Similar sized bathroom to OP. 2 big extract fans here, one above the shower and one by the window. Both on max timer settings (25ish minutes). Sueegeeing down after each shower and window kept shut in the winter because physics. I took my fans apart and gave them a good clean a month or so ago. That improved things a lot. The crud buildup in one had stopped it turning which clearly wasn't helping.
The efficiency for the fan with regard to it's displacement per hour is also effected by the length and "straightness" of the exhaust duct. Each 90 deg bend is the equivalent of an extra metre of duct length. Keep it short and straight! Also check for condensation build up in the duct causing a water blockage like a u-bend. Ideally have the duct go straight up, then down a gentle but consistent gradient to the exit point through the soffit. Any condensation should naturally drain out.
EDIT: I am just re-doing the extraction on both of our bathrooms. I am relocating the vent to right above the showers, and fitting a humidistat too. The fans will not be on timers, they will run when humidity dictates. I am using insulated ducting or rigid piping. The ribbed flexi stuff needs to be installed as taught as possible for max efficiency.
Our bathrooms (8 year old new build) were built with air intakes too. This is essentially extractor fan ducting without the fan. These bring in colder drier air to replace the warmer humid air. The vents can be screwed closed if needed
See also: Windows
I bought a massive inline fan to solve this problem. Now it vibrates the **** out of my whole attic…
My brother has this too, well, he used to. When I stayed there last xmas and he moaned about it, I convinced him that we could fix it by making a harness out of inner tubes and a piece of wood. Next morning when we'd sobered up a little, we gave it a try, fan mounted on a wooden board, board hangs from above with 2 tubes and 2 tubes attached below the board for stability. No vibration at all now and still going almost a year later.
It's so good I might patent it, the hanging board rather than the thinking of solutions to problems when half way into a bottle of port 😉
Window vac shower screen, tiles, bath sides, shower tray, window, anything with moisture on few minutes after shower. Fast, easy and efficient, my walls are tiled so I do them as well. Never use the fan anymore.
Steam / vapour isnt the only water in the room after a shower - you can do a lot to reduce humidity even with just with a squeegee and clearing all the water droplets from the shower enclosure after a shower so that water drains rather than evaporates
It’s so good I might patent it, the hanging board rather than the thinking of solutions to problems when half way into a bottle of port 😉
I think the Covid Enquiry would be held up as 'prior art' if you tried to patent the bottle of port/problem solving thing.
I vacuum the tiles and screen with a hand held thing after a shower. This helps limit condensation around my home too. I don't have an extractor fan.
I've been battling this for years. No issue with getting rid of steam but water settles on the top notch paint (Dulux diamond jobby) and it cracks over a period.
Solution: paint in summer and use that zinsser stuff, let it dry properly before showering again
Winter is the issue and I think opening the windows despite clearing the room - actually causes more condensation on the walls.
So don't really open windows now and humidistat does it's thing. Same as others in here room is probably not warm enough on the walls.
Can't figure out the logic but opening windows causes more harm that good as you're letting cold air in.
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Winter is the issue and I think opening the windows despite clearing the room – actually causes more condensation on the walls.
So don’t really open windows now and humidistat does it’s thing. Same as others in here room is probably not warm enough on the walls.
Can’t figure out the logic but opening windows causes more harm that good as you’re letting cold air in.
Same experience here with opening a window on a cold day making it worse.
I've mentioned it above, but basically if you open the window the cold air rushes in & cools down the warm air in the bathroom. Cold air can't hold as much moisture as warm air, so all of the moisture in the previously warm air, has to go somewhere as it cools. So, it condenses on the walls.
If you allow the extraction to get rid of the damp air before opening a window you lessen (or prevent completely) this condensation effect, so the walls don't get as wet.
I have a downstairs bathroom with no window, and a similar shower arrangement to Mowgli's image, without the enclosed top
I'd argue that having an extractor fan in the ceiling is not the best location as water vapour is quite dense and settles. I have an extractor fan in the wall venting outside.
Heated floors.
For when it gets really moist I've got a small desk fan standing on the corner of the 'top', and that makes a big difference clearing humidity
We have a shower room downstairs and seemed to have a lot of condensation/humidity and mould problems with it - the shower does chuck out a lot of water, the fan is not that great and there are no windows. Old house with cold stone walls.
I have a dehunidifier outside the door, but the real improvements came when I put a small squeegee on the wall (OXO Good grips) on the wall and after a shower sweep the walls down into the shower tray and then the water in the shower tray into the plug, and then later run the towel over the walls to remove the last of the moisture, plus any on the floor.
The towel then goes in the wash bin, although because of the squeegee it is much less wet than if it were used to wipe the walls down on its own. Obviously we go through towels at a rate but the washing machine has an efficient quick cycle and the tumble dryer is also quite efficient.
The fan is then enough to remove the mist in the air whilst I am finishing up shaving/etc.
The mould in particular is gone/reduced massively.
I note your fancy tiles make sweeping them down with a squeeee slightly less easy.
(I tried my karcher vacuum but it was just a pain in the backside).
Our bathroom has a solid brick external wall (Victorian House). We just leave the window open after showers and then close it an hour or so later once the walls are dry.
Room goes from soaking wet to bone dry in an hour or so even in the depths of winter.
OP hasn't replied on how the fan is controlled. Bathroom fans really need to be driven by a humidistat rather than just timer.
and as others have said, you need to heat the room as well.
Ideally, heat recovery ventilation for that room so constant ventilation without losing the heat.
https://www.bpcventilation.com/heat-recovery/heat-recovery-fans
OP hasn’t replied on how the fan is controlled.
I did, albeit in a pretty rubbish way so may have been missed - it's just on a run-on timer but I usually just leave the lights on too so it keeps running anyway.
Unfortunately, I don't really have the £££s to be buying lots of stuff to fix it – I was looking for techniques to minimise the effects really. I will be getting the kids to try the 'keep the window closed' technique to start with and see how that goes. I don't really have a way of heating the room other than the centrally-heated towel rail – but that is very powerful and does actually kick out a noticeable heat. The room itself is reasonably insulated – it's a modern (well, 1980s) house, brick-built with cavity and loft insulation. Unfortunately the underfloor heating has broken – that's a task for when the bathroom gets redone, which won't be for a few years as we only did it about six years ago.
Bigger gap. Bigger fan. Longer run time. Shorter showers.
Edit.
Unfortunately the underfloor heating has broken
Oh. That’s a pain. It makes a BIG difference.
Consider opening the window as in the absence of a bigger fan and bigger gap it will help. While also increasing your energy wastage and making the teens moan ‘why is our bathroom cold’.
2 kids, one nearly 22 other 18. Shower gets hammered every night.
Got a decent Manrose extractor that does it's best but it's a losing battle. I also have a good dehumidifier with a Tapo smart socket that's on a timer, or I just flick it on from my phone. Not ideal but works.
You can get a data logging rh monitor from Amazon for a tenner. It will show you how long it takes for rh to return to normal with either fan on or window open. The standard crappy fans can take several hours not the normal 5 minute over run. As above squeegee everything after showers. That is a lot of water that evaporates for hours after your shower soaking the walls. Humidity controlled fan, 10 mm gap under door, rigid insulated ductwork with minimum bends or straight through wall. No crushed and curled up flexi duct in loft spaces.
Re Opening the window.
I think that the efficiency of the air extraction is dependent on wind direction.
A flank wall with the wind blowing more or less straight at it isn't going to extract the air at all.
You need airflow along the side of the house to create a neg pressure in the room , to draw out the air.
Obviously redirecting the wind isn't possible, so sometimes it might be necessary to open a window on the wrong side and leave the bathroom door open. The drawback is the moisture laden air has to go further, and you have to have a window open in say , the lounge or bedroom all day . However, ime a dry house heats up very quickly once you close the windows and fire up the ch
Window after the shower - if a quick changeover, leave the window and door open at the same time for a couple of minutes. Most of the warm, humid air will leave the house. The air isn't the expensive bit to heat, it's the solid stuff so you won't lose that much energy.
