Insulated Ducting

20 products

Insulated flexible ducting has an aluminium inner core wrapped in glass wool insulation with an outer sleeve, which cuts condensation, heat loss and noise on ventilation runs. It is the duct to use where an extractor fan or MVHR run passes through a cold loft or void. We stock Systemair insulated ducting from 82mm to 406mm, eFans Direct insulated ducting in 100mm, 125mm, 150mm and 204mm, and Domus EasiPipe insulated flexible duct in 102mm, 125mm and 150mm, all in 10m lengths. Use the size buttons below to filter, or for trade pricing, email hello@efans.co.uk or call 0161 399 3825.

Frequently asked questions

Why use insulated ducting?

When warm, moist air from a bathroom or kitchen runs through a cold loft, the moisture condenses inside an uninsulated duct and can run back into the fan or drip through the ceiling. The insulation keeps the air warm along the run, which stops the condensation. It also reduces heat loss and noise.

Do I need insulated ducting for a bathroom extractor fan in the loft?

Yes, if the duct runs through an unheated loft or void. Insulate the whole length in the cold space, keep the run as short as possible, and fall the duct slightly away from the fan towards the outlet so any condensate drains outside rather than back into the fan.

Is insulated ducting needed for MVHR?

Yes, ducts running through unheated spaces on an MVHR system should be insulated, both to stop condensation and to protect the heat the system recovers. The outdoor intake and exhaust ducts also need insulating where they run through heated space. Check the insulation requirement in your system design or the Domestic Ventilation Compliance Guide.

What sizes do you stock?

From 82mm up to 406mm diameter, all in 10m lengths. Many sizes are imperial: 102mm, 127mm, 152mm and 203mm fit 100mm, 125mm, 150mm and 200mm spigots. Use the size buttons above the products to filter.

How do I fit insulated ducting?

Pull back the insulation and outer sleeve, push the inner core over the spigot and secure it with a hose clip and foil tape. Then pull the insulation back over the joint and tape the outer sleeve so there is no cold spot. Keep the duct fully extended and supported.

Insulated, aluminium or combi ducting?

Use insulated ducting wherever the run passes through a cold space. Aluminium ducting suits short connections and warm air within heated space. Combi ducting adds a PVC outer for durability where the duct may be knocked.