Huge condensation in the bathroom, what to look..? Any tips..?

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I noticed huge condensation on one of the bathrooms (used by my teenager!). Water actually not just makes wall wet it actually comes as drops near windows and walls. I did all basic checks listed below, all looking good ..

1. Checked fan, which works fine makes noise when bath light is on and goes off 2-3 minutes after switching off light
2. Checked fan while steamy inside and noticed visible hot air exit from fan
3. Checked ducting and seems to be intact, now planned to use tape to ensure duct end covers well with light end

What I could not check are..
1. If fan end is dirty and stop exit or steam (as no access), but from distance I can see hot air exiting
2. Couldn't check for any holes in duct from light end to fan end?

Other doubt I have is about the bathroom paint, its not seems to absorb any water..Is that expected..? Paint seems to be peeling off due to condensation in the bathroom. Not sure if previous owner used wrong paint..?

See some photos..
My other bath is similar aged and similar construction no problem at all. everything is this toilet may be 10 year old.

Any suggestions..? tips..? Thanks
 

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I noticed huge condensation on one of the bathrooms (used by my teenager!). Water actually not just makes wall wet it actually comes as drops near windows and walls.
That's how the world works with water vapour and cooler parts.

1. Checked fan, which works fine makes noise when bath light is on and goes off 2-3 minutes after switching off light
Turn it up to its maximum - usually 30 minutes.
 
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Your have a poor quality fan. A typical cheap builders fan has a throughout nominally around 80 cubic metres per hour. You can easily get three times that. It looks to me like you have a 100mm flexible duct above the ceiling.

Can you photograph the duct and the wiring in the loft?

For the moment, leave the fan running continuously. Cost of electricity is negligible.
 
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Loft pic added , its kit with fan in the middle duct to both ends, one end of duct to bath/shower around light other end to outside. see pic from loft. I can see a white box near fan. How do I change timer..? Thanks
WhatsApp Image 2022-06-05 at 11.01.11 PM.jpeg
 
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Your have a poor quality fan. A typical cheap builders fan has a throughout nominally around 80 cubic metres per hour. You can easily get three times that. It looks to me like you have a 100mm flexible duct above the ceiling.

Can you photograph the duct and the wiring in the loft?

For the moment, leave the fan running continuously. Cost of electricity is negligible.

Also I doubt its timer problem as water condensation is happening when the fan is running...
My son takes 30 min shower during weekend, thats when we have most condensation.
At the end of shower even with fan on entire bathroom is filled like a misty morning..
 
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so more power, and longer run time, will both clear more of the damp air out

i don't recognise the one you've got

just leave the light switch on permanently until you can fix or replace it

the way it is installed, it will be easy to fit a better fan

but look for any markings to identify the old one so we can be sure of finding something more powerful.
 
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1 - that fan is the most feeble and underpowered item available and it's probably clogged with gunk as well.
2 - a much more powerful replacement should be obtained and mounted on the beam above, which will significantly reduce the noise it makes.
3 - you must also ensure there is somewhere for air to enter the bathroom such as under the door or via another vent, otherwise no fan will do anything.

Possible replacement: https://www.toolstation.com/airvent-100mm-mixed-flow-inline-extractor-fan/p70282
 
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Any suggestions..? tips..? Thanks
A couple of additional questions ...

1... Is the room kept fairly warm when used? The colder the walls /ceiling / windows etc., the more will moist water condense on it.

2... You mention a window. Does it open and, if so, have you tried opening it whilst someone is having a shower etc.?

Somewhat related to the second question above, flameport's point (3) is important. In my experience, complaints about bathroom extractor fans 'not working adequately' quite often relate to poor ventilation (inadequate opportunity for air to get into the room. If their is no vent/airbrick and/or a substantial gap under the door, it would probably be worth trying leaving the door slightly open when the room was being used (for shower etc.).

Kind Regards, John
 
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The shower curtain has a chimney effect circulating the moisture around the room. Having either no curtain, or a door which seals either top or bottom with stop the air circulating around the room, so the moisture is retained within the cubical.

I had same problem with a shower in the bath, it circulates the moisture, but with the wet room with no curtain no problem, and in this house with cubical door sealing at bottom no problem.
 
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My son takes 30 min shower during weekend, thats when we have most condensation.
At the end of shower even with fan on entire bathroom is filled like a misty morning..
Years ago we were recommended to take showers instead of a bath to save water and energy. 30 minutes is outrageously unnecessary. You need to speak to your son.
 
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Soler & Palau also do a 250m3/hr model, a lot better.

More expensive, but as you already know you have a problem, I'd lean towards a really powerful one.

https://www.tlc-direct.co.uk/Products/SLTD250SILENT.html make sure you get the Timer version.

IME they are a really first-class make.

I also agree about using rigid duct. Slope the exhaust so any condensation will drip outside, and it has a chance of washing away dust too.
 
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Ensure that there is a way that air can get into the bath room to replace the air that the fan has extracted. With out that the most powereful fan will be ineffective at removing the humid air.

The replacement air should be from inside the house. Air from outside could be cold enough to cause the humid air in the bathroom to condense to liquid on surfaces,

A gap under the bathroom door is one way to achieve this. Another way is a louvred panel in the door.
 
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In my house, the doors have gaps under them which are sufficient, but to be fair, the bathroom also has hidden gaps under the bath, and a plumbing duct, so if suction was strong, it could draw in more air. It is best if the fresh air is drawn in at floor level, as the water vapour and hot air will stratify above it and be drawn out by the high-mounted extractor.

Plumbers are usually quite generous when hacking holes in the floor for pipes.
 

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