kopkidda Registered User


I am going to fit a flexible pipe to my extractor fan,this fan requires a pipe of diameter 6 inches,is it possible to get flexible pipe that would fit onto this pipe?And also the vent on my wall needs to be replaced,is it possible to get a vent for the inside of my kitchen that this pipe would fit into?

Do I have to replace my external vent also?

RKQ Registered User

Need afew more details to be able to help. It is possible to get a 4" pipe and a downsizer. Not sure what type of external vent you have. 6" flexible pipe is hard no get off the shelf.

How long a pipe do you need? Does it have to bend?

I did buy a stainless steel island hood with a 6" pipe and used 4" foil flexible pipe. The vent manufacturer will have them.
Cost a lot of time and money to organise a downsizer from a 6" to a 4", even thought the shop was fully aware of what I was planning to do before I purchased the hood.

It would be possible to get an extractor hood that could connect to the existing 6" pipe. It might be necessary to downsize to 4" foil flexible pipe and seal it as it joins or fits into the 6" pipe (airtight seal)

kopkidda Registered User

RKQ said:

How long a pipe do you need? Does it have to bend?

(airtight seal)

I need a pipe of about 2 metres,ye it has to be one of them flexible ones.

So I could buy something in the shop that fits over the outside of the extractor fan that downsizes it to 4 inch and then i could use the 4 inch pipe?

Do you have any idea where i cud get one of these?

RKQ Registered User

2 m long 4" (100mm) diameter aluminium foil tubes are readily available in all good hardware and diy stores.
Plastic bending pipes are also available but are usually used for vent slates etc. Other contributers may recommend insulated pipes - which can be expensive but can prevent condensation of air in pipe. I suppose it depends on position of pipe.

If this pipe is in a ceiling then consider packing around pipe with fibre glass or Rockwool insulation - between joists, if possible.

It should be possible to get a "downsizer" to fit to existing 6" pipe. Connect 4" foil to 4" side of downsizer and connect to 4"extractor fan / downsizer (4" to 6").
Or you could fit 6" to 4" downsizer to fan, fit foil pipe and insert same into 6" pipe. Use spray foam to seal gap between pipes; or cover connection of pipes in 50mm aluminium tape - good overlap = air tight seal!

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