Client: Verplas Ltd
Industry: HVAC, Construction
Services: Design Consultancy

An insulated ducting range made entirely from EPS completely reinvented the solution, reducing heat loss and install times.


Advances in materials, tooling and foam moulding technology allow Engineered Foam Products (EFP) to manufacture increasingly complex product shapes. In the case of Verplas Ltd, this involved moulding an insulated ducting range, as a more sustainable alternative to the traditional thin extruded plastic systems. Our EPS material was sufficiently thermally efficient to even exceed stringent building regulations. EFP also manufacture numerous components for HVAC applications but even with this expertise, thin-walled ductwork presented its own set of unique challenges.

Description of Situation

Historically, the installation of extruded plastic ducting has proved labour intensive and time consuming, requiring two people to complete the process. For plastic ducting of this nature to achieve building regulation requirements, a thermal wrap (typically a mineral wool blanket) needs to be cut to size down to size and secured with tape, the joins have to be sealed with both glue and tape to complete an insulation cover. It’s a difficult process where it is hard to achieve airtight joints to prevent heat loss.

Project Scope

The introduction of insulated ducting manufactured entirely from a grey expanded polystyrene (graphite impregnated EPS) completely reinvented the solution and changed the install process. The moulding when integrated with the Verplas Rapid Self Seal fitting simply push-fits together without the need for additional tools or materials, creating a more environmentally friendly solution which is also much lighter and cleaner to install.

Key Features & Benefits

    • Improved thermal insulation

    • Compatibility with chosen heat recovery system

    • Tighter more reliable seals reduce system heat loss

    • No need for extra connections or components

    • Push fit for faster and easier product install

    • Material cost savings in comparison to other ducting products

The Insulated Ducting Project

With Verplas seeking a new ducting system that had quick installation times at its core, EFP worked in partnership to design an expanded foam system which would eliminate the need for any further insulation and ensure that assembly could be achieved quickly by one person. The insulated ducting would need to remain compact as per its plastic counterpart, requiring a thin wall EPS moulding that needed to be resilient to handling whilst providing sufficient insulation to meet the required thermal building regulations.

The one-metre-long duct sections were always going to be the most challenging components of the Verplas system to manufacture. Engineering the sliding cores of the tool to ensure their significant weight did not cause them to move out of alignment, required a fresh approach. EFP worked closely with the specialist manufacturer of the moulding press to design and develop a bespoke tooling solution to ensure the stable and precise alignment of the cores within the mould cavities. This close collaboration between EFP, the customer and the toolmaker helped to ensure consistency of the wall thickness along the full length of the ducts, preventing lateral movement as the cores move back and forwards each cycle.

Customer Quote

“The EPS Thermal Ducting system performs very well, we are very proud of the products, and we believe it is the best solution on the marketplace. Working in partnership with EFP over the last 6 years has proven to be a good joint venture. We are excited about the growth potential of the product range; we foresee the thermal product become a bigger percent of business in the years to come”.
Derren Gittins, Managing Director at Verplas Ltd

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