Steamy bathroom help

thebullsback

is the extraction vent inside the shower cubicle area? if not I would move it also I've noticed that after I have showered our tiled walls are not sweating as much as after my wife showers because she has the water very hot and I have a cooler shower.

FFHillbilly

I'd fit a bigger radiator in there, if it was warmer you are giving the fan longer to change the air before cooling and condensation occurs.
you need "make up air" for the fan too, consider cutting 1" off the bottom of the door or installing a grill in it. if the door is shut and there are no other holes for air to get into the room, the fan is doing noting when the door is shut

FlaatusGoat

ThisIsWeird said:

This is all a bit strange, Flaatus.
It's a 'small' bathroom, so presumably air exchange rates will be pretty fast. It's windowless - does that mean no external wall either? And you have a powerful extractor. Blimey.
Such visible steam in the air and on surfaces does usually suggest it's a cold room - what temp is it at?
But, since the new powerful extractor also ain't doing the job, I wonder if it's as Lorian says - the door is just too well sealed? The extractor simply cannot extract from a self-made partial vacuum. 
Q - do your ears bleed when you use the shower? Eyes bulge? Cool.
Could you try what Lorian suggests and see how it compares - the door literally cracked open?
And is there plenty of loft insulation above the ceiling?
Failing that, yes, smooth ducting, going up to 150mm, and a matching - even more powerful - extractor should sort it, and the addition of a switchable humidistat control is also good, if you are currently turning the fan off too early; you may think it's fully dry, but it might not be, so the room begins at a disadvantage the next time. Or, just leave the current fan running for ages - they use next to nothing - with the door cracked open (or even fully open, provided you are confident the steam won't escape into the house instead...)
Oh, how long is the ducting, and how large the exit grill?

Nope! No external wall. The family bathroom is on the terraced / joined wall. Bit of an odd configuration. Trouble with the door, if I leave it open a crack the firealarm gets cranky. I've had some not-so-great experiences of jumping out of the shower, dripping, and having to extend myself to press the fire alarm button. Not fun! There is a fairly decent gap under the door and you can really feel quite a breeze around your ankles after finishing the said shower and standing by the door. The loft is very well insulated by the way.

Got about 3.5m of plastic/PVC ducting that runs through the loft to a external-wall vent. I think that's all OK. What I'm going to do (based on advice here!) is rather than relying solely on the inline fan to do all the work, is also a humidistat/fan on the ceiling of the bathroom. Got one ordered. My theory is the inline fan can do the pulling through the ducting, and the ceiling fan can do the pushing from the bathroom. The old grill that I had up there to cover the ceiling vent hole would typically be dripping with condensation during showers....

ThisIsWeird

Blimey. So it's a 'warm' room, with a well insulated ceiling, and a good ventilating air gap under the door. And it's still a sauna.
I can only assume your existing fan isn't able to draw properly. When running, if you raise a sheet of tissue paper up to the grill, how close do you have to go before it sucks it up? Does it feel strong? Does the tissue 'form' around the grills?
Could the exiting grill be a limiting factor?
Personally, I'd be looking to use a single inline fan, but beef it up as required - 5", solid plastic ducting, lots of M3 rate, an unrestricting outer grill.

Grenage

A lot of extractor fans are awfully weak.  A decent inline fan will probably sort you out.  We fitted a ventaxia at the last place and it did the job nicely.