RE: Humidity problem

["Alex Clark" <alex@xxxxxxxxxxxxx>]

I bought a bathroom fan with a built in humidity sensor from B&Q.  When
you
run a bath it switches on and goes off about 30 minutes later if the
humidity has gone down again.  Humidity and timer are both adjustable.  It
wasn't much more expensive than a normal bathroom fan, and avoids switches
(apart from the isolating fused spur, of course!).

Alex.

-----Original Message-----
From: egelbeertje [mailto:r_d_k@xxxxxxx]
Sent: 21 September 2004 11:23
To: ukha_d@xxxxxxx
Subject: [ukha_d] Humidity problem

Hi,

Our bathroom is located at the innermost part of the house - so no windows
-
which created the need of forced ventilation.
Currently this is done by walking into the bathroom - knowing that you are
going to take a shower or bath - and swith on the 20 minute timer that
drives a fan sucking the air out through a vent hole and pipe it through
the
loft to the outside.
The timer (a din-module in the loft) is controlled by a pulse switch - 
push
it once and you get 20 minutes, push again it switches of. I could change
the setting so that every push extends the timer by an additional x minutes
but then I have to wait until it reaches the end of the timer cycle.

So I want to automate this one and link it to humidity detection but
haven't
been able to come up with an easy solution - preferrably hardwired -
something like "hey it's x% humidity - I will click my relay and give
a
pulse to the timer so it can work for 20 minutes - then I will measure
again
and repeat this cycle" without going into pulling wires back and forth
to a
home control device since I don't have one (yet).

Anybody out there with some bright idea would be welcome to comment.
Also some guidance on where to find humidity detectors would be a good
start.

rgds Rob