Round EPP Duct, 1.5m Length — 125mm, 160mm & 200mm

Description

The Casavent Round EPP Duct is a rigid duct section, 1.5 metres long, manufactured from Expanded Polypropylene (EPP) in two interlocking halves. Being made of EPP, the duct is inherently insulating, so runs built from this material typically don't need a separate insulation wrap — useful for reducing condensation risk and heat loss on exposed or loft-void ductwork.

The two-half construction allows the duct to be fitted around obstructions or opened up during installation, which can simplify routing in retrofit projects compared with a single-piece rigid tube. It's available in three diameters to match the airflow needs of the run — 125mm, 160mm, and 200mm.

3 Sizes

125 / 160 / 200mm

1.5m

Length

25mm

Wall Thickness

0.039 W/m·K

Thermal Conductivity

ATC3 (C)

Air-Tightness, up to 1000 Pa

Class E

Fire Classification

System Component

This is a component of the Casavent EPP radial ducting system — connecting fittings and couplers are sold separately.

Insulating by Nature

EPP has a low thermal conductivity of 0.039 W/(m·K), so duct runs built from this material provide useful thermal insulation without a separate wrap, helping reduce condensation risk and heat loss.

Very Strong — Can Be Stood On

With a 25mm wall thickness, the duct is strong enough to be stood on, giving it a level of impact and load resistance well beyond thin-wall flexible or sheet-metal ductwork.

Two-Half Construction

Manufactured in two interlocking halves, the duct can be opened and fitted around existing services or obstructions, which can simplify installation compared with feeding a single-piece rigid tube through a void.

High Air-Tightness Rating

Rated to ATC3 (C) air-tightness, up to 1000 Pa, giving a high standard of sealing for ducted MVHR/MEV systems where minimising air leakage matters.

Three Diameters to Match Airflow

Available in 125mm, 160mm, and 200mm, so the duct size can be matched to the airflow demand of each run without over- or under-sizing.

Corrosion-Free

As a moulded plastic component, the duct is immune to corrosion, unlike galvanised steel ductwork, giving long service life in damp loft or void conditions.

Product Code

Diameter

Length

RD125-1.5M-EPP

125mm

1.5m

RD160-1.5M-EPP

160mm

1.5m

RD200-1.5M-EPP

200mm

1.5m

Technical Data

Material

Expanded Polypropylene (EPP)

Wall Thickness

25mm

Thermal Conductivity

0.039 W/(m·K)

Structural Strength

Very strong — can be stood on

Sealing / Air-Tightness Classification

ATC3 (C), up to 1000 Pa

Fire Classification

Class E

Service Temperature

-25°C to +80°C

Microbial Resistance

Rating 1a, Method A (EN ISO 846:2019)

Specification Notice

This product is manufactured in two interlocking halves, per the manufacturer's specification.

What is this duct made from?

Expanded Polypropylene (EPP) — a rigid, lightweight, and inherently insulating material, 25mm wall thickness.

Which diameter should I choose?

125mm suits lower-airflow runs, 160mm suits mid-capacity runs, and 200mm suits the highest-airflow duct runs in the range.

How strong is this duct?

It's rated as very strong — strong enough to be stood on — thanks to its 25mm EPP wall thickness.

What air-tightness class does this duct meet?

ATC3 (C), rated up to 1000 Pa, giving a high standard of sealing for ducted ventilation systems.

What is its fire classification?

Class E.

Does this duct need extra insulation?

EPP's low thermal conductivity (0.039 W/(m·K)) means duct runs built from this material typically don't need a separate insulation wrap, unlike bare metal ductwork.

What does 'two interlocking halves' mean for installation?

The duct is manufactured in two halves that interlock together, allowing it to be fitted around obstructions or existing services rather than needing to be fed through as a single piece.

What connects to this duct?

Matching-diameter round bends, tees, and PVC couplers from the same Casavent EPP range.

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