"rbel" wrote in message ...
On Mon, 10 Sep 2012 11:14:31 +0100, "David WE Roberts"
wrote:

Life is complicated :-)

My plan is to have a bathroom fan with a humidistat, a run on timer, and
an
override switch.
I can source the parts to do this.

However when looking at fans I can see that the ones which come up as
suitable for my size room are mainly two speed fans.
O.K. find a two speed fan switch to add to the list.
However I can't seem to locate an IP44 switch which can switch a fan
between
the two speeds.

I did find
http://www.buyheliosonline.co.uk/spe...s-22-389-p.asp
but this has a 0,1,2 switch state and I don't really want a switch in the
circuit which can disable the fan if switched to the wrong setting.

Anyone have any idea of a suitable switch to use?
I just want to switch between low and high speeed, but don't want the
switch
in the loft or under the ceiling downstairs where it isn't easily
accessible.

Just a thought - are you sure that you will need both speeds? When
faced with this conundrum I decided to try my Soler & Palau fan out at
both speeds - just changing the connection between the high and low
speed fan terminals. I soon realised that the fan was so very quiet I
could happily run it at the higher speed without the need to use the
low speed at all. In your case (from memory you are using the higher
capacity TD250) you may find that you only need to use the low speed
connection.


Yes - just seems wrong to buy a two speed fan then hard wire it to one
speed.
I will probably have different setups upstairs and down, as upstairs is a
very short run, but downstairs is several metres - from the centre of the
house - and may have to go into plastic tubing (100mm soil pipe or
equivalent) to avoid loss of efficiency.

Which raises another question - how far along the run do you place the fan?
Is it better at pushing or pulling, or should you place it in the middle of
the ducting run so it is equal distances from inlet and vent?

Cheers

Dave R
--
No plan survives contact with the enemy.
[Not even bunny]

Helmuth von Moltke the Elder

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