the requirements stated in TR19® Grease for kitchen extract systems, and TR19® for ventilation systems.
Proper consideration of these requirements will result in the installation of access panels of the correct sizes in the right locations, providing the right accessibility for cleaning and maintenance.
