Mouldy Bathroom!

[sandydog]

Hi guys

As in the title, I have a mouldy bathroom. I’ve replaced the extractor fan a while ago with a Manrose VXF100LVS which has a rate of 85m³/h but it doesn’t seem to have made any difference from the last Manrose fan. The main reason I chose this one was ease of replacement.

My picture shows that the mould gathers around this area (also there’s a line directly where showering takes place, and around other various edges of the room. I’m wondering if this is lack of insulation, or with the extractor vent being out there and there are slats which have broken off.

Can anyone please advise so that I can replace the fan correctly?

The room is approximately 6 cubic metres.

Thank you!

 

[just pumps]

Hi guys

As in the title, I have a mouldy bathroom.



I’m wondering if this is lack of insulation, or with the extractor vent being out there and there are slats which have broken off.

Can anyone please advise so that I can replace the fan correctly?

The room is approximately 6 cubic metres.

Thank you!

View attachment 180913

Vent being out where? Broken slats where? Have you looked at the extractor pipe for breaks/ damage?

 

[JohnD]

how long does the fan run for?

how long is the duct?

Does the wind blow against the vent?

have you used a joss-stick or smouldering cigarette to verify that air is sucked out by the fan, and emerges out of the end of the duct? Is there a non-return flap to prevent wind and rain blowing in?

Manrose fans are not very good, you can buy a quieter one, but it will not be much more powerful. Yours is a 12-volt fan, post a photo please showing where it is in relation to the shower and the ceiling. Are you using the correct transformer?

 

[sandydog]

Hi and thanks for the responses. I’m including a couple of photos to show more information. The fan vents out using a flexible duct going up and out, only a distance of 6-8 inches. You can see the broken slat on the picture.

To answer your questions:

I have had the ducting out and couldn’t find any damage.

The fan can run as long as we like, and it’s usually at least an hour!

Wind does blow against the vent.

I’ve done the smoke test and it does pull but only from 3-4 inches away. I left the paper smoking in the sink, 6 feet diagonally away from the fan, and the bathroom is full of smoke after 15 mins. It’s twice as good with the door open a bit, so maybe there’s not enough air coming under the door which is directly opposite the fan and parallel to the shower? The smoke does exit outside.

Interesting you should ask about the transformer. I didn’t use the new one, I just wired into the old one. I’m not sure how different they are, I’ll have to take a look. Could it make a big difference?

 

[JohnD]

I prefer a Cowl vent, it is better at keeping rain out, and does not rattle so annoyingly, or break
https://www.screwfix.com/c/heating-...nt&cm_sp=managedredirect-_-hvac-_cowlvent#_=p

Check for cobwebs or fluff obstructing airflow.

The transformer is probably the same, but worth checking the voltage and amps are correct.

Fresh air should enter the bathroom under the door as you say, is there a carpet or anything blocking the gap?

I take it your fan is over the bath, hence a low voltage model?

Is that a false ceiling? If so you can fit a more powerful and quieter inline ducted fan in the space above, which will do a better job. They are bigger than your current one. Steamy showers create a lot of water vapour and damp. Your existing fan will need to run for a long time to dry the room because it is not very powerful. If it is not annoyingly noisy leave it on constantly and see if that does the trick. I see there is no trickle vent in the window so you are reliant on the fan.

Rigid duct is better than the flexible type, you assemble it with elbow connectors. Worth doing if you change the fan.

 

[JP_]

If fan is working well then it likely is lack of warmth - is the room heating well when the shower is used?
We have a heater and have improved the insulation but still get some mould forming in cold spots. I am guessing there is room above here - maybe the void between floors is cold though?

 

[sandydog]

Thanks both

JohnD I’m going to have a look at the type of fans you’ve suggested as it is a false ceiling. The gap under the door is large enough and not blocked, I wonder if the fan just isn’t strong enough for the be sufficient. The cowl also looks good and cheap!

Jonbey the bathroom isn’t consistently warm. It has 3 outside walls, and nothing above other than insulation and a tiled roof. We have a towel radiator in there but it’s not always on. We’d need to look at a separate method of heating the room. I’d need to look into how difficult it would be to fit a bathroom heater!

 

[JohnD]

see also
https://www.diynot.com/diy/threads/bathroom-extractor-fan-upgrade-suggestions.536981/#post-4530386

 

[JP_]

Thanks both

JohnD I’m going to have a look at the type of fans you’ve suggested as it is a false ceiling. The gap under the door is large enough and not blocked, I wonder if the fan just isn’t strong enough for the be sufficient. The cowl also looks good and cheap!

Jonbey the bathroom isn’t consistently warm. It has 3 outside walls, and nothing above other than insulation and a tiled roof. We have a towel radiator in there but it’s not always on. We’d need to look at a separate method of heating the room. I’d need to look into how difficult it would be to fit a bathroom heater!

Sound like lack of warmth is as much a problem as lack of ventilation. Ventilation is important, but things still get mouldy outside because it is cold and damp, even when there is airflow.

I'd start by improving the insulation in the ceiling above - either pack loft insulation in there, or if the space is limited, sealing in some kingspan or similar to the ceiling boards and topping up with loft insulation.

But with 3 external walls it's always going to be colder than most rooms. In our shower room, which used to have much worse mould on the ceiling, we have an electric fan heater near the ceiling with a pull cord. It's on it's own circuit. Putting that on when showering makes a huge difference to condensation levels.

 

[sandydog]

Looks like I may need to get an electrician in to fit a heater! There are a couple of Dow lights which have gone kaput anyway so it’ll be good to get those sorted. The blooming ceiling is completely sealed with the only access being through small holes, but I know there’s insulation up there.

Thanks so much again, both your advice is really appreciated!