Extraction fan in bathroom

[BlueLoo]

There absolutely MUST be ducting to the outside. Typically poked through the eaves gap.

Not an ideal solution.
The damp air gets drawn back into the roof space.

A tile vent is better but needs roof access.

If a duct is not installed, they are hard to retrofit. I'd not bother and put it on the wall/window.

 

[bricksmasher]

Thanks, sounds like a pain

I dont know why neither of them thought about putting one on the external wall

Stupidly i assumed it was installed correctly, im stupid at these sort of things which is why i hire tradesmen

Appreciate the replies

 

[sparkwright]

So, are you saying there is DEFINITELY no ducting from the fan to the outside?

 

[bricksmasher]

So, are you saying there is DEFINITELY no ducting from the fan to the outside?

Nothing that i can see, i tool the photo from where the fan is just above in the loft. I havent been in the loft myself in a while but i cant see where it's ducted anywhere from sticking my head up there

 

[sparkwright]

Typical reasons for NOT installing a fan on an external wall may include:
1) No space on the wall, often a window lintel is present, and drilling a four inch hole under these is not at all advisable.

2) The only wall space may end up over a bath or shower, and the installer has deemed it's not safe to fit a 230v fan here.

3) Can't be bothered to drill a four inch hole and get the cable there.

Tile vents: No proper electrician will want to make a hole in a roof.

Window fans: Cutting a four inch hole in glass is a specialised task.

Which is why many electricians choose to fit the fan on the ceiling and duct out through the soffit.

A possible exception is going through the ceiling a ducting out through a gable end - but your property may not have a gable end.

Going through the soffit may be the only way unless you have someone skilled enough to fit a tile vent or cut holes in glass windows.

 

[bricksmasher]

Thanks, ill get my borther in law to take a look, hes not a sparky but is a great all round builder so sure he will advise what is and isnt possible too

Thanks again for all the replies

 

[bhm1712]

In my opinion, the only type of extract fan that is really worth fitting are the inline duct fans that move circa 300m3 of air an hour.

just fitted this one and it works fantastically. The previous fan like yours did little to remove any condense from the room.

https://www.manrose.co.uk/product/mf100t-mixflo-commercial-induct-fan-timer-100mm/

 

[bricksmasher]

So i spoke the the electrician and said the issues i was having he came back out this morning and went onto the loft and said the ducting was all coiled up and someone had put some insulation over to

So we agreed to have him duct it all outside which he did and showed.me the pics.

Having just had a shower now, i still have eater droplets and a fair amount of condensation on the walls

£500 all up later i dont see any vast improvement on the original fan that was up

 

[BlueLoo]

How did he get the duct outside?

 

[JohnD]

photos in the loft would be most helpful, and from the outside looking at the hose emerging from the eaves.

It is not at all fishy that he is a person who did not bother to use a duct until you called him back....

For the moment, leave the fan running, continuously, for the next hour, with the door and window closed.

 

[EFLImpudence]

Having just had a shower now, i still have eater droplets and a fair amount of condensation on the walls

Perhaps you have an excessively humid house -

Too little ventilation
Several people and animals
Lots of cooking
Lots of plants
Washing drying indoors
Fish tank

 

[bricksmasher]

So had a look outside, i can see this vent in the pic attached

Regards to the house theres no plants, animals, 3 people live here (1 baby, 2 adults) we have a dehumidier running downstairs for our laundry

I cant get into the loft at the moment but ill try take a pic later of what i can see

 

[bricksmasher]

There did seem to be less steam while showering, but still water droplets on the fan itself still

 

[JohnD]

well that's interesting

it appears to be a vent cored through the wall, not poked through the eaves

which is good



though I can't see the flaps being pushed open by airflow (looking again I think it is a plain grille, which is OK). Was the wind blowing towards that wall?

I'm sorry you've spent so much money with so little to show for it.

Both your installers seem to have done a half-arsed job.

Some pics of the vent hose in the loft will help a lot.

The flow with your existing fan may be weak, just run it continuously for now. If you can get a joss-stick, or a smoker, you can watch to see if the fan sucks the smoke.

It's possible to get a better wall-vent, and it may be that your hose route can be improved, but the main thing will probably be to get a more powerful fan.

This is a very good one, and quiet. For best noise suppresion, it can be mounted on a piece of thick ply, covered both sides with synthetic carpet, rubber underlay, or other sound-deadening material, screwed to the loft timbers. This means it will not annoy anyone if it runs during the night. My hearing is poor; I can just hear them if I am in the bathroom, but not if the door has been closed and I am standing outside. Pretty sure your hose and vent will be 4-inch/100mm, and you will need the Timer model. The example I show is suitable for a bathroom with steamy shower, and more than twice the power of your old one. If the hole in your wall is bigger, you can have a bigger duct and fan, and more power.

Same principles as the one shown before by @bhm1712
i have been rather disappointed by Manrose quality and noise in the past.

68 litres per second (Manrose) is 245 cu.metres per hour
and Soler & Palau is 250m3/hr so quite similar.

Your existing fan probably has a nominal air throughput around 80-100 cubic metres per hour, the ducted fans can be two or three times as much, and, being more powerful, can blow air even against moderate winds.

Water droplets on the fan suggest it is cold, possibly cold air is blowing in if there is no non-return flap (easily added) though it would normally warm up with a minute of so once warm air is passing through it. The duct ought to be covered in your insulation so it does not get condensation inside (this is a real problem with flexible hoses, though a rigid duct can be positioned to run downwards towards the wall vent).

 

[bricksmasher]

Thanks very much for the detailed reply and info appreciate it.

I emailed him after my shower and showed him the water on the fan again and the walls that were wet still

To his credit, he came out for the 3rd time today after that and installed an Inline fan, which he said is industrial strength. Free.of charge and replaced the last one he fitted

So will find out tomorrow when the bathrooms in use as to how that goes but it does seem more powerful and its set on fast speed so fingers crossed it will solve the issue have attached photo if it helps

Again, i appreciate all the replies !