On Monday, November 5, 2012 6:08:08 PM UTC, stuart noble wrote:


Most of the time such meaures aren't being taken, and water vapour is
being put into the air all the time a house is occupied. Heating
enables it to carry more water vapour, but obviously that alone
wouldnt keep it dry for long,

Obviously it would. With the thermostat at 20 degs the air will carry
more water than you can produce by breathing and cooking. That is
precisely why it isn't a problem for normal people in normal houses.

Even if heating increased vapour carrying ability by 10 or 100x, the amount of water vapour it can carry is always finite. But the addition of vapour to the air by living is endless. Its patently obvious that air can't carry an endless amount of vapour, so heat alone doesn't resolve things.


there is then ventilation which
replaces interior air with greater vapour content with outdoor air
with lower water vapour content.

How much vapour content there is, in or out, depends on temperature.

Yes

You
can't just say that the interior has a higher vapour content.

Lordy. We take in the outdoor air and add more vapour from breathing, cooking and washing. Do you think that dries the air?

In walls without a VB, you also have higher water vapour content on
one side than the other, so the vapour slowly migrates through the
walls from inside to outside.

Its basic physics.

Fortunately the average housewife knows perfectly well how to keep a
house dry and healthy without your in-depth knowledge of physics.

Whether a home stays dry is more to do with its design & construction. Only a minority of buildings require significant care over interior activities.

You continue to adopt this high handed and patronising attitude to
anyone that disagrees with you, which I don't find at all constructive

Well, you demonstrate a determined failure to grasp the basics, you can't be bothered to read up on the subject, yet you insist your confusion is right. Lets just agree to disagree, its easier.


NT