Kingspan Therma™ Duct Insulation

High-performance thermal insulation designed for use on rectangular, circular and flat oval ductwork in HVAC / building service applications. It can be used to insulate ductwork and associated equipment outdoors.

Product Details:

  • The Kingspan Therma Duct insulation has a thermal conductivity value of 0.023 W/mK
  • Euroclass E
  • Comes in sizes 1.2 x 2.4 metres
  • Approximately 1.8kg/n2 at a thickness of 50mm.

*Always Refer Back To The Manufactures Specification Document

Download Specification

Kingspan ThermaTM Duct Insulation is a high performance thermal insulation designed for use on rectangular, circular and flat oval ductwork in HVAC / building services applications.

It can be used to insulate ductwork and associated equipment outdoors, operating within the temperature range of –20°C to +80°C.

Kingspan ThermaTM Duct Insulation is suitable for both new build and refurbishment projects in the residential, commercial, institutional, light industrial and leisure sectors.

Moreover, it is especially suitable for high specification projects where non–fibrous insulants may be preferred, for example: in the food, beverage and pharmaceutical industries; and clean air and hygiene controlled environments.

Kingspan ThermaTM Duct Insulation is CE marked in conformance with BS EN 14308 and a Declaration of Performance is available to download from

Kingspan ThermaTM Duct Insulation Kingspan ThermaTM Duct Insulation comprises a high performance fibre-free rigid thermoset polyisocyanurate (PIR) insulation core, faced on both sides with a low emissivity composite foil autohesively bonded to the insulation core during manufacture.

The insulation core is manufactured with a blowing agent that has zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP).

Kingspan ThermaTM Duct Insulation has a 90% (or greater) closed cell structure and a compressive strength that typically exceeds 140 kPa at 10% compression. Solutions are available to accommodate the surface curvature of circular and flat oval ductwork with an outside diameter (O.D.) of 80 mm or greater.

The rigid nature of Kingspan ThermaTM Duct Insulation enables the specified thickness of insulation to be maintained at the corners of rectangular ductwork and at locations where HVAC / building services equipment is specified.

Non–rigid glass and rock mineral fibre duct wrap products, on the other hand, risk being overstretched and compressed in these locations, potentially leading to a reduction in thermal performance.

Its rigidity also enables the straightforward application of vapour barrier tape and finishing materials which, in turn, facilitates the creation of a continuous and fully sealed vapour barrier. This can provide a neater, closer fitting finish than that achievable with non–rigid glass or rock mineral fibre duct wrap products.


In addition to the information given in this section, it is recommended that reference is also made to BS 5970: 2012 (Thermal insulation of pipework, ductwork, associated equipment and other industrial installations in the temperature range of –100°C to +870°C – Code of practice). Installation

� Care should be taken when handling and transporting insulation products to prevent physical damage.

� During the installation of galvanised steel ductwork, the contractor should place insulated support inserts between ducts and supports, to extend no less than 50 mm both sides of the support to allow for tape application. Insulation at supports should be with a product of suitable compressive strength to carry the loads transmitted to the supports and should be of the same thickness as that of the adjacent duct insulation.

� In addition to the surfaces of ductwork and associated HVAC equipment – flanged joints, stiffeners, fasteners and connections must also be effectively insulated in order to reduce heat loss, heat gain and / or to control condensation.

� To facilitate inspection, testing, adjustment, balancing, maintenance and cleaning, a removable and fully vapour sealed piece of insulation, of sufficient size, must be provided at access door locations, if the door is not already pre-insulated.

� Insulation must not be installed at locations where the ductwork penetrates fire resistance rated walls, partitions, floors and ceiling-floor assemblies. Consideration should be given to current Buildings Regulations / Standards with regard to the requirements for and provision of, fire stops.

� Before being insulated, surfaces must be made clean, dry and free from grease, dust, dirt, loose rust, scale and all other foreign matter.

� The insulation should be installed to achieve a close fit between the insulation and substrate, as well as between insulation joints.

� The ingress of moisture, or other foreign matter, either into the insulation or between the insulation and substrate, should be prevented during installation.

� When insulating rectangular ductwork, the thickness of insulation that has been specified should be maintained at all four corners of the duct.

� On horizontally orientated ducts, the insulation fixed to the sides overlaps the bottom and insulation fixed to the top overlaps the sides (see Figure 1 on page 2 of this document).

� The insulation must be securely fixed to the substrate by means of adhesive, by mechanical fixings or by a combination of both.

� A compatible high–strength contact adhesive, must be applied in accordance with the manufacturer’s recommendations. For suitable adhesives, please contact the Kingspan Insulation Technical Service Department (see rear cover).

� Bands (preferably aluminium) and matching seals are used as additional mechanical means on circular ductwork. The banding must be no less than 15 mm wide and should be applied circumferentially at least three per section of insulation or at maximum 400 mm centres.

� On rectangular ductwork the selection of compatible mechanical fixings will be dependent upon: the substrate material; operating temperatures, size and orientation of the duct and the duct wall; and the degree of vibration to which the duct is subjected during operation.

� Mechanical fixings, if used, must be corrosion resistant, capable of sustaining the calculated tensile dead load perpendicular to the duct wall and securely fixed so that they do not detach from the duct during its service life.

� Mechanical fixings should be positioned so that they are neatly and evenly distributed under each piece of insulation. They should be located no less than 75 mm and no greater than 150 mm, from insulation edges and corners. Vapour Barrier

� The vapour barrier over the insulation should be continuous and fully sealed.

� A high strength self–adhesive aluminium foil vapour barrier tape should be applied to all discontinuities in the vapour barrier. This includes those between insulated duct support inserts and abutting duct insulation, joints, seams, exposed insulation edges, insulation terminations, pin punctures, retaining washers and other protrusions.

� The self-adhesive vapour barrier tape should be applied in a smooth and wrinkle–free manner. It should extend no less than 25 mm either side of joints, seams, insulation edges and terminations, as well as in all directions of pin punctures, retaining washers and other protrusions.

� To ensure successful adhesion, all surfaces to receive self– adhesive vapour barrier tape should be made clean, dry and free from grease, dust, dirt and all other foreign matter prior to application.

If required, surfaces may be primed with a thin coat of compatible high-strength contact adhesive. A gentle pressure may also be exerted using a soft spatula tool, whilst applying the tape.

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