Venting for Inline Extractor Fan - Help/Advice

Mumser · 25-02-2020 01:03PM #1

All inline bathroom extractor fan specifications that I can find show the ducting from the fan being vented to the external world. All kits come with an external grille too. Research online indicates that the ducting should not terminate in the attic i.e. end of the ducting from the fan sitting open/unattached in the attic.

I would comply with the manufacturer's specification and what I see recommended online, as it makes sense to me. Sure why would you even have a couple of metres of ducting on the output from the fan if it was only going to remain open inside the attic space?

Can those who know more than me please comment on the two scenarios described. What is the correct installation that one should use?

Alkers · 25-02-2020 01:08PM

I've never heard of anyone ducting an extractor fan just to their attic space?

fred funk }{ · 25-02-2020 03:09PM

Always to the outside. Last thing you want is warm moist air condensing in a cold attic.

Mumser · 25-02-2020 03:58PM

Thanks Alkers & fred_funk. As I say this is what I see from documents online and also what I would expect from my own limited knowledge on this kind of thing. I just want to check, from more experienced people in this area, what they understand to be a valid installation.

I am being told that told that placing the ducting over nearer the edge of our attic (sitting on top or facing into our insulation between the joists) with an open end is a valid installation. To be honest I am astounded by it. From a distance I always thought it had been routed out to a soffit vent. I had no reason to look closer at it.

Currently we have flexible ducting with a lot of water in it sinking down between the joists and a very wet non functioning fan.

I've tried to attach photos of the ducting which comes out from the fan and where it goes in the attic.

Alkers · 25-02-2020 04:05PM

Mumser wrote: »

Thanks Alkers & fred_funk. As I say this is what I see from documents online and also what I would expect from my own limited knowledge on this kind of thing. I just want to check, from more experienced people in this area, what they understand to be a valid installation.

I am being told that told that placing the ducting over nearer the edge of our attic (sitting on top or facing into our insulation between the joists) with an open end is a valid installation. To be honest I am astounded by it. From a distance I always thought it had been routed out to a soffit vent. I had no reason to look closer at it.

Currently we have flexible ducting with a lot of water in it sinking down between the joists and a very wet non functioning fan.

I've tried to attach photos of the ducting which comes out from the fan and where it goes in the attic.

That's ridiculous, why bother duct it at all if it doesn't go anywhere?

Not a big job to get a vent tile and connect ducting from it to the fan. In a cold attic, you should be using insulated ducting or else you will have condensation issues as you're having.

loyatemu · 25-02-2020 04:20PM

at the very least it should be going to the eaves where there the soffits should be ventilated, but through a vented tile is the correct answer.

listermint · 25-02-2020 04:25PM

Mumser wrote: »

Thanks Alkers & fred_funk. As I say this is what I see from documents online and also what I would expect from my own limited knowledge on this kind of thing. I just want to check, from more experienced people in this area, what they understand to be a valid installation.

I am being told that told that placing the ducting over nearer the edge of our attic (sitting on top or facing into our insulation between the joists) with an open end is a valid installation. To be honest I am astounded by it. From a distance I always thought it had been routed out to a soffit vent. I had no reason to look closer at it.

Currently we have flexible ducting with a lot of water in it sinking down between the joists and a very wet non functioning fan.

I've tried to attach photos of the ducting which comes out from the fan and where it goes in the attic.

Whom ever installed that is a joker. Sorry but an absolute joker.

Mould , rot are among the things that will occur.

The ducting is completely the wrong stuff. You need ducting that is insulated. You need a roof tile vent and you need ducting tape.

It's any wonder it's filling with water and the fan is busted too.

awec · 25-02-2020 05:52PM

You can already see all the lovely mould in the fan in the last pic.

GreeBo · 26-02-2020 12:19PM

Mumser wrote: »

Thanks Alkers & fred_funk. As I say this is what I see from documents online and also what I would expect from my own limited knowledge on this kind of thing. I just want to check, from more experienced people in this area, what they understand to be a valid installation.

I am being told that told that placing the ducting over nearer the edge of our attic (sitting on top or facing into our insulation between the joists) with an open end is a valid installation. To be honest I am astounded by it. From a distance I always thought it had been routed out to a soffit vent. I had no reason to look closer at it.

Currently we have flexible ducting with a lot of water in it sinking down between the joists and a very wet non functioning fan.

I've tried to attach photos of the ducting which comes out from the fan and where it goes in the attic.

At least they put in a few u-bends in the pipe:D

Venting for Inline Extractor Fan - Help/Advice

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