Pre-insulated Duct

Pre-insulated ductwork faced on either side with an aluminum foil and a polyisocyanurate (PIR) insulation core

Properties: The PIR System comprises PIR Panels, which are faced on both sides with either 80-micron aluminum foil (for internal use) or an 80/200 embossed aluminum foil (for external use) that is lacquered with corrosion-resistant polymer varnish. The core of PIR Panels is a high-performance rigid thermoset polyisocyanurate (PIR) insulant.

The apparent density of PIR Panels is 45-50 kg/m3 when tested to BS EN 1602: 2013.

The compressive strength of PIR Panels typically exceeds 200 kPa at 10% compression, when tested to BS / I.S. EN 826: 1996

The thermal conductivity (λ-value / k-value) of PIR Panels is quoted as 0.020 W/m.K @ 10oC.

Operating Recommendations & Limitations: It is recommended that ductwork fabricated from the PIR System be used for operation as supply, return, fresh, and exhaust air ductwork for heating, ventilation, and air-conditioning systems within the following limits:

80 Micron on Both Sides200 Micron on one side
Mean Air15 m/s35
Velocity (Max.)
Design PressurePositive: 1000 PaPositive: 1750 Pa
TemperatureInternal Air Temperature of -35oC to + 110oC during continuous operation
SizeUnlimited (PIR System fabrication techniques and procedures are strictly observed)

Ductwork fabricated from the PIR System should not be used in the following applications:

  • Conveyance of solids;
  • Fire-resistant ductwork;
  • Kitchen/grease hood exhaust systems;
  • Chemical, fume, or smoke exhaust systems;
  • Where combustible matter readily collects inside the ductwork;
  • Adjacent to any mechanical/electrical sources of extreme heat;
  • Outdoor/underground use without mechanical and/or weather protection; and
  • Where the failure of any type that does not include automatic maximum temperature

Air Leakage:

Air Leakage Standard: BS EN 134403: 2003
Class Achieved: Class C

Water: PIR Panels, and their rigid thermoset insulation core, have a water absorption level of 0.5% per 24 hours of immersion when tested to ASTM C209.

Responsible Sourcing: PIR Panels are manufactured under a management system certified to BS EN ISO 14001: 2015. The principle polymer components of the product are also manufactured under management systems certified to EN ISO 14001: 2015.

Fire: PIR Panels, and their rigid thermoset insulation core, are Class 0, as defined by BS 476 parts 6 & 7. PIR Panels, faced with silver aluminum foil on both sides, are EUROCLASS Cs2d0, as defined by the European Fire Classification System and achieve a Class A when tested to ASTM E 84 / UL 723 / NFPA 255 / NFPA 101 Life Safety Code.

Durability: According to ASHRAE and CIBSE, the indicative life expectancy of HVAC ductwork for building services is approximately 30 years.

Aluminum Duct
Phenolic Pre-insulated Duct