The Airwise AWFDI127 is a 127mm diameter, 10-metre roll of insulated aluminium flexible duct. Constructed with a laminated aluminium and polyester inner duct reinforced by a high-tensile steel wire helix — creating a smooth, seamless bore — and finished with an outer glass wool insulation layer enclosed in an aluminium foil jacket, it prevents condensation on the duct surface in cold spaces and limits heat loss or gain in the airstream. The 127mm (5-inch) bore makes it the correct flexible connection for fan units and manifolds with 5-inch spigots, common in North American and some commercial European MVHR equipment. Supplied compressed to approximately 0.6m, it extends to 10m on site and cuts to any length without specialist tools.

About Airwise: A leading UK and Ireland ventilation products supplier based in Tetbury, Gloucestershire — known for quality, integrity, and competitive pricing across the full spectrum of ventilation ducting, valves, and accessories.

127mm

Internal Diameter

10m

Roll Length

Insulated

Glass Wool + Foil Jacket

0.6m

Compressed for Storage

Aluminium / Polyester

Inner Core

127mm (5-Inch) Systems: The 127mm bore is the standard 5-inch duct size used in many commercial MVHR units, kitchen extract systems, and fan coil connections that specify a 5-inch spigot. This is distinct from the common UK domestic 125mm size — always verify the spigot diameter of your equipment before ordering.

Short Runs Only: Use insulated flexible duct for connection and termination sections only — ideally 1.5m or less per section. Extended flexible runs introduce significant pressure drop. Use rigid or semi-rigid duct for all main distribution runs.

Key Features

Aluminium/Polyester Laminate Core

Multi-layer laminated construction with an encapsulated steel wire helix provides a smooth, crush-resistant inner bore that outperforms plain single-layer foil duct in durability and pressure retention.

Glass Wool Insulation Layer

Prevents the duct wall from reaching the dew point of the extract or supply airstream in cold installation environments — essential in loft spaces, cold roof voids, and exposed service runs.

Foil Vapour Barrier Jacket

The outer aluminium foil jacket provides a clean, vapour-tight surface that protects the insulation and gives the duct a professional finish in accessible spaces.

Fire-Rated Construction

The aluminium and polyester construction is fire resistance tested and will not produce toxic gases in the event of fire — an important consideration for duct runs through building cavities.

10m Economy Roll

The full 10m roll minimises per-metre cost and provides sufficient material for multiple fan or valve connections in a single installation, reducing return visits to the supplier.

Tool-Free Cutting & Fixing

Can be cut with scissors or a knife and connected without specialist tools, reducing installation time and tool requirements on-site.

Specifications

SKU	AWFDI127
Brand	Airwise
Diameter	127 mm internal (5 inch)
Roll Length	10,000 mm (10 m)
Compressed Length	Approx. 0.6 m
Inner Core Material	Laminated aluminium / polyester with steel wire helix
Insulation	Glass wool
Outer Jacket	Aluminium foil
Fire Rating	Fire resistance tested; does not produce toxic gases
Colour	Silver
Typical Applications	5-inch fan spigot connections, commercial MVHR flex runs, kitchen extract last-metre connections

Frequently Asked Questions

Is 127mm the same as 125mm?

No — 127mm (5 inches exactly) and 125mm are different sizes. While close, they are not directly interchangeable. 127mm duct will not seal correctly on a 125mm spigot and vice versa. Always verify the spigot diameter on your fan or fitting before selecting the duct size.

How does insulated flexible duct prevent condensation?

The glass wool layer acts as a thermal barrier, keeping the inner aluminium duct surface temperature above the dew point of the air passing through. Without insulation, the cold duct surface in a loft space would cause moisture in the extract air to condense as water inside the corrugation.

Can I use this duct for a kitchen extract run?

Yes — for the connection section between a kitchen extract fan and the rigid duct run. Do not use flexible duct as the primary extraction run from the cooker hood through the wall — use rigid duct for that section. The flex is for the fan connection and vibration isolation.

How do I join two sections of insulated flex?

Use a 127mm rigid duct connector or sleeve with a worm drive clip on each end, then cover the joint with the insulation jacket and seal with aluminium foil tape to maintain thermal continuity at the join.

What is the fire safety classification of this duct?

The Airwise AWFDI insulated flex range is fire resistance tested and certified not to produce toxic gases in the event of fire. For exact classification ratings, refer to the product's test certificate, available on request from your supplier.

Does the 10m roll include any connectors?

No — the roll is supplied as plain ducting only. Worm drive clips and duct connectors are ordered separately as required for each connection point in the installation.

Flexible Duct