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Kingspan Therma™ Duct Insulation is an energy efficient rigid insulation for rectangular, circular and flat oval HVAC ductwork installed outdoors, suitable for both new build and refurbishment projects in the residential, commercial, institutional and industrial sectors.

Insulation located outdoors must be protected with a compatible weatherproof material.

Kingspan Therma™ Duct Insulation comprises a fibre-free rigid polyisocyanurate (PIR) insulation core, faced on both sides with a protective low vapour permeability trilaminate foil.

Insulated duct support inserts:

Load-bearing insulation inserts can be fabricated from standard Kingspan Therma™ Duct Insulation boards for ductwork installed outdoors.

Flat rectangular strips of Kingspan Therma™ Duct Insulation are used on support brackets with rectangular and flat oval ductwork. Curved strips of Therma™ Duct Insulation (crocodile strips) or strips of Kingspan Tarec™pir Pipe insulation are used on support brackets with circular ductwork.


Kingspan Therma™ Duct Insulation boards are manufactured to the highest standards under a quality control system certified to:

  • BS EN ISO 9001: 2015 (Quality management systems. Requirements).
  • BS EN ISO 14001: 2015 (Environmental Management Systems. Requirements).
  • BS OHSAS 18001: 2007 (Health and Safety Management Systems. Requirements).


Kingspan Therma™ insulation is CFC-free and HCFC-free, with zero Ozone Depleting Potential (zero ODP) and Global Warming Potential (GWP) ≤5.

Green guide rating:

Kingspan Therma™ Duct Insulation boards have been assigned a BRE Global Green Guide Rating of A+.


The score obtained by Kingspan Therma™ Duct Insulation from the life cycle assessment of BRE Global Environmental Profiles Methodology is Methodology is available online at Green Book Live, Certificate no. 500. The lower the Ecopoints, the lower the environmental impact.

BES 6001:

All Therma insulation boards manufactured by Kingspan Insulation in the UK are certified to BES 6001 ‘Excellent’ (Framework Standard for Responsible Sourcing).

Standard product features


Kingspan Therma™ Duct Insulation is faced on both sides with an extremely durable and protective low vapour permeability trilaminate foil autohesively bonded to the insulation core during manufacture.

Thermal conductivity:

0.023 W/m·K at 10°C mean and 19°C mean.

Thermal performance:

Satisfies the requirements of the Non-Domestic and of the Domestic Building Services Compliance Guides, BS 5422: 2009 and the TIMSA Guide.

Fire and smoke performance:

  • BS 476-7: 1997: Class 1.
  • Euroclass: E.

Compressive strength (minimum):

100 kPa at 10% compression.

Closed cell content:


Nominal density range:

25–30 kg/m³.

Operating temperature limits:

-20 to +80°C.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
90-45-25/350 Pre-insulated ductwork and fittings

Product specification

An important note about specifying



Kingspan Insulation


+44 (0)1544 388601

Product reference

Kingspan Therma™ Duct Insulation

Board size

[600 x 1200 mm]
[1200 x 2400 mm]
[Contractor’s choice]


[20 mm]
[25 mm]
[30 mm]
[40 mm]
[50 mm]
[___ mm]
Refer to manufacturer's literature or Technical Services department for details of available thicknesses.

Manufacturer details

Kingspan Insulation Ltd,
Herefordshire, HR6 9LA
Tel +44 (0)1544 388601
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NBS National BIM Library