Bathroom extractor suggestions...

[JohnW2]

Yes, it will but you may be getting too technical for a person complaining of mouldy bathrooms. As the air in a bathroom will be 'steamy' (full of visible water vapour) and the air coming in will not be then I think the result is going to be as I have thought.

Maybe. Of course, there's no such thing as 'visible water vapour' - you see 'steam' when condensation has occurred, because the RH has, at least locally, exceeded 100% for the temperature of the air. In theory, the outside air could be 'steamy' because of its low temperature, even though its actual water content (absolute humidity) was very low - look out of your window when there is a cold dawn

- try demisting your windscreen with the 'heater' set to 'cold'!

It depends how long you wait. You probably would find half an hour sat waiting unacceptable but in a bathroom it would be fine. Conversely, are you saying that a fan alone is useless? ... Would this, if so, apply to extractor fans?

As I said, preventing condensation and getting rid of it once it has occurred are really two different issues. Once one has got condensation (liquid water droplets) on walls, windscreen or whatever, on can only get rid of it by encouraging evaporation, and the best way of doing that is to increase the temperature of the air passing over it. If one is (by means of an extractor fan or car 'heater') replacing the air in the room/car with cold air from outside, the already-existing condensation may ever be eradicated. Although that outside air will (because of its low temperature) often have a very small (absolute) water vapour content, it may (again because of its low temp) have a very high RH, and therefore unable to 'accommodate' very much additional water evaporated from the condensation. If the extracted air is being replaced by warm air (probably with only 'modest' RH) from the rest of the house, then it's much more likely that the condensation will evaporate.

I maintain that the problems occur where the rest of the property is also, and always, humid - caused by the inhabitants - because of things like lots of plants, lots of washing and cooking, even many people, the bathroom may have been wiped and the cloth containing the water just left there.

That may well be true.

Kind Regards, John

 

[EFLImpudence]

Of course, there's no such thing as 'visible water vapour' - you see 'steam'

'fraid not. Steam is invisible. What you see is water vapour.

 

[JohnW2]

Of course, there's no such thing as 'visible water vapour' - you see 'steam'

'fraid not. Steam is invisible. What you see is water vapour.

Eh? Unless physics and chemistry have changed, water vapour (water is in its gaseous phase) is invisible. 'Steam' (as also clouds, fog etc.) is droplets of (liquid-phase) water suspended in air.

Kind Regards, John

 

[Grenage]

I installed a Ventaxia ACM100T, which is an in-line fan for ceilings; it's been an excellent addition.

Did you have a problem with mould before?

Yes, but the extractor wasn't the only factor; the previous occupants had a horrific amount of black mould across the walls, and the ceiling was mainly black.

I bleached everything, installed an extractor, upped the loft insulation, and repainted with Zinnser Perma-White; so it was not a solution in itself. I also maintain a constant 18C 24/7.

 

[EFLImpudence]

http://en.wikipedia.org/wiki/Steam

 

[EFLImpudence]

Both right and wrong it would seem.

Steam is water vapour and invisible.

Both are wrongly used to describe mist etc.

 

[JohnW2]

http://en.wikipedia.org/wiki/Steam

Indeed - it says:

Steam is a term for the gaseous phase of water ... in terms of the chemistry and physics, steam is invisible and cannot be seen; however, in common language it is often used to refer to the visible mist or aerosol of water droplets formed as this water vapor condenses in the presence of (cooler) air.

... which I think is largely the same as what I said, isn't it?

Kind Regards, John

 

[EFLImpudence]

Maybe, but technically incorrect.

Another case of language evolving and the misuse of democracy.

 

[JohnD]

are you calling him "common?"

 

[JohnW2]

Both right and wrong it would seem. Steam is water vapour and invisible. Both are wrongly used to describe mist etc.

Indeed. I have to say that I have not seen the word 'steam' used to refer to water vapour (gaseous-phase water), which I think we all agree is invisible - and I wouldn't say that the everyday use of the word 'steam' refers to that. Rather, when people talk of 'stream', I think they are invariably referring to the visible suspension/mist/aerosol/whatever of (liquid-phase) water droplets in some other gas (usually air), aren't they.

Kind Regards, John

 

[EFLImpudence]

Didn't like to.

 

[EFLImpudence]

Both right and wrong it would seem. Steam is water vapour and invisible. Both are wrongly used to describe mist etc.

Indeed. I have to say that I have not seen the word 'steam' used to refer to water vapour (gaseous-phase water), which I think we all agree is invisible - and I don't think that the everyday use of the word 'steam' refers not to that. Rather, when people talk of 'stream', I think they are invariably referring to the visible suspension/mist/aerosol/whatever of (liquid-phase) water droplets in some other gas (usually air).

Yes, that's the point - but they are wrong.

 

[JohnD]

that's a nice point, but presently we have to accept that languages are not dead and unchanging.

 

[JohnW2]

Yes, that's the point - but they are wrong.

Goodness knows whether I could find my dusty notes (or old textbooks) but I don't think that there were 'wrong' when I was at school and uni!!

Whatever, the argument all seems to be about what the word 'steam' means (even though I can never recall anyone every having used the word to refer to something which was invisible!) - I think we are (now) all agreed that water vapour is invisible, the only visible thing being suspended liquid water droplets (whatever one calls them). I therefore still reckon that I was probably at least partially right to question your statement:

fraid not. Steam is invisible. What you see is water vapour

... wasn't I?

Kind Regards, John.

 

[EFLImpudence]

Yes, we both new that the gaseous form of water is invisible -

You calling it only water vapour, me calling it only steam but...

...I thought clouds were water vapour and you thought they were steam.