Ventilation Ducting

What Is Ventilation Ducting Used For?

Ventilation ducting is used to carry air between different parts of a building and an external outlet. Common applications include:

• Bathrooms and kitchens – Extracting steam, odours, and excess humidity at the source.
• Lofts and voids – Discreetly routing airflow through difficult-to-reach areas.
• MVHR systems (Mechanical Ventilation with Heat Recovery) – Supplying and extracting air as part of a whole-house mechanical ventilation setup.
• Commercial buildings – Delivering fresh air and removing airborne contaminants in workspaces.
• Industrial spaces – Managing fumes, dust, or high-temperature air in factories or workshops.

Types of Ventilation Ducting Available

Round Ducting

Round ventilation ducting is the most commonly used option for extractor fans and MVHR systems. It offers minimal air resistance and it's ideal where space is available and high airflow is required.

Sizes available:

• 100mm
• 125mm
• 150mm

Rectangular Ducting

Rectangular ventilation ducting (also known as flat channel or low-profile ducting) is designed for installations where height or space is restricted, such as in ceiling voids, behind kitchen cabinets, or between joists. It offers a space-saving solution without sacrificing airflow efficiency.

Sizes available:

• 110mm x 54mm
• 204mm x 60mm
• 220mm x 90mm

Compliance with UK Building Regulations

Proper ventilation isn’t just best practice, it’s required. All ducting installations must meet the standards set out in Building Regulations Part F, which include minimum airflow rates, insulation requirements, and system design guidelines.

Key requirements include:

• Bathrooms must extract at least 15 litres/second.
• Kitchens require up to 60 litres/second (or 30 if using a cooker hood).
• All ducts running through unheated areas (e.g. lofts) should be insulated to prevent condensation.
• Backdraft dampers are recommended to prevent cold air or smells re-entering when fans are off.
• Fire dampers or collars are mandatory where ducts pass through fire compartment walls or floors (as outlined in Part B).

Following these standards helps reduce the risk of mould, structural damage, and inspection failures.

Energy Efficiency and System Design

Well-designed ductwork supports the overall energy performance of your ventilation system. Here’s how:

• Use smooth, rigid ducting wherever possible to reduce resistance.
• Keep duct runs short and direct with minimal bends.
• Avoid flexible ducting for long runs, it creates more drag and sags over time.
• Seal all joints to avoid air leakage.
• Insulate ducts in cold zones to stop heat loss and condensation.

These steps help your system run quieter, last longer, and consume less power.

Why Buy From Us?

We’re a trusted UK supplier of ventilation ducting and accessories, with options for both trade professionals and homeowners. Here’s what we offer:

• A full range of round and rectangular ducting
• Lightweight, durable PVC construction
• Fast UK delivery and FREE shipping on orders over £250
• Expert technical support to guide your purchase or installation

If you're unsure what type of ducting you need, get in touch, our team is always happy to help.