Pre-Insulated Duct — PIR Panel Ductwork

What it is

Ductwork made from rigid PIR panel faced with aluminium on both sides, cut and folded into sections on site. The insulation and the duct are the same component.

Specification at a glance

Property	Typical specification
Panel	PIR core, aluminium facings both sides
Panel thickness	20mm — 30mm typical
Facing	Aluminium foil, thickness stated
Standard	EN 13403 for non-metallic ducts
Fire class	Named EN 13501-1 classification
Pressure limit	Stated by manufacturer; not unlimited

Against GI ductwork

	Pre-insulated PIR	GI with wrap
Void height needed	Less	More
Weight	Much lighter	Heavy
Install sequence	One operation	Fabricate, fit, then insulate
Robustness	Lower; damages easily	High
Pressure capability	Limited	Wide range
Outdoor use	Needs weather jacket	Standard

Where it earns its place

Tight ceiling voids in fit-outs where the slab-to-slab height is fixed and services must be stacked · refurbishments where structural hanger capacity is limited · fast-track programmes where removing the separate insulation trade saves real days · low and medium pressure comfort cooling in office space.

Where projects go wrong

• Used in the wrong location — kitchen extract, exposed plant rooms, or outdoors without a jacket.
• Fire class not checked against the route the duct takes.
• Joints poorly made. The system relies on correct corner profiles and taping; a rushed joint leaks and the aluminium facing tears.
• Hangers over-tightened, crushing the panel and reducing the free area.
• Pressure class exceeded, causing panel deflection and joint failure.

Standards referenced

Non-metallic duct requirements under EN 13403. Reaction-to-fire classification to EN 13501-1. Duct insulation requirements under ECBC 2017.