Traditional ducting systems have changed little in over a hundred years, with the exception of the introduction of foam board ducting products in the 196os, but these have not gained any real traction commercially: while they do appear on sites from time to time, their market share is very limited. The invention of a pre-insulated duct supplied in flat-panel format presents a different prospect, which was recently recognised by the company winning the 2015 Irish Times InterTradeIreland award for most innovative product. Indeed, PanelDuct has also secured worldwide patents throughout Europe, United States of America, Japan and China with patents pending in other territories. The idea of PanelDuct came about when Walsh Mechanical Engineering spotted a consistent problem in building fit outs and ventilation ductwork. It provides a solution to an unmet need in ventilation systems. Traditional galvanised metal ductwork is generally quite bulky, proves costly to deliver and requires significant storage space onsite. In addition, this metal ductwork is delivered to site preassembled, but not insulated. A second fix of insulated duct wrap must be fixed, once the duct is installed. This second fix is costly, labour intensive and time consuming. If the duct runs external to a building, a third fix of protective cladding must be added to prevent rainwater from spoiling the duct wrap. (Rainwater present in duct wrap allows the conduction of heat, and so, defeats the purpose of the insulation.) Non-insulated galvanised steel had been the standard form of ventilation ductwork for many years. Specifications are drawn up by engineers, detailing the shape, size and routing of the required duct system. These drawings are given to the fabrication shop where a sub-contractor trims standard galvanised steel sheets to the required flat pattern, folds the material into a rectangular cross-section, joins the seam and assembles roll formed flanges on either end. Ultimately, the job of installing insulated ventilation ductwork involves three separate tasks, by three different crews. Savings are made in transport costs, labour time and by automating a process that, up to now, has been very labour intensive. Overall labour can be saved by utilising economies of scale in the factory. The foaming operation is optimised and the foaming press is operated by dedicated staff in an efficient work-balanced manner. Once the panels are picked, they are palletised and dispatched to site, for next day delivery. It is the very modular nature of the panel widths that allow them to be pre-manufactured in an optimised work-balanced process and built to stock. Accordingly, there is no waiting time for fabrication. PanelDuct can accommodate the full size and range of any ventilation system including all fittings and accessories. Panels are easily adapted to overcome unexpected complications with onsite modifications.

Features and cost benefits


For high profile exterior installations, PanelDuct can be supplied with a durable flange coving, matched to any RAL colour, concealing all flanges and connections. As PanelDuct needs no external cladding, it offers unparalleled aesthetics. In addition, to the flat-pack modular concept, we have incorporated enhanced features into the engineering development of this innovation, such as unbeatable air tightness (expand), acoustic (noise) absorption, and the option to have the panels pre-lined with anti-microbial lining for cleanroom applications. Each of these features has specific cost benefits:
  • The engineering rule of thumb is to call for an extra 15% of air delivery, to allow for leakage in traditional ductwork. An airtight system will not need this extra capacity, hence lower plant (air handling unit) costs, and also lower running costs, resulting in a lower carbon footprint.
  • Ductwork systems often need to incorporate attenuation units, which are specific ‘air baffles’ placed within ductwork to cancel out the noise of the air handling unit. Panel Duct is internally lined with polyurethane foam, which in addition to its heat insulation, offers noise insulation, meaning that the attenuation units are simply not required in PanelDuct systems.
  • Traditional cleanroom ventilation requires a high efficiency particulate air (HEPA) filter, with an incorporated ultraviolet light air purifier to eliminate bacteria. These expensive items are not required when the duct itself is lined with an anti-microbial coating.
PanelDuct is ideal for high specification projects where pressurised clean air delivery is assured at minimal operating costs. The system can be installed in both new and retrofit projects with full compatibility to join up with traditional galvanised sheet ducts. PanelDuct has been successfully installed in several projects in Ireland and internationally as seen in images below. [caption id="attachment_30940" align="alignnone" width="663"]PanelDuct® in Tesco, Dundalk (left) and Dunnes Parkway, Limerick (right) PanelDuct® in Tesco, Dundalk (left) and Dunnes Parkway, Limerick (right)[/caption] [caption id="attachment_30941" align="alignnone" width="663"]PanelDuct® in Digiplex Data Centre, Sweden PanelDuct® in Digiplex Data Centre, Sweden[/caption] Ventilation systems built with PanelDuct bring airtightness to unprecedented levels. All panels feature integral compression seals, creating an innovative airtight system. Ductwork fabricated with PanelDuct has minimal air leakage, even at 2500Pa, which far outperforms any other system currently available. Accordingly, the CO2 emissions and energy running costs of PanelDuct systems are the lowest achievable. The loss of filtered, heated or chilled air into voids and other unused parts of buildings through which the ducts pass or outside the structure altogether is expensive and an analysis which looks at the cost of generating the energy in the first place reveals unnecessary lifetime costs which the end user must pay. EN1507/DW144 provides a methodology by which various systems can be tested with classifications ranging from Class A to Class D indicating the percentages of leakage with are permitted to comply with each specific category. Certified by BSRIA, PanelDuct exceeds Class D airtightness by 50%. The concept of pre-insulated flat pack ducting panels can be employed in any application where the conveyance of insulated air is required, so smoke extraction, fire rated ducting, underfloor air delivery and many more applications could be future applications for investigation. There are opportunities to explore manufacture from alternate materials, such as stainless steel or aluminium for special applications, or even pultruding the profile in a glass fibre composite through an extrusion die, where non-metal ducting is required. The applications are not limited to rectangular cross-section ducting. The concept can be expanded in the future to include circular and flat-oval ductwork.