Seeing as you lot seem to know everything (give or take):

My bathroom is suffering from a lack of ventilation and my partner taking far too long in the shower for my energy bill.

I want to add some form of ventilation however I don’t really want to just have a hole through the wall type vent fan, ideally I wanted one with the extractor in the loft that vents elswhere.

However the elsewhere is the issue – the roofline on my 1930’s house means I dont think I can vent through a hole in the sofit and I dont have a gable end wall to pop a hole in Thusly:

Is there anywhere is can vent it – though a vent in the roof or through the rear chimney stack which is no longer connected to a chimney below having been removed?

Mine vents in to a special vent in the roof, just replaced a tile I think.

Got one of them ^^^^ & the problem is that the high vapour content condenses out either in the duct or the fan within the roof space even with a fairly short & insulated duct run, so will be replacing with a through the wall vent as soon as I can

Mine vents in to a special vent in the roof, just replaced a tile I think.

This

Apparently the vent through a special roof tile is a thing! I never knew!

I wonder how much of a pita it is to get a vent tile to match and to install it?!

I’ve got exactly that arrangement, even with the same fan ( Toolstation ). You need to use insulated ducting – it both stops water condensing and makes it quieter. Also a non-return flap to stop the wind blowing in. I also couldn’t get it out through the soffit so I used a ventilation tile. Our roof is old and unlined with loose clay tiles so getting the tile in was easy; a modern roof would be more of a problem. It’s been in for a few years now and works fine.

Take a look at Heat recovery ventilation. It replaces the air aswell as venting and recovers some of the heat, you can get away with one of the through the wall ones this way, or you can go for a remote unit like you pictured.

We’ve got one similar to that – Aventa AV-100T I think.
If I was going to do it again, I’d go for a 125mm (5″) unit, rather than the 4″, just to get more air moving.

I can’t comment on the roof tile vent solution as ours could go in the soffit, but the tips about insulating the ducting & using a one way flap to prevent wind blowing back down the tube are good ones.
Keep the duct runs as short as possible so you get maximum flow & to reduce the risk of the moist air condensing.

Apologies for jumping in with my question. I need one too but have a crawl space in the loft of bathroom (lean-to style roof) and a wall I can ventilate through. Can I just wire it up to come on with the light or do I need a separate switch for it?

Snap. Same sort of house, same sort of problem. It initially looked as though I could reach the soffit, but lots of crawling around in crap (and cutting a small hole in the soffit) last weekend confirmed the opposite. Roof tile is the next option.

I went for a powerful inline extractor from screwfix – on special offer at about £50 at the moment. You can get a sprung non-return flap which prevents the flap from rattling about.

Can I just wire it up to come on with the light or do I need a separate switch for it?

You can, if you have access to the switch from above. However, if it has a run-on function, you’ll need a permanent live from somewhere. A separate fused switch somewhere in between tends to be recommended.

do I need a separate switch for it

No doubt a qualified sparky will turn up soon but the fan usually has a separate power supply with an accessible isolating switch. A sense line then goes to the light so that the fan comes on with the light but the fan normally has a delayed turn-off so that it keeps running for a few minutes after the light goes off.

Apologies for jumping in with my question. I need one too but have a crawl space in the loft of bathroom (lean-to style roof) and a wall I can ventilate through. Can I just wire it up to come on with the light or do I need a separate switch for it?

It is normal to have an isolator switch to enable it to be maintained without having to have the power off (and thus the light). Also, a fan needs a permanent live if you want to have it overrun – ie run on after the light switch is turned off.

Ensure that the fan can extract sufficient volume of air. There is a building reg. which applies to this. If you’re going upwards or over any great length horizontally a large airflow is going to be required. Try to get a run with no kinks or U bends in it where water can condense and settle. A downward sloping run, maybe in 100mm soil pipe rather than flexible ducting is preferable.

Rich.

Just fitted 2 of those in-line fans (bathroom and on-suit) to replace the old ones in the loft. The old ones just vented into the roof space and my wife can spend a good 30minsint eh shower!

I have a similar roofline with no gable ends and managed to get it out through the soffit. At first I did not think I’d be able to, but the flexi ducting was squashy enough that I could get it through the gap between the top of the wall and roof, and once through it returned to about 90% of its original round shape.

I will probably replace the duct with insulated ones as I found quite a lot of condensation in the duct I put in 3 weeks ago when fitting the second duct this weekend. The fan is very good, following a shower there is no steam left in the air and just the smallest amount on the mirror

Thanks! 🙂

I will probably replace the duct with insulated ones as I found quite a lot of condensation in the duct I put in 3 weeks ago when fitting the second duct this weekend. The fan is very good, following a shower there is no steam left in the air and just the smallest amount on the mirror

Dunno how good the insulation is on those – but I’m planning to wrap a roll of the foil tape around the existing duct and reuse it.

If you get insulated ducting it remains as steam for longer increasing the extraction efficiency. Once past the fan unit it will start to form water so try and get the ducting to the outlet vent as short as possible and if through the eaves then ensure it is on a slopping that way. You may need to raise the height of the fan to ensure this.

Thank you all for the helpful information! I knew this was the place to ask.

Stay tuned for next weeks topic of ‘How do I fix a one_happy_hippy shaped hole in the ceiling?’ or ‘my roof now leaks really badly’ or possibly ‘i electrocuted myself installing an extractor fan’…

We’ve got one but it’s not that great. Last one to bed opens the bathroom window and shuts the door. First one up for a piss – by which time the bathroom is bone dry – shuts it again so it’s warm in the morning. A bit old fashioned but it seems to work.

We’ve got one but it’s not that great. Last one to bed opens the bathroom window and shuts the door. First one up for a piss – by which time the bathroom is bone dry – shuts it again so it’s warm in the morning. A bit old fashioned but it seems to work.

Unfortunately in my household this would resort in
a) it never being opened by 50% of the population.
b) it never being closed by 50% of the population.
c) 50% of the population complaining its cold all the time.

Also because the bathroom is pretty cold the tendency is for the steam to condense almost instantly and with the shower / window locations its not really practical to shower with the window open.

We’re not allowed to leave the bathroom windows open any more or the cats will leg it. Not that this would bother me entirely, the dirty little buggers.

Hence the mould explosion and need for a more powerful extractor.

If you get insulated ducting it remains as steam for longer increasing the extraction efficiency. Once past the fan unit it will start to form water so try and get the ducting to the outlet vent as short as possible and if through the eaves then ensure it is on a slopping that way.

Good tip. Thanks

Hence the mould explosion and need for a more powerful extractor.

A recommendation from this forum regarding Mould was using HG Mould cleaner. I followed this recommendation and can also highly recommend it.

Done it twice this winter already, it’s back already.

[video]https://youtu.be/jqBzxUaHKi4?t=22[/video]

I bought this extractor for the bathroom earlier this year. Very powerful and quiet too. I didn’t get it from Screwfix though as I found it on ebay and could specify the hoses and vents to go with it.

That’s the one I’ve got. Seems like the screwfix offer has ended.

I don’t think that Manrose one linked to above has a run-on timer. They do a version that does have a timer.

This is the one I went for:

http://www.fastlec.co.uk/airflow-aventa-av100t-timer-fan-100mm-mixed-flow-2-speed

but like I say above if I was to do it again, I’d get the 125mm version for an extra £12 or so. It shifts a lot more air.
Both of them are 2 speed, which you fix depending on how you wire it up – there’s a jumper that you can bridge to alter the speed. I set mine to fast, with a mind to slowing it down if it proved too loud, but it’s fine as it is.

one happy hippy.

I have one of those in the garage, with a flappy vent thing and flexible ducting. used for about a month.

Let me know if your interested in a purchase

Its this one

http://www.amazon.co.uk/gp/product/B00FDTKL8E?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00

I don’t think that Manrose one linked to above has a run-on timer.

It doesn’t – deliberately avoided it because I don’t have a permanent live in the loftspace. But the amount of air it shifts suggests that a run-on might not be needed anyhow.

The Manrose one does have a run-on function – I have two and they are both set to run on and both have a separate fused/switched live feed.

I didn’t know about insulated ducting though so thank you for that – that’s a project for the Spring.

Ohh and apparently the older version (linked above to Toolstation) is better than the new model (linked above to Screwfix) – better made and more reliable.

Well, that’s a nuisance. Will they work with just a switched live? I had to stick an extra wire from the switched live terminal to the permanently live terminal on the current fan just to get it to turn on at all.

johndoh – Member

The Manrose one does have a run-on function – I have two and they are both set to run on and both have a separate fused/switched live feed.

Manrose do one that does have a timer (the MF100T), but the one linked to (MF100W) doesn’t seem to have the timer – at least it’s not mentioned.
I wasn’t trying to be pedantic; just didn’t want the OP to use the link to get to an item, thinking it had a timer when it doesn’t.

From what I can remember of the internal workings, I don’t think it would be a problem – there was a live, switched live and neutral when I wired mine up (old style ones like Toolstation above)

Manrose do one that does have a timer (the MF100T), but the one linked to (MF100W) doesn’t seem to have the timer – at least it’s not mentioned.
I wasn’t trying to be pedantic; just didn’t want the OP to use the link to get to an item, thinking it had a timer when it doesn’t.

Fair enough – I was going to say there might be different models then promptly didn’t.

Ohh and I got the first one from Screwfix and the second from Amazon as it was much cheaper at the point of purchase 🙂

The house we’ve just moved into has a Wilts Plus 100mm ceiling fan with flexible ducting in the loft leading to a roof vent.
The fan seems to work fine (I’ve taken it apart & cleaned it) but it gets absolutely no airflow drawing into it. Any ideas?

As Stumpy said you can get them with a timer, mine is but purchased through eBay. The wiring is simply to do. The speed is set by moving a wire. There is little difference in noise levels between the speeds so I just left it on full speed which I think is the default

Is the insulated ducting any quieter than the normal stuff? We’ve got one of those MF100 fans on a very short length of aluminium ducting but it’s set to medium speed because it’s a bit loud otherwise; not the fan as such but just the whooshing of air…

it makes a massive difference. You still hear it but it’s a dull noise rather than the whistle you normally get. Don’t get it from screwfix though as its twice the price through them.

Interesting, thanks. Something to look at when I get round to fixing the backdraught shutter that clatters when it’s windy, even though it’s a sprung one…

budgierider67 – Member
The house we’ve just moved into has a Wilts Plus 100mm ceiling fan with flexible ducting in the loft leading to a roof vent.
The fan seems to work fine (I’ve taken it apart & cleaned it) but it gets absolutely no airflow drawing into it. Any ideas?

How long is the ducting? Axial fans do high volumes with low resistance. If there is a long duct run it might not be able to push hard enough to get any flow.
We had an axial fan in our bathroom with only about 2m of duct, but there was barely any flow.
Swapped it to one of these inline fans with more oomph and it clears the air very quickly.

Another thing to check is whether there is any available air for the fan to move. If the bathroom door seals too tightly in the frame, the fan night not be able to draw enough air in to create any flow.

Centrifugal fans are better where you have long duct runs. We installed a Manrose one in our last house and it was very effective. Only downside is the impeller housing is quite large and is basically a box on the ceiling.