Bathroom extractor not so FANtastic???

Hi,

An electrician installed a ceiling mounted fan that goes up into the loft above the shower in our bathroom it then is vented through the gaps in the eves where the walls join the roof. I used it for the first time and it is not extracting much of anything. There is a generous gap under the door but when you get out of the shower there is a lot of moisture still around and the bathroom is still extremely wet.

Can you vent a fan in this way meaning to the gaps in the roof where normally you would have soffits as I have concerns about where or if the moisture is being expelled outside and not into the roof. According to the electrician he has fitted many of these fans without any issues. Any help on what could be creating or causing the lack of suction would be much appreciated.

The house is a 1930's terrace with two bedrooms and a bathroom that is only just big enough for a toilet, sink and a bath with just 1m x 1m manoeuvring room in the middle.....so not huge. The shower we have in there is extremely powerful and high pressured which I do not think helps the steam issue. We are experiencing mould issues due to having the window opening during showering hence the reason for the fan.

Mandy :help:

Hold a sheet of A4 paper up to the fan grill in the ceiling & you should get a good idea of how much suction there is. It should hold it firmly in place. Do you have any heating in the room?

You don't say what make or model extractor fan you have had fitted - but here is a link to a standard ceiling mounted fan which includes the way in which the extracted air should be vented (Discharge Provision) i.e. not directly into the loft.

http://www.tlc-direct.co.uk/Technical/DataSheets/Manrose/BGCF100_200.pdf

The 'electrician' should have given you the installation and user instruction guide when he/she left.

The electrician should also have provided a fan big enough to meet the size of the room and its intended use.
However, most domestic fans needs a fair amount of time to remove moisture after your shower is concluded which is why you should really have a timer fan (one that runs for 20 minutes after your shower ends) fitted.

Hi Mandy, what type of extractor fan is it? ie make and model. I presume it is low voltage? you can then find out the volume of air it extracts and compare it to other fans, it may just be a weak fan?

You'll find in winter more steam is generated, colder temperature = more steam.

As long as the vent hose is going outside somehow you will be ok, I presume he has used a 4" flexi hose, it is important to keep these taught and not hanging about all over the place so may be worth sticking your head into the attic for a look. It won't expel air properly if the hose is poorly installed.

At home I leave the window open for about 30 minutes after having a shower and the steam clears up ok it shouldn't be causing mould to grow.

they do need to be left running for 5-10 mins after the shower to clear the steam.

The fan itself has an over run at the moment of 10 minutes. I did request the information on the fan before installation and I was told is was a trade fan. I have emailed the electrician again to gain this information so someone hopefully can shed so further light on the issue.

The ducting seems in good order and secured and is less than a meter from the fan and then is vented out to the gap in the eaves. When I get the info on the fan I will post it.

Thanks guys

Should be vented to it's own external grill, not clear from your posts if that's the case. Sounds like he's just ducted to the soffit vents....NOT ACCEPTABLE

This is the email that was sent from my electrician today:

Hi Mandy I sent you a message on Tuesday did you receive it?
As the fan I installed is maintenance free there isn't a user guide that comes with it only a installation sheet with very minimal info, ie how to set up overrun, which is completed on installation.

The fan I have fitted is a manrose shower inline fan kit which is capable of venting 23litres of air per second. The general rule for selecting an adiquite fan is it should be able to remove the air in the room 8x in 1hour. The fan that is fitted can remove 82800litres per hour. I worked out your bathroom is around 7.7m3 even rounded up to 8m3 (1m3 = 1000 litres) 8000 litres x 8x per hour is 64000 litres. So the fan is suitable for a bathroom of this size. As I said in the message I will certainly come and check the fan and make sure it's working to its full potential and fetch a replacement to make sure the fan isn't faulty.
The other factor could be if the shower is being used more than average or the external ambient temperature is lower than average this can cause more than average steam and condensation if this is the case we may need to go with a more powerful fan if so I would have to get a price for the fan unit and a gesture of good will would fit for free but would have to charge for the fan unit.
If you let me know what the best time I can come and have a look I will book you in.
Thanks Kevin

The bathroom is consistently and adequately heated throughout the day and in general the house is not a cold house. The fan is ducted to the gap in the eaves where the roof joins the walls and supposedly it does have an external grill on it. I will check on the weekend when i am not up at 4.30am to see if I can see the steam being extracted to the outside properly as I was told it should be visible.