Got our en suite redone a couple of years ago and an Airflow Icon ceiling fan installed…ducted horizontally using flexi ducting across loft space (about 5m) and vented under roof eves.

However, we got through 3 of them in so many years as the rotors started impacting the housing plus they clogged up with debris.

Our friendly electrician came back to replace fan again about 3 weeks ago but this time bored a hole through the exterior wall in the loft space above the fan, installed rigid plastic pipe through the wall, an exterior vent cover then some flexi down to the fan. The vertical between the fan and the exterior vent is about 1.5m. This new fan is now making a noise like an old tractor….again!

So…..is the fan installation ok or not?

Must admit not comfortable about the fact we now have ducting through the house wall but I guess this is quite normal?

The exterior vent is just a pretty standard vent on a vertical rendered wall. Should it be something else?

There is also a bit more duct tape than I’m comfortable with where the flexi joins the rigid through the wall…but I know nothing about what is the best method of joining.

Help please!

We install Icon fans with flexi ducting. I’ve had a number rattle due to the fan hitting the flexi – the fan is very close to the top lip on the Icon fans. They often need repositioning or the fixing hole expanded so the flexi doesn’t concertina so much.

I’ve seen plenty of fans with bigger lift than 1.5m and plenty with lots of twists and dips.

I’ve also had to empty large pools of water out of flexi ducting.

Duct tape or cable ties are the norm for joining the flexi pipe.

I don’t like fans mounted anywhere other than on external walls with a short, direct outlet. Warm moist air is going to condense very quickly, particularly in a cold loft space and I don’t think many fans have the capability of extracting sufficiently unless it’s a flat, short run.

If your installation has a fall from the 90 degree bend to the outside vent, even just a small one, I’d say it’s ok.

Without seeing it it’s difficult to say for certain but I don’t think you’ve got anything to worry about particularly.

Rich.

I’d also add that I would rather open a window than have a bathroom extractor fan. If you can do that, turn off the isolator and it’s no longer a problem.

Rich,

Firstly, thanks. I’ll actually take some pics and email them to you if that ok with you. Appreciate a second opinion, thanks.

No, totally enclosed en-suite with no windows.

Just so I am clear, the exterior vent is about 1.5m above the fan…..not below it. However where the flexi leaves the fan, it does drop slightly before heading vertical.

Just so I understand correctly, it is ok to join the flexi to the outlet of the icon directly and seal with duct tape or cable tie?

Looking at the hole through the outer wall I think it needs sealant round it too…and I want to check that there us a fall from interior to exterior rather than the other way round….. If not then how do you block off this new hole in the wall?

What is the total length of ducting?
From the sounds of it, there is quite a lot. Does the fan actually clear the room sufficiently?

Generally a standard axial extractor fan can’t provide much ‘push’ against the resistance of long ducting runs although it can provide a decent volume of air, if there’s little resistance.

We had a failed centrifugal fan replaced with a cheap axial fan (Father-in-Law did it as a favour) and it was rubbish. There was no suck at the vent, because the pipe run in the loft was so long; too much resistance to flow.
We put up with it for a couple of months and then I replaced it with a centrifugal fan (Manrose, I think). It is a bit more unsightly as the housing sits against the ceiling, but they are much more capable of providing decent flows with long pipe runs. Made a massive difference.

We used this one:
http://www.justfans.co.uk/cf200-centrifugal-fan-cf200-p-137.html?osCsid=144c9mnsbfergaf68aeuume115

Further to rwamartin’s comments about the moist air condensing in the loft space, I lagged the duct run in the loft (as we used to get condensed water running back out of the original extractor) and that cured it completely.

If you have had 3 of these fans already fail and the latest one is sounding ill, would it not be better to try a different make of fan, or look at the installation to see what is causing them to fail? Maybe the housing is being distorted at installation causing the fan blades to make contact with the housing.

Have you seen the large axial fans that sit in the loft space?
Like this:
http://www.screwfix.com/p/vent-axia-acm100-in-line-bathroom-extractor-fan/59546
They are a lot more powerful and you just join pipe either side of them and have a vent cover into the bathroom.

We have one of these

http://www.screwfix.com/p/100mm-mixed-flow-fan/26867

(But the older model, this one apparently isn’t as robust).

Sucks like a sucky thing – will be getting another for the second bathroom we have just finished (but that has around 5m of ducting to go thorough so I am hoping this will do the job).

Here you go – the old model

http://www.amazon.co.uk/Manrose-100mm-Standard-Mixed-Flow/dp/B005J3334I/ref=sr_1_1?ie=UTF8&qid=1404202592&sr=8-1&keywords=100mm+Mixed+Flow+Fan

I replaced a crappy ceiling extractor with an inline one and it’s fab.
I think it’s a Manrose and is bigger than I expected! Sucks paper up out of your hand if you hold it within 3″ of the hole in the ceiling.

^^^ Yeah, I might get one of those. We had an extractor put in recently at our new place (ha, well, I say new but we’ve been there 3 years). Up to then, we’ve just been opening the window.
We had a loft instaled fan like that one, but it seems quite weedy, so now the electrickery and ducting is all in place, I might just replace it with something with some real oomph. Will probably mount it properly too on a board with rubber feet to isolate it from the joists a bit.

Just another job on the to-do list!

Will probably mount it properly too on a board with rubber feet to isolate it from the joists a bit.

I was going to do that but I found that a board screwed to a joist and the fan screwed to the board was sufficient.

Benz, no problem sending pictures, my email is in my profile.

Just so I understand correctly, it is ok to join the flexi to the outlet of the icon directly and seal with duct tape or cable tie?

Yes, that’s the way it’s done.

Just so I am clear, the exterior vent is about 1.5m above the fan…..not below it. However where the flexi leaves the fan, it does drop slightly before heading vertical.

1.5m is ok if the fan can lift moist air that far. I’d prefer not to see the flexi drop slightly as it’s effectively a “U” bend in which water will gather if the air condenses before being extracted.

As others have implied, you could fit a more powerful fan that has a greater extraction rate but to be honest I wouldn’t fret about it.

Take a look a couple of times a year and see whether there is any water in the flexi. If not, don’t worry. As long as the fan isn’t venting into the loft (ie the flexi has come undone) then there’s no real issue.

As for sealant around the vent outside, I’d ensure it’s weatherproof but at worst any moisture penetration will just go down the cavity (assuming it’s cavity wall) which is what it’s designed to do.

Rich.

Ohh and we started off with one of these

http://www.screwfix.com/p/manrose-in-line-chrome-20w-shower-fan-kit/71740

But I changed it because my wife’s continual Amazonian Shower Marathons were too much for it and the (fully tiled) en-suite was getting wetter than an otter’s pocket.