Mechanical engineers and building services installers face a growing set of challenges as we head into 2023, writes John O’Gorman, national sales and specification manager, Kingspan Technical Insulation Ireland.

The rising energy costs and drive towards net zero means that developers are looking to minimise the energy demand from building services while the lingering effects of the pandemic mean that air quality is now under greater scrutiny than ever before. Add to this the ongoing skills shortages impacting the industry, and it is a daunting list.

The Kingspan KoolDuct System is an innovative pre-insulated phenolic rectangular HVAC ductwork system.

In response to these challenges, many are now turning to modular approaches such as pre-insulated phenolic ductwork systems. These systems offer a range of potential benefits, allowing improved installation speed and adaptability, supporting clean air distribution, and delivering air-leakage rates which can be a fraction of those of conventional ductwork – potentially greatly reducing system operational costs.

The lightweight phenolic ductwork system can be rapidly installed and is capable of achieving low levels of air-leakage, reducing long-term energy demands and cost.

Installation savings

Traditionally, HVAC ductwork is constructed from galvanised sheet steel, which is installed first and then insulated separately as a second operation. This makes installations a lengthy and labour-intensive process, particularly for larger dimensions of steel ductwork, and space must also be left for the ductwork to be lagged once in place.

In contrast, pre-insulated ductwork systems are formed from rigid phenolic insulation panels faced with aluminium foil on both sides. These panels can be used to fabricate ductwork in sections up to 2.95 m long. With no need to instal insulation in a second fix, the runs can be fitted flush with floors, walls and ceilings, saving up to 200 mm in a single dimension.

Pre-insulated phenolic ductwork can be as much as 75% lighter than a comparative sheet metal system with mineral fibre lagging. In addition to reducing structural support requirements, this lightweight design means it is possible to join several sections of ductwork together at floor level (up to 15 meters in length) and lift and fit them in a single operation – further speeding up installations.

The pre-insulated panels can also be easily modified and adapted onsite with standard tools, making it much easier for site teams to manage unexpected changes to the design which may create obstructions in the planned run.

Enhanced performance

In addition to these benefits during installation, pre-insulated phenolic ductwork systems can also offer a range of operational advantages. The low thermal conductivity of their rigid phenolic insulation core makes them the most thermally efficient, and hence the thinnest, insulation product commonly used for pre-insulated HVAC ductwork. It also makes them well suited for use on high specification projects where non-fibrous insulants may be preferred.

The fabricated ductwork sections can also be highly airtight, with systems capable of meeting air–leakage Class C and D both at low and medium pressures (ref. BS EN 1507: 2006; BS EN 13403: 2003 and BESA DW/144). This can allow the desired air flow rates to be met with smaller, more efficient fans, potentially significantly lowering long-term energy demand.

Lasting benefits

Pre-insulated ductwork offers clear answers to the challenges facing the industry, allowing project teams to achieve faster installations with lower labour demands and greater adaptability. At the same time, their highly airtight and insulated design can provide long-term energy savings for building occupants whilst also potentially cutting operational carbon emissions.

For more information: Kingspan Insulation Ltd, Castleblayney, Co Monaghan. T: +353 (0) 42 975 4219. E: