Power Shower and Fan

[mikeelawson]

I would like to install a fan in my en suite the annoying thing however is that I do not want the fan to come on unless I have had a shower.

The thoughts I have had re this is to either have some kind of light pull so that I pull on it twice and it activates both the light and shower or

Attach the fan to the power shower so that when this goes on then the fan goes on. Given that I cannot find a light switch that does the former I would like to ask some questions based on the photo's that I have attached.

1. Is there some kind of rating system that tells you what kind of fan and output you need
2. Can the fan be placed above the shower cubicle (see picture) or is there some kind of ruling about this, somewhat like the positioning of lights
3. Has anyone extracted through the the ceiling into the attic and then out to the outside wall. My thoughts about this is that it may condense in the pipe in the ceiling and stay there
4. Given the electric switch, is it possible to put on the same circuit as the power shower so that when this goes on the fan goes on (see picture of switch and power shower)

Many thanks for any assistance.

The images are recorded on the enclosed web site
http://mysite.wanadoo-members.co.uk/mikeelawson

 

[JerryD]

this is a good link for shower fan information:

http://www.plumbingpages.com/featurepages/VentillationPHAMapril.cfm

this is a good link for calculating size of fan required:

http://www.tlc-direct.co.uk/Technical/Ventilation/Ventilation4.html

When taking shower fan ducting through the loft, there will be condensation created in the pipe. You can get a condenation trap which cleverly returns the condensed water back into the shower area (it 'drips' through a small pipe in the back corner of the shower enclosure ceiling).

The electric switch controlling your pump is 'on' all the time so you can't attach the fan supplies there. What can be done is to connect to the pump's flow switch (your pump looks like a Stuart Turner Monsoon?) - there are two flow switches but you need only to connect to one of them. Now, when the pump comes on, so will the fan. When you turn off the shower the fan will either stop immediately or run on a pre-set time depending on the type of fan you get. A timer fan is better as the shower room will need venting for many minutes after the shower is turned off.

You will still need electrical isolation for the fan don't forget.

 

[Panjandrum]

At great risk to my sanity I post this bit of information.
You will need one of those fans that keeps going after it is turned off - if you know what I mean. It needs to keep running for a good while after the shower is turned off.

Yes, the power to your pump is always on, but that is only the power to the pump control unit. The pump has a flow detector or similar device to actually power the pump only when you turn it on. You see where I am going?

Inside the pump control unit you will readily find where the power-to-pump comes from. If you use THAT as the feed to the fan switch control you get exactly what you want. There is no additional load on the pump supply - the fan is powered from a separate connection.

I did mine like this about a year ago and it has been great. In my case, the fan needs to run for about five minutes after shower-off.

I have not had any difficulties with condensation in the ducting from ceiling to outside wall, although mine is a short run and because of the routing any appreciable condensation would be trickling back into the shower. As there have been no cold drips...

The instructions that came with the fan clearly stated that it was designed to be fitted directly above the shower.

PJ

PS - if in fact I have committed some dreadful sin by fitting the fan this way, do please let me know, but gently.
PPS - apologies for repeating much of Mike's information but I missed some of that due to slow connection