In message , Andy Hall
writes
On Wed, 16 Nov 2005 11:38:04 +0000, "mike. buckley"
wrote:

[1] Other than the obvious air flow, why have 2 rooms got them and not
the other two bedrooms?


The reason is to provide some level of ventilation - one front and one
back.

The risk if they are removed, is of condensation and stale air, mould
etc.

Condensation will happen if there are cold enough surfaces such as
uninsulated walls (are they cavity? if so are the cavities filled
with insulation? Are the windows single or double glazed?

For a bathroom, you do need to get rid of the moist air. If the vent
is removed, then an extractor fan is a good idea.

Recent double glazing has trickle vents so that a minimum of
ventilation can be provided.



Ta for that. We get a lot of condensation in the main bedroom, this has
a vent, but it doesn't make any difference.

The windows in the bathroom are approx 15 years old double glazing, and
as a result are pretty crap. We only get condensation during
baths/showers and we're happy to open the window to cure that. I've only
seen the trickle vents on wood double glazing, not on uPVC, but that's
not to say it's not available! Might go for an extractor fan, but when
it's off don't you get a draft anyway, I'll have to look into that.

The walls are double brick, from what I saw of them when we had our
conservatory done, the cavity if there is one, is tiny, less than an
inch, so insulation is probably a waste of time.

--
Mike Buckley
RD350LC2
http://www.toastyhamster.org
BONY#38